1990 Q45 Brake Pad R&R (BRAKE PADS WORN)

[tangalora]

Heath,Notice that last photo I posted (from Popular Mechanics) is the norm in that the brake rotor runout test is performed with the calipers mounted in position.

However, note the photo below (also from the URLs I posted previously) which shows brake rotor runout being tested with the calipers swung out of the way.

[Q45tech]

Note GM uses 0.002" as spec vs Nissans old 0.0028"

Many recommend 0.0005" as what is really needed.

I succeded in getting less than 0.001" once without using brakealign shims. After about an hour of fine grinding and polishing the hub and inside rotor hat.

I doubt that one car in 10,000 has the brake really checked [matched] with a dial indicator - takes too much time as most owners are uneducated about it........all they want is the $99 special.

Obviously GM has problems as do most other brands or there won't be proceedures and TSB telling you how to fix the problems.

Try getting the dealers to do it, surely at least one tech has the test equipment...............they will just use the on the car lathe instead of fixing the bearing or hub. But if the bearing wobbles it will warp a good new rotor.

See why I say that brakes are the most expensive maintenance item on the Q.........not new pads or rotors just labor to keep the system in spec. Say 4 hours every 6,000 miles= $700

Of course tires plus Accurate rebalancing every 3,000 miles is a close runner up at $25 per tire on a Hunter 9700.=$500

I have to do this myself since even I won't spend that much.

[tangalora]

By the way, again, to give the next guy a leg up on us, I researched prices for the most recommended brake-rotor-runout tool with the (best to worst) result of:

• $131.61 CEN6450 CEN-6450.jpg Central Tools / Central Lighting Brake Rotor/Ball Joint Gage Set
• http://www.thetoolwarehouse.net/shop/CEN-6450.html
• $132.25 CEN6450 CENTRAL TOOLS ROTOR RUNOUT/BALL JOINT GAUGE; 0-1IN; FLEX ARM
• http://www.sjdiscounttools.com/cen-6450.html
• $142.95 CEN_6450
• http://toolcraze.com/Merchant2/merchant.mv (search for CEN_6450)
• $143.95 CEN6450
• http://www.toolrage.com/cgi-bin/istore. ... words=CEN-
• $145.00 6450 Dial Indicator Brake Rotor / Ball Joint Gauge Set Central Tools
• http://store.yahoo.com/bradystools/diinbrrobajo.html
• $149.45 CEN6450
• http://store.yahoo.com/autotoolexpress/ ... baljo.html
• $149.50 CEN6450
• http://www.dmstools.com/master/cen6450.htm
• $149.99 CEN6450 Central Tool Dial Indicator Brake Rotor/Ball Joint Gauge Set
• http://www.autotestsys.com/Merchant2/merchant.mv (search for 6450)
• $152.13 6450 Dial Indicator Brake Rotor / Ball Joint Gauge Set Central Tools
• http://store.yahoo.com/bradystools/dialinbrakro.html
• $155.50 CEN-6450 Dial Indicator 0-1"Rotor Runout/Ball Joint Gauge - Flex Arm
• http://www.drivewerks.com/catalog/ShopC ... 3_pg12.htm
• $268.40 CEN6450
• http://www.autods.com.ua/shop/TTW289.html

This is not claimed list price, but, actual sales price (sans tax & shipping); all for the exact same item; which all goes to prove, yet again, that you don't necessarily get more if you pay more ... all you get is you pay more.

(Admittedly, the price isn't all that different, as long as you stay away from the 268 dollar offering).

[tangalora]

Dennis or Joe (at EverythingNissan),

I'm very disturbed about one item which was not adequately resolved in this thread yet.

Today I called 800-662-6200 (press 7) & spoke to "Michelle" in the Infiniti Consumer Affairs office on 18501 South Figueroa Street in Gardena CA 90248-0191

I asked her for the COMPOSITION of the front pads (41060-64U91) and of the rear replacement pads (44060-66U85).

She came back quickly (a bit too quickly) after supposedly talking to the technical experts with the verbatim quote "these pads are a mixture of ceramic & semi-metallic materials". I questioned that (especially since she didn't make any distinction between the front & rears and asked her to doublecheck.

Again, she came back with the same answer from the Infiniti experts. I asked another dealership - which said "CERAMIC" for the fronts, semi-metallic for the rears. Yet, a dealership only miles away from that one said "SEMI-METALLIC" for both.

Now, I'm committed to the OEM pads already (having returned my Raybestos semi-metallics); but, honestly, if Infiniti can't even tell me what material their pads are, it sort of ruins my justification for going OEM. Heck, I can go to the local parts store and I'm sure they'll sell me pads that truly are ceramic or truly are semi-metallic.

QUESTION: Doesn't anyone in Infiniti-land really know what material these U91 & U85 pads really are? (Is there an address other than the one I list above where I can ask Infiniti?).

[Q451990]

I'm sure somebody knows what's in there - but getting in touch with them is the real issue. Sort of like the movie Office Space, with the guy who says "I deal with the g.. d.... customers so the engineers don't have to - I have people skills!" except you have a language barrier in the middle of it too.

As far as my question about the caliper - the problem I had is finding a way to hold the rotor and hub securely while torquing the lug nuts down. Without the caliper in place (and an assistant pressing the brake pedal) how do you hold the fronts steady while torquing them down? Although the caliper swings up, the caliper bracket is too close to allow you to take the rotor off and rotate it to the next position.

Heath

[911/Q45]

Can you stick a screwdriver in the rotor ventilation slots and jam it against the caliper hardware to torque the lug nuts?

[tangalora]

I received the front & rear pads & hardware kits today from Joe at EverythingNissan, along with the runout dial-gauge vise-grip flex-arm jig from sjdiscounttools.

Looks like, this weekend, weather permitting, I'll be skinning my knuckles against cold hard steel & writing to tell about it.

For the record, the $45.70 #41080-60U27 Nissan "HARDWARE KIT-FR" for the front apparently consists of the following:

• (4) #41083-60U04 SPR-RET, PAD
• (4) #41083-60U05 SPR-RET, PAD
• (4) #41084-60U00 SHIM
• (2) #41085-60U00 SHIM-COVER, INNER
• (2) #41085-60U01 SHIM-COVER, OUTER
• (2) #41003-03P25 GREASE (2.5g)

Whilst the $45.70 #41080-60U25 Nissan "HARDWARE KIT-RE" for the rear apparently consists of the following:[/list][*](4) #44083-44F00 CLIP-PAD[*](2) #44084-60U00 SHIM-OUTER[*](2) #44084-60U01 SHIM-INNER[*](2) #44085-60U00 COVER-SHIM[*](2) #44086-60U00 SHIM-INSULATOR[/list] Bear in mind, the similar-cost Raybestos pads shown in the photo below contained only the equivalent of the (4) #41084-60U00 SHIM hardware (both pad sets contained the right-side electronic wear sensor).

By the way, in diagram SBR019B on page BR-20 (front) & BR-24 (rear) of the 1990 Q45 Factory Shop Manual, Infiniti clearly shows the dial-gauge check of rotor runout (max = 0.0028 inches, 0.07 mm) is performed with no calipers & with ONLY two opposing (12mm x 1.25 threads per millimeter) open-ended nuts securing the rotor to the wheel hub.

The corresponding check for rotor thickness (front 1.024 inches, rear 0.315 inches) also shows no calipers & the two 12x1.25 open-ended nuts securing the rotor to the hub.

However, as noted in both my recent sunvisor repair & in my original fuel-pump-and-controller repair, the FSM is known to be wrong (in both my cases at least). So, I'm inclined to assume it's wrong also in this situation; and therefore to go with Dennis' suggestion to use the original 5 cap nuts with washers replacing the space left by the wheel no longer being there.

[Q451990]

Again I ask... how are you going to hold the rotors in place on the front while you tighten the nuts (either two or five)??

Heath

(I'm not hounding you on this, just seeing if anyone knows)

[Q45tech]

If you are going to fix runout do yourself a favor and get 0.003" and 0.006" Bakealign shims AS:You can spend all day trying 5 positions, grinding and smoothing and still be out of spec.

I have been able to get 18 months [24,000 miles and 4 trueings]out of one 0.006" shim and still maintain 0.001" finished error.

Hopefully the new calipers will extended the warp time some, I am at 5800 miles since the last trueing so far so good.

[tangalora]

It's early in the am & I've been working on the brakes all night. What is taking so long is I've snapped over 400 photos so far, and, well, my camera batteries died many times & I had to recharge them to take each photo for you guys. I just came in out of the cold to double-check on the lug-nut torquing specs from Dennis; but I figured I'd answer Heath's question here and now in the forum:

Quote » the problem I had is finding a way to hold the rotor and hub securely while torquing the lug nuts down. Without the caliper in place (and an assistant pressing the brake pedal) how do you hold the fronts steady while torquing them down? [/quote]

What I did was jam a pry bar (which I obtained for free many years ago from a thief (long story) who tried to steal my 280Z yet inexplicably left the prybar on the ground. That caused me to buy a 300Z, which came with an alarm system.) 'told you it was a long story.

Anyway, the thief's pry bar did the trick. I just gently placed it into the rotor vents and as I torqued down the rotor, the pry-bar handle pressed against the kingpin (or strut or whatever that thingey is) allowing me to torque the lug nuts down for checking runout.

Tangalora

[tangalora]

Quote »Dennis: Don't forget to use some large washers between the rotor hat and the lugnuts and torque all lugnuts at least to 60 ft/lbs ... so the rotor is stressed as normally installed.[/quote]

I don't have washers on hand to fit the lug bolts. Normally I'd take a trip to the parts store, but, it's almost daylight so I doubt any would be open (24 hour parts would be nice .

Here is a side view, for Heath, showing what seems to work. I haven't torqued it to 60 pound feet yet, but I will as soon as I finish these hasty posts.

[tangalora]

I apologize for the dark photos. All I have on hand is a halogen work light as the flash is anemic due to the recharge per picture. I'm doing what I can for you, but, I can't wait 'till daylight as I have the 6am shift this week (on Martin's birthday, no less!).

Since I don't have the washers, my open-end lug nuts will have to do (I'm doing all 5 instead of just two ... if some is good, more should be better). What do I lose by not having the washers? That is, what was their purpose anyway. I could see if they were cap nuts how the washers would be needed; but these lug nuts are open ended & tapered at the business end. Please let me know what I'm missing.

I just stepped outside and snapped this better lit closeup shot for Heath. I hope it shows what seems to be working. I torqued one nut (so far) down to 60 pound feet and the pry bar held up without groaning.

[Q451990]

Execllent idea on the pry bar!

Thanks!

Heath

[Q45tech]

See how hard it is to get to 0.001"...........the T3 techs laugh at me when I go thru the correct proceedure.Can you imagine a dealership doing this, much less a Breakeo Shop. Each rotor would/does take an 45 min-hour [$75-$100] extra labor. I can promise that every discount brake job is out of spec after completed.

The on car lathe saves so much time and promises a better end result because the techs can't make too many mistakes.

[tangalora]

The key point on the prybar is the BENT TIP (last 1.5 inches is offset at about 30 degrees). Another key point is the very strong square cross-section shank. Lastly, it needs to be the right size, about 12 inches in total length (7 inches of shank, 5 inches of handle) & 1/2 inch in tip width to fit absolutely perfectly in the Q45 front brake rotor vent & then to curve inward at so as to come to a stop against the Infiniti strut mount (A frame?).

Here's a shot of the thieve's Snap-On "#SPB 12" working perfectly holding back the front left rotor as I unscrew the five now-torqued-to-60-pound-feet lug nuts on the brake rotor.

The beauty is that the rotor doesn't budge a micron; and the bent-blade prybar pops back out of the brake rotor vents without sticking a bit.

[tangalora]

I misspelled the Snap-on part number in the photo above.

Apparently, from a quick Internet search, the Snap-on part number is SPB 12 (which probably stands for S=Snap-on, P=pry, B=bar, 12=total length) which seems to list for about $29 dollars.

A corresponding Sears "Craftsman 12 in. Pry Bar, with 7 in. Curved Bladed Screwdriver" part number seems to be Sears item #00943275000 (Mfr. model #43275) which seems to list for less than half that price ($12 dollars).

[tangalora]

The good news is (after burnishing) my 1990 Infiniti Q45 front brakes were done (rotor runout was never greater than .002 inch & rotor thickness was never less than 1.055 inch & no grooves were greater than .060 inch judged by the aforementioned documented Poplular Mechanics "dime" methodology).

Burnishing was accomplished by following as close to Dennis' aforementioned documented "EPR 2000 Evaluation of Replacement Brake Pads for Poilce Patrol Vehicles" procedure as I could get (in early morning traffic). Specifically, the recommended burnish procedure consists of the following:

• Ten stops from 45 mph at an average deceleration rate of approximately 15 feet/second^2, with brake applications at two-mile intervals.
• Six stops from 60 mph at an average deceleration rate of 27 feet/second^2, with brake applications at 15-second intervals

MAY I ASK AN OFF-TOPIC QUESTION?

I should, I guess, ask this non-brake issue in a new thread, but, I'm perplexed about how it's related to yesterday's brake job. For about two years now the automatic transmission shift interlock has been 'broken' in that I could not get the Q45 out of park without pressing both the button on the shift selector lever and the override switch (called the "shift lock release" on the diagram on page AT-99 of the '90 FSM).

Miraculously, in my ride to work this morning, the shift-lock problem fixed itself!Now, When I stepped on the brake in preparation to start Q'sey, I hearrd a distinct click (which I don't remember hearing before); this click happens each time I step on the brake with the shift lever in park. This unexpected wondrous event somehow frees up the transmission lever so that I can now shift into drive once the Q starts, without having to press both buttons anymore. Come to think of it, I just had an epiphany. The need to press the shift lock release might just have started at about the time of my last mechanic's brake job, about two years ago.

QUESTION: What specifically did I do in my basic front brake job that somehow fixed this long-standing problem?

[Q451990]

I can't imagine the brake job and shift lock were related... Maybe all of those stop-n-go's for the brake bedding worked something loose. I've heard of those being replaced before - in fact the service records on "Q2" show that it was replaced under the warranty at some point.

Heath

[tangalora]

Quote »Maybe all of those stop-n-go's for the brake bedding worked something loose.[/quote]I should have made it more clear that as soon as I sat in Q'sie for the first time after replacing both front pads, that the new clicking sound was heard as I stepped on the brake pedal while the engine was idling with the transmission in Park.

The clicking is clearly related to the brake pedal being pressed (as it clicks each time I press the brake pedal & release while the engine is idling with the transmission in Park). The click is clearly coming from underneath where the shift-lever resides (that is, just above the transmission). I can even feel a slight vibration with my hand as it clicks.

So, it wasn't the brake-burnishing procedure which 'fixed' the broken lock-out switch. Perhaps just jacking the two-ton Q in the air did the trick (although I've jacked it up before). Or, maybe there's some connection between the front right wear sensor circuitry that was re-attached (somehow).

The photo below shows me removing the lower caliper pin on the backside of the passenger front calipers (I always have to step on the wrenches or bang them with a hammer to break the bolts loose). Notice there is a connector coming off the brake sensor which fits into a unit (tucked off to the lower right in this midnight-flash photo) about the size of a jar of nail polish. What do you suppose is inside that 'jar of nail polish"? I suspect there's more to it than just wires as the object is larger than it would need to be if it were merely a waterproof shockproof connector.

Q: Do you suppose this obvious electrical connection has any link to the transmission brake-related override switch?

[tangalora]

Here's a closeup of that (unknown to me) fingernail-polish jar sized brake-related electrical component mounted on the back side of the passenger side calipers on the Q45.

Do you know what this component does?(It seems too large to be just a harness connector.) Do you think this switch is related to the transmission brake/park over-ride mechanism in any manner?

[Q451990]

My guess is that it has something to do with the ABS sensor... still not shift-lock related - at least to my knowledge.

Heath

[tangalora]

Oh, well, back on topic. The good news is the brake-related transmission shift lock-out-switch relay (by divine intervention perhaps), healed itself, without any overt prompting from me (after two years, I was gonna' get to it, I swear).

The other bit of good news is that the front pads were worn barely down to the tip of the wear sensor, going only so far as to scuff the sensor plastic off allowing a teeny tiny tip of wire to protrude. You'd think that trip'd the sensor.

The bad news is, my Infiniti Q45 "Brake Pads Worn" light is still lit. That's it. I can't put it off any longer. It's finally time to do it in the rear. I'll try it for the first time this weekend. Yes, I'll photo each and every step to add to the article that isn't written yet so those who come after me can do the job easier.

By the way, I'm glad you NICO guys recommended parts from Joe at EVERYTHINGNISSAN. Why? Not because of the pads (which even Infiniti can't seem to say what they're truly made up of); but because of the brake-hardware kit!

Look'it the photo below of the old hardware vs the new. Notice the bent, worn, cracked, over-re-used canyon clips. Ouwwhh. That hardware replacement was apparently long overdue.

Tangalora

[Q451990]

My rears always hit the sensor before the fronts... I'm pretty confident that's the reason for your continued "Brake Pads Worn" message.

Heath

[Q45tech]

The Q uses a greater percentage of rear brakes than any other FWD car.......why the faster wear and more warage on the rear.

Since the static 54% front weight goes to 70% in a panic stop......46% >30% rear brake bias is about double most RWD cars.

Both front tires equal or exceed their 1521 pound rating [at 35 psi] for the duration of the panic stop...........but 3-4 seconds is usually safe........even 15 seconds.

Be interesting to take CURRENT tires up to 150 mph [multiple laps] in summmer track to maximize heat them do a panic stop on the next straight away. This worked in oem testing with Michelin and pretty new oem pads back in 1989.

Would the systems survive today on your car.

[tangalora]

Before I move on to the rears and forget how I did the fronts, I'd better document for posterity the steps I took for others to benefit.

Here's the tangalora recommended front-brake R&R procedure as best I konw it (photos for each and every step to be edited, texted, shrunk, & posted when I have (lots) more time)

• Assume "Brake Pads Worn" lights up on your Infiniti Q45 dashboard (mine is a '90 with 125K miles)
• Read the "Front Disk Brake" section of the FSM (For 1990, it's BR-17 to BR-20)
• Read the dozen articles on brake pad replacement previously posted to this Nico thread (specifically with regard to different materials on each axle)
• Note particularly the September 2003 Consumer Reports article which summrized that all pads of the same material are about the same
• Note especially the inability of this member to conclusively obtain the material of the OEM pads
• Yet, note the importance of proper pad material matching in the Police testing of brake pads as noted in this thread
• Make your own decision about which brake pads to purchase; but definately pick up the previously noted hardware kit from Joe!
• Place a chock behind each rear wheel & set the (rear) parking brake
• Remove the three-inch diameter BBS Infiniti marquee hubcap (if equipped) on the aluminum wheels with a special BBS hexagon-shaped removal tool (available from your Infiniti or BMW dealer)
• Place the BBS hubcap in your parts bin (in my case, a large red plastic fruit bowl)
• Loosen the five 13/16 inch lug nuts on each front wheel (they don't seem to be metric; why not?) in a clockwise star pattern (1,3,5,2,4)
• Place a floor jack under the front (frame) & jack the wheels about 1 inch off the ground
• Place 1 jack stand under each A-frame lower control arm (or whatever that is) & gently (if possible) lower the car onto the two jack stands
• Leave the floor jack slightly touching the frame (for additional safety) & try to gently rock the car off the 2 jack stands (better now than later)
• The Q45 should not budge
• Open the hood & remove the brake master cylinder reservoir cap (leave the cap upended on the master cylinder)
• Do not top off the brake master cylinder reservoir with brake fluid (less is better for now)
• If the brake master cylinder reservoir fluid level is high, place a shop rag around the brake master cylinder to soak up any overflow due to spreading of the brake caliper pistons which will soon occur
• Mark each wheel with chalk (L, R) so that you don't mix them up upon replacement.
• Remove the five right wheel lug nuts and place them in a large plastic fruit bowl (or other suitable parts bin)
• On the right brake side, locate the brake sensor two-pronged waterproof harness connector bolted to the back side of the right caliper
• Disconnect the brake sensor connector
• With a 12mm box or socket wrench, remove the 12mm bolt holding the brake sensor harness connector bracket to the caliper body
• Allow the brake sensor harness connector & bracket to swing freely (out of your way)
• With a 17mm box or socket wrench, remove the 17mm lower caliper pin bolt (there is no need to remove the upper caliper pin at this time)
• It's not noted in the 1990 FSM, but, you must also remove the bent-steel spring clip securing the brake hose to the frame (otherwise you'll barely be able to swing the calipers high enough to remove the pads & certainly not high enough to remove the caliper from the rotor)
• With a pry bar or large chisel, bang out the bent-steel 2-inch spring clip securing the brake line to the chassis
• Place the spring clip in your parts bin
• With an up and back motion, free the brake line from the chassis clamp
• Swing the brake caliper upward free of the brake rotor & secure to the frame to prevent hose damage
• Note: The '90 FSM suggests wiring but I found tie wrapping to the strut coils to be easier than wiring
• Pop off the outer shim steel cover, the rubberized perforated outer shim, and the outer brake pad (keeping them together as some are a different shape than on the inner side which has the sensor embedded in the brake pad)
• Inspect this outer pad for scoring or for uneven wear for diagnostic purposes ('90 FSM wear limit is listed as 0.079 inches or 2mm)
• Note: OEM pads have a center groove cut in them to help determine wear (if the groove is gone, the pad is kaput)
• Rubber band the three (cover, shim, pad), label, and place in your parts bin for safekeeping & for reassembly hints
• Pop off the inner shim steel cover, rubberized preforated shim, & inboard right brake pad with embedded sensor
• Again, inspect the brake pad for scoring, uneven wear, sensor condition, and other diagnostic purposes
• Again, rubber band the set, mark the pad with chalk, & place in your parts bin
• Inspect the two caliper piston cups & rubber boots for scoring, rust, wear, foreign material (bubble gum?), or other potential damage (as per the FSM)
• Place a disc brake caliper piston spreading tool in the business end of the now naked caliper and twist the handle of the spreader to push the pistons back flush into the caliper
• Bear in mind you may need to add a flat steel plate to distribute the spreader's force evenly across both piston cups (I used a half-inch wide six-inch long 3/8 inch thick steel motorcycle tire iron to distribute the force because my disc spreader had only one spreading bolt)
• Doublecheck the brake master cylinder reservoir fluid level (which will rise as you push the pistons back) for overflowing (wipe up any mess)
• Make sure you mark the rotor & a lug nut BEFORE any next steps (you'll see why later) with chalk (or other suitable marking material)
• Check each face of the brake rotor visually for scoring, roughness, cracks, chips, etc.
• Note that scoring, objectively, can be over 50 thousands of an inch (the thickness of a dime) & still be acceptable in some articles (read the articles)
• Some articles suggest scoring be subjectively checked with a ball-point pen, or your fingernail, seeing if the pen leaves gaps or if your fingernail catches
• The 1990 Infiniti Factory Shop Manual (FSM) does not seem to provide a limit for scoring thickness or depth (so rely on the articles or Nico mechanics)
• If you read (and believe) the articles, you'll likely not remove the rotors for smoothing on a lathe unless scoring is severe (greater than .060 inch)
• With the caliper out of the way, use a micrometer to check the brake rotor thickness in multiple places (I used a 1-inch mic, but, a 2-inch mic would be more appropriate)
• Measure clockwise, at least, starting at the marked lug nut moving clockwise & write down the measurements as you go.
• When finished, check the deviation between each measurement; this rotor thickness variation limit is not listed in the '90 FSM, but, standards are listed in the aforementioned articles
• Note: There is a steel backing plate preventing you from accessing the rotor thickness from any other place other than where the calipers lay
• In my case, the rotor was 1.055 inches to 1.056 inches in thickness, measured about a dozen times at various locations ('90 FSM indicates minimum of 1.024 inches or 26 mm)
• Place a 12 inch angled-end pry bar (Snap-On SPB 12 with 7 inch blade & 5 inch handle, or Sears' equivalent) sidewise in a rotor vent, resting against the A-frame top member
• Following the '90 FSM, place two flat-sided 12mm x 1.25mm/mm steel nuts (not tapered lug nuts) on two opposing lug bolts (torque not specified in the FSM; use 60 pound feet)
• In my case, I used the existing 13/16 inch lug nuts (but you should follow Nico recommendations to add a strong steel washer or two in order to protect the rotor from cracking as the tapered lug nuts dig in)
• Torque those two (or all five) nuts to about 60 pound feet (allowing the pry bar to rest against the A frame to prevent the rotors from rotating)
• Clamp a flexible dial gauge jig vise-grip (see tool references previous in this thread) to the tie-rod-end nut and bend the flex arm horizontally around the rotor (see photos)
• Position the pin-type dial gauge against the rotor at about the center of where the pad meets the steel (do not try (like I did) too hard to zero the gauge)
• Run a fast hand spin the rotor (at about one revolution per five to ten seconds) to 'seat' the dial gauge (this I learned by trial & error)
• Then hand spin the rotor slowly (at about one revolution per fifteen to twenty seconds) taking note of the TOTAL runout ('90 FSM limit is 0.0028 inches or 0.07 mm)
• In my case, the rotor runout was (at maximum) 0.002 inches
• If desired, you may wish to remove the rotor.
• To remove the rotor, you must remove the caliper.
• Note: It helps, from time to time, to turn the steering wheel inward or outward, as needed, for better access to inboard & outboard components; these steps will be omitted from this discussion
• The caliper is EASILY removed merely by pulling gently on the caliper such that the upper pin slides out of its slot & rubber boot (you do not need to spin out the upper pin!)
• To unstick the rotor from the hub, you could screw a threaded bolt in each of the two holes provided for this purpose but I just banged the rotor off the hub with a rubber mallet
• Recheck brake rotor runout with the rotor in the next position clockwise (this is why you marked the first bolt & the corresponding rotor's slotted edge with chalk).
• Continue reindexing the rotor until all five lug positions have been tried with rounout measured; choose the one with the best measurment; recheck runout.
• Note: This might be a good time to check for bearing lubrication, bearing wear, ball joint wear, etc. but I don't know how to check this stuff. Next time ...
• Note: Special brake shims may be needed (as noted in this Nico thread) if runout exceeds 0.0028 inches in all cases above. In my case, shims & multiple reindexing was not attempted.
• Now it's time to clean & inspect (what I call the brake caliper 'canyon clips' & which the '90 FSM calls "pad retainers")
• These important little parts are shiny steel plates bent to shape fitted into the cast caliper arms to hold the brake pads securely
• First note that there are four 'canyon clips' (pad retainers) per caliper & note they are of two similar looking (but different) shapes (they are mirror images of each other)
• The rule for the canyon clips is, if you forget which mirror-image shape goes where, use tangalora's "FLAT SIDE TOWARD ROTOR" rule (see photos to be posted later)!
• With a small screwdriver or prybar, pop out the outboard right rotor top canyon clip (notice the flat side was inward).
• Compare the shape that of it's replacement from the new hardware kit, & press fit the new top canyon clip into the caliper arm
• Do the same for the (mirror image) outboard lower caliper arm canyon clip (remember, flat side toward rotor)
• Remove the cotton from one end of a Q-tip cotton swab (or grab a toothpick and crush the pointy end a bit)
• Stick the cotton swab or crushed-point toothpick into the brake grease provided in your new hardware kit from Joe at EVERYTHINGNISSAN & grab a glob of shiny golden grease
• I'm not sure if we should swab the caliper canyon clips; but I did (I found the denuded cotton swab preferable to the crushed-tip toothpick) PLEASE ADVISE!
• Also clean, inspect, and regrease both the caliper lower & upper pins (upper pins require aforementioned caliper removal off the brake rotor)
• At this time, you can cut the tie wrap (or steel wire) holding the calipers up and out of the way (yet protecting the all-important brake hoses from damage)
• Unscrew the disc brake spreader & remove any steel shapes placed to spread pressure to keep both piston cups flush with the caliper arm
• Lower the empty brake caliper arms back onto the brake rotor (if you removed the rotor, the pin will need to be reinserted into its rubber boot & caliper holes)
• Place the end tabs of the new brake pad into the newly greased outboard canyon clips & press against the rotor
• Place the end tabs of the new brake pad shim into the newly greased outboard canyon clips & press against the brake pad
• Place the end tabs of the new brake shim cover into the newly greased outboard canyon clips & press against the brake pad shim
• Repeat the canyon clip replacement, greasing, & pad, shim, cover replacement for the inboard caliper side.
• The only difference between the outboard & inboard side is the previously noted shape of the shim & shim cover curves around the brake sensor in the inboard right brake pad
• Place the 17mm lower caliper bolt in place & tighten to specifications (12 to 14 pound feet according to the '90 FSM)
• If you actually unscrewed the upper caliper slide pin (I didn't), tighten it to specifications (61 to 69 pound feed according to the '90 FSM)
• Note: The upper slide pin does not have to be unscrewed in order to remove the calipers from the brake rotor!
• Place the 12mm brake sensor harness connector bracket bolt in place & tighten to specifications (?) to secure the right-side brake sensor connection to the inboard side of the caliper
• Push the brake hose up and in, into its mating bracket & hammer in the spring clip using a hard mallet (taking care to insert the spring clip in the correct direction)
• Doublecheck the brake-hose-bracket spring-clip direction by looking at the pristine untouched left side of the Q45 (that's why I do one side at a time) as it fits either way but is secure only in one direction (see photos to be uploaded)
• Replace wheel, hand tighten the five lug nuts in a star pattern clockwise & move on from the right side to the left side of the Q45
• On the left side, repeat all steps with the only exception being there is no brake sensor on the inboard side of the left brake pads
• Note: Strangely enough, the left side inboard-only pad shim and shim cover are shaped as if there is was a sensor, so take note upon disassembly & reassembly.
• Check the underside of the car for any left-over tools, towels, grease packs, and kittens who have found a safe haven from the cold wet drizzle
• After both wheels have been hand tightened, jack the car up slightly in order to remove the jack stands, and lower the Q45 as gently as possible
• Note: In my case, no matter how hard I try, the car shudders down with a jolt faster than a wary cat can get out from under, as I (try to) slowly twist the floor jack handle.
• Remove and stow away the floor jack, jack stands, and rear wheel chocks
• Tighten the five tapered lug nuts on each wheel in a star pattern clockwise to 60 pound feet
• Replace the BBS hubcap on the aluminium wheels and twist clockwise to make sure it clicks in place (it cost me $45 for a new Infiniti marquee BBS hub cap the last time I didn't do that)
• Start the engine & make a note of the status of the "Brake Pads Worn" dash indicator (which does not indicate whether it's front or rear righ-side inboard pads which are worn)
• Remove the parking brake & take your Q45 for a test drive before performing the high-speed 25 mile burnishing procedure as noted in the police related previously referenced articles
• Report back to NICO your status & what you've learned so that others benefit

Questions (considering my steering wheel wobbles slightly, at speed):

• Should I have greased the shiny steel canyon-clips (pad retainers)?
• Did I miss anything that needed to be greased (I had plenty left over)?
• How could I have checked the Q45 for wheel bearing wear?
• How could I have checked the Q45 for ball-joint & steering-linkage wear?
• How would I have accessed the front wheel bearings for greasing?
• How would I have accessed the ball joints for greasing?

[tangalora]

If you can answer those red questions above, I can better advise folks in an article.

Also, I forgot to note brake fluid replacement (which will occur after I do the rear wheels) & tire rotating suggestions (which I'll save for the articles so please post any helpful suggestions on those two necessary tasks too).

In the article that I hope to write, I'll also list the tools required and the parts required in separate sections.

Here, for the record, is a shot of 1/2 the front hardware kit from Joe at EVERYTHINGNISSAN lined up with the (old) parts that were being replaced.

[DAEDALUS]

Questions (considering my steering wheel wobbles slightly, at speed):

• Should I have greased the shiny steel canyon-clips (pad retainers)?
• Did I miss anything that needed to be greased (I had plenty left over)?
• How could I have checked the Q45 for wheel bearing wear?
• How could I have checked the Q45 for ball-joint & steering-linkage wear?
• How would I have accessed the front wheel bearings for greasing?
• How would I have accessed the ball joints for greasing?

1) Yes2) Pins and clips (and seals, if you do them too)3) You checked the runout4) Looseness between arm and knuckle5) Bearings are not serviceable--they're sealed, press-fit, and about $50 each for fronts6) Ball joints are not serviceable--also sealed and press-fit.6)

[maxnix]

The Q uses a greater percentage of rear brakes than any other FWD car.......why the faster wear and more warage on the rear.

While this statement is certainly true with repect to FWD cars, I assume you meant to say RWD cars since the Q45 is one such example.

Right?

Good write-up, Tangalora.

[tangalora]

While the parts list for a front & rear brake job has been noted in this thread; and while the score or so of R&R steps have been described, I haven't yet posted the tool list ... so ... here is my tangalora-recommended tool list:

• 12 mm box or open-end wrench (plus 12mm socket for torque wrench)
• 17 mm box or open-end wrench (plus 17mm socket for torque wrench)
• 2 inch micrometer (1 inch will work)
• dial-gauge with vise-grip flex-arm jig
• 12 inch pry bar
• torque wrench (up to 60 pound feet)
• disc brake spreader (preferably with two bolts; otherwise add a thin steel force-distribution plate)
• two cotton swabs (denuded of cotton)
• a dime & a felt-tip pen (to check scoring depth)
• 2-ton floor jack, chocks, & adjustable jack stands
• BBS hubcap remover (BBS wheels only)
• Rubber mallet
• 13/16 inch lug nut wrench
• 13/16 inch socket (for torque wrench)
• two 12mm x 1.25mm/mm flat-ended (not tapered) steel nuts (optional)
• shop towel
• 2 large 12 inch tie wraps or steel wire (coat hanger gauge)
• chalk (for marking tires, wheels, pads)

[tangalora]

As jobs go, there were few expendable supplies (besides GoJo & brake fluid). The grease came with Joe's hardware kit.

But, here are some tangalora special hints for you which I learned in the process of doing the brake job

• From my medicine chest
• (cotton swabs, denuded, to carefully apply the brake grease)
• From the kid's playroom
• (chalk to mark tires, lug bolts, rotors, & pads)
• From the kitchen shelves
• (the parts bin, i.e., a large red salad bowl)
• From the batchroom cabinet
• (the TP wrapper makes the most excellent & finest #5000 grit strong paper you can imagine)

Note of the tangalora hints above, it's the toilet-paper wrapper which is useful; not the TP itself (which is too soft to polish the nickel-coated steel caliper pins before greasing).