I want more stopping power!

[ottofalcon]

Well today i was driving down some mountain roads on the island and a couple of times I noticed some fade and that doesnt make me feel safe! My braking system is well maintained new disc, akebono pads, and wagner shoes. What sort of upgrades can I do to give me more stopping power?

[iceman14n]

cross drilled or slotted rotors with ceramic pads is most you can do...

[ottofalcon]

I have ceramic pads already, but it might try slotted rotors. Are there no bigger brake kits or something like that?

[Towncivilian]

Flush your brake fluid to reduce the chance of brake fade. Ethylene glycol based brake fluid (DOT3, DOT4, and DOT5.1) is hygroscopic, meaning it absorbs moisture from the atmosphere. This will reduce the boiling point of the fluid, which may result in brake fade (in which case the brake pedal falls to the floor and you have reduced or no braking) if the fluid boils. The moisure also can result in corrosion and reduced life of brake components. There is no recommended service interval in either the owner's manual or factory service manual; some other makes do specify intervals, however. It is generally recommended to flush your brake fluid every 2 years. Either DOT3, DOT4, or DOT5.1 brake fluid is usable. DOT4 has higher minimum wet/dry boiling points, and DOT5.1 has higher boiling points still. Never use DOT5 in a system designed for ethylene glycol based brake fluids as DOT5 is silicone and does not mix with the other DOT types.

If you have a 4WD Pathfinder, be sure to bleed the load sensing valve (instructions under the "Brakes" Q&A section in the general information thread). Also make sure your rear drums are in adjustment.

[ottofalcon]

Im going to try that this weekend then, i have a qx is there a special method of bleeding an abs system?

[Towncivilian]

No. The FSM does not state anything regarding the ABS system. All necessary information regarding bleeding order and instructions for bleeding the LSV is in the general information thread I linked. I'd go with DOT4 fluid, since DOT5.1 is rather difficult to find. You can get this quart of Valvoline DOT4 brake fluid from Advanced Auto Parts for $6.79 before tax if you order online and use discount code P15 and pick-up in store. I use this fluid in my Pathfinder, works just fine.

[ottofalcon]

Yeah I work at advance I'll get some and give this a try this weekend. Also it unrelated but my gas milage the past two weeks has been horrible!

[Towncivilian]

Probably related to winter blend gas. Make sure your air filter isn't ridiculously dirty if you haven't yet. How many miles are on your QX4?

[ottofalcon]

Well I live in Puerto Rico so winter Here is like summer for some states 80f avg. I have a k&n and it's clean, and last week i rolled up on 140k, I change my oil once it starts to get dirty, I use Mobil1 Extended Performance. No CEL and she runs great, I have tried using 93 and 87 and a tank might last 160 to 180 miles no better than that. I drive mostly city but no hard acceleration and yea a/c is always on.

[Towncivilian]

The color of the engine oil means nothing unless it's milky, which would indicate coolant present in the oil. How long is your typical oil change interval?

Don't clean your air filter too often, otherwise it will leave an oily film on your MAF sensor and potentially let more contaminants through. Filtration actually improves as it collects dirt. Follow K&N's recommendation:

4. How often do I need to clean my K&N air filter?

If you have not experienced a decrease in mileage or engine performance, chances are your filter is fine and does not yet need cleaning. To be more specific, the filter does not require cleaning if you can still see the wire screen on the entire air filter regardless of how dirty it may appear. When the screen is no longer visible some place on the filter, it is time to clean it. When used in normal paved road, street or highway conditions, our replacement air filters that fit in the factory air box should require cleaning every 50,000 miles and our large conical filters on an intake system should require cleaning every 100,000 miles. When used in dusty or off-road environments, our filters will require cleaning more often. We recommend that you visually inspect your filter once every 25,000 miles to determine if the screen is still visible.

What is your tire pressure set at?

The spark plug change interval is 30k miles. Were they replaced around 120k? If not, replace them with 6 of NGK 6953 plugs. Run some Chevron Techron fuel system cleaner through one full tank of gas, too.

Never run anything higher than 87 octane in your QX4 again, the engine is designed to run on regular (87) octane and anything higher will not result in any gains whatsoever.

[Alfredo24.pr]

I have ceramic pads already, but it might try slotted rotors. Are there no bigger brake kits or something like that?

Im checking to see if brembo brakes from a 350z/g35 fits my pathfinder, but it will be expensive and with custom fitment if possible.
check for EBC 3GD Sport rotors on ebay for the front brakes. (they are drilled and slotted)

[ottofalcon]

The color of the engine oil means nothing unless it's milky, which would indicate coolant present in the oil. How long is your typical oil change interval?

Don't clean your air filter too often, otherwise it will leave an oily film on your MAF sensor and potentially let more contaminants through. Filtration actually improves as it collects dirt. Follow K&N's recommendation:

4. How often do I need to clean my K&N air filter?

If you have not experienced a decrease in mileage or engine performance, chances are your filter is fine and does not yet need cleaning. To be more specific, the filter does not require cleaning if you can still see the wire screen on the entire air filter regardless of how dirty it may appear. When the screen is no longer visible some place on the filter, it is time to clean it. When used in normal paved road, street or highway conditions, our replacement air filters that fit in the factory air box should require cleaning every 50,000 miles and our large conical filters on an intake system should require cleaning every 100,000 miles. When used in dusty or off-road environments, our filters will require cleaning more often. We recommend that you visually inspect your filter once every 25,000 miles to determine if the screen is still visible.

What is your tire pressure set at?

The spark plug change interval is 30k miles. Were they replaced around 120k? If not, replace them with 6 of NGK 6953 plugs. Run some Chevron Techron fuel system cleaner through one full tank of gas, too.

Never run anything higher than 87 octane in your QX4 again, the engine is designed to run on regular (87) octane and anything higher will not result in any gains whatsoever.

Well I just bought the air filter, I haven't cleaned it yet. The oil I change it about 4500-5000, that's when it usually starts getting a bit dirty. I always use Mobil1 EP 5-w30

Tire pressure I haven't checked, I just bought new tires a couple of months ago so it should be 32psi or something like that. What pressure should it be at?

I changed the spark plugs at 140k with the ones the owner's manual says to use. NGK I believe.

Last 3 fill ups I used Regular 87, I'm going to run the techron and change the fuel filter to see if that improves.

The funny thing is that i bought it with 132k or so, and fuel economy was better around 180 miles on a tank. But the last couple of weeks have been horrible!

[ottofalcon]

I have ceramic pads already, but it might try slotted rotors. Are there no bigger brake kits or something like that?

Im checking to see if brembo brakes from a 350z/g35 fits my pathfinder, but it will be expensive and with custom fitment if possible.
check for EBC 3GD Sport rotors on ebay for the front brakes. (they are drilled and slotted)

Ok, I'll check that out! Hey btw your from P.R. right?

[Towncivilian]

You are wasting your money running M1 EP for 5000 mile OCIs. It is capable of 7500+ miles, though anything past 10,000 I'd get a used oil analysis with TBN (total base number; a measurement of the active additive left) to be sure. Just because it starts to get dark doesn't mean it's dirty to the point of unusability. Oxidation, blow-by gases, heat, and deposits suspended in the oil all cause the color change, but that doesn't mean the oil has no active additive left to deal with the operating conditions of an engine. If you wish to stay with shorter oil change intervals, switch to a name-brand conventional such as Pennzoil Yellow Bottle (which is arguably the "best bang for the buck" conventional oil today, after looking at a virgin oil analysis of it) or a heavy duty engine oil such as Rotella T 10W-30. What oil filter do you typically use?

I run 32 PSI in my tires. Perhaps try reducing the pressure to whatever the door jamb sticker says.

[ottofalcon]

I know my oil changes are to short but the thing is that my engine has a bit of sludge and I'm trying to clean it out, and I get a 35% discount on everything I buy in Advance so it isnt that much money. I was using K&N oil filter but i switched to the Bosch filter. What do you recommend in place of the shorter oil changes. I prefer using synthetic, I have a 1991 Montero and since it was new my dad used synthetic oils and that engine with over 232k is in better shape than my qx's, no lifter tick (plagues all mitsu engines) so maybe it's excessive maintenance but i kinda makes me feel better that the oil is a higher quality =D

[miamiheat3332]

Im very interested in a big brake kit if anyone can find one or if we can retrofit one. I'll be needing to do mine later this year, even though my rotors are in great condition, i would still do a bbk.

BTW - I have ebc 3gd slotted and dimpled rotors for the past 4 maybe oncoming 5 years now, and they are in great condition. Well worth the money, i also have ceramic pads with them but i cant recall what kind they were.

[Towncivilian]

K&N filters are exactly the same as Mobil 1 filters except K&Ns have the welded nut at the bottom. Use M1 filters instead of K&N if you choose to use them again in the future.

By "Bosch" filters I assume you mean Bosch Distance+? Those are excellently built and can easily go 15k miles. If you're trying to clean out sludge, just use a conventional oil and do several 3,000 mile oil changes using Pennzoil Yellow Bottle (it contains a lot of detergents compared to other conventional oils) and Purolator PureONE filters, then switch to synthetic afterwards.

[m0nkeyprince]

since your disks are new, just switch your pads to hawk LTS, theyll give you HPS type stopping power.

do NOT get drilled discs, they only reduce the structure strength and ive seen too many of them crack. The most you should go is slotted or dimpled like on the higher end EBC disks.

I myself have EBC slotted rotors with Hawk LTS pads and they stop like a dream. If those dont work, you probably have to bleed brakes (dont forget to bleed the Load sensing valve too)

and Town Civilian, its nice to see that you became a mod, I havnt been keeping up with nico n npora for a while so it was a surprise.

[CanuckQx4]

The funny thing is that i bought it with 132k or so, and fuel economy was better around 180 miles on a tank. But the last couple of weeks have been horrible!

You only get 180 miles to a tank and thats your BETTER mileage??

I get 250-260 a tank and I only city drive

[CanuckQx4]

And there has got to be a brake/rotor/caliper from another car that would somehow work with our cars to make a big brake setup

Maybe we should look at cars with the same bolt patterns as us??

6 x 139.7 metric or 6 X 5.5

Take a look at this spec sheet I found with cars sharing the same bolt pattern as us. Even lists bore size and hub specs.

http://www.roadkillcustoms.com/hot-rods ... udSpreadMM

[CanuckQx4]

Id rather have rear disksthat a front brake size upgrade though.

Drums stink I like rotors

[ottofalcon]

K&N filters are exactly the same as Mobil 1 filters except K&Ns have the welded nut at the bottom. Use M1 filters instead of K&N if you choose to use them again in the future.

By "Bosch" filters I assume you mean Bosch Distance+? Those are excellently built and can easily go 15k miles. If you're trying to clean out sludge, just use a conventional oil and do several 3,000 mile oil changes using Pennzoil Yellow Bottle (it contains a lot of detergents compared to other conventional oils) and Purolator PureONE filters, then switch to synthetic afterwards.

Exactly I use Distance Plus, Well my next oil change isnt coming up in a while but I'll follow your advice once it does.

since your disks are new, just switch your pads to hawk LTS, theyll give you HPS type stopping power.

do NOT get drilled discs, they only reduce the structure strength and ive seen too many of them crack. The most you should go is slotted or dimpled like on the higher end EBC disks.

I myself have EBC slotted rotors with Hawk LTS pads and they stop like a dream. If those dont work, you probably have to bleed brakes (dont forget to bleed the Load sensing valve too)

and Town Civilian, its nice to see that you became a mod, I havnt been keeping up with nico n npora for a while so it was a surprise.

Compared to the OEM disc is there a big difference with the slotted?

only get 180 miles to a tank and thats your BETTER mileage??

I get 250-260 a tank and I only city drive

Yeah that's my best mileage, never been higher than 180, right now I'm at half a tank and I've driven exactly 73 miles!

[Alfredo24.pr]

Ok, I'll check that out! Hey btw your from P.R. right?

yes

Yeah that's my best mileage, never been higher than 180, right now I'm at half a tank and I've driven exactly 73 miles!

wow but that must be because of the city traffic, because on highway trips I only take a bit more than 1/4 from San Juan to Mayaguez (a 105 mile trip)

[m0nkeyprince]

well slotted is supposed to evacuate "gas" that gets created when the pad touch the disk but thats only really a problem on older pads, now slotted is more for looks than anything else for street. what would probably make a difference though is disc cooling, every disc uses conventional vane cooling, but disc brake australia has really cool discs that uses a difference cooling architecture "kangaroo paw". i wouldve gotten it but they dont make discs for 98 pathys or qx4s

[ARKQX33V6]

Canuck, how can you Drums suck? If you maintain them, they last, they don't fade, they don't rub constantly, they are simple to clean, and adjust. With my QX4 they lasted 15 years. With the front doing most of the stopping the best I could get is 100,000 km from a set of pads and that was with 3 sets and with original disks

Front brakes need cleaning every 3 months and lubrication of the cylinder and rubbing areas.

On the rear a cleaning twice a year and maintenance on the e brake and keep the cable lubed and adjusted.

[CanuckQx4]

I dont understand drums, nor can I service them myself. And I just plain dont like the look of them

I change my brakes probably way more than necessary anyways, and like doing it myself. So id prefer a rotor in the back

Would make my damn day

[ottofalcon]

Checking in here!

On thursday I was at the shop where I take my truck and they had a qx4 there and I got to talking with the owner and I told him about my s*** gas millage and he told me that he had the same problem and it turns out it was a clogged cat. So I asked if they could check mine out and voila both cats where plugged!

I told em to delete the cats and fix my leaking muffler, 150.00 parts and labor. I filled the Qx up on friday and 156 miles later and I'm at half a tank! The difference is huge the car feels more responsive, smells a bit but sounds great!

[miamiheat3332]

No CEL?

[ottofalcon]

Yeah i got the cell about 3 or 4 after the cats where removed, but I just removed the light from the socket.

[Towncivilian]

I hope you pull codes monthly or so to ensure that no new codes pop up.