Brake problem?

[Q45Viper]

92 Q, federal model, traction, 130k, original owner. Here's the question, car was at the dealer one month ago for a variety of stuff that included check of all brakes and subsequent replacement of front pads and turning of the rotors, I really knew I needed the rotors done when I went in. Anyone who has put 130k on one of these can feel it coming. The rears were pronounced OK by the dealer, lot's of wear left. Now to the problem, upon exiting the car I have noticed a lot of heat and an odor coming from the left (driver side) rear wheel, I am also noticing a lot of brake dust buildup on that wheel that would really be more characteristic of a front wheel, tonight I walked around and tried to compare wheel temps. by touching each wheel both on the rim and the center section (BBS RZ 15 inch) All the wheels were hot but I could put my hand on the other three and keep it there, the drivers side left rear really too hot to hold your hand on it, also this funny smell, which previously I had attributed to the brand new front pads bedding in. Also the car is making a small groaning noise as the brakes are released from a standstill. This noise did not bother me too much as I have heard something like it before and it was attributed to a loose exhaust shield, once fixed and it was fine. However I do not remember it occuring as brakes were released. Only at idle. My stupid uneducated guess would be my emergency brake is hanging up. Help guys! What is this? The car drives out fine but this doesn't seem right. And I have become convinced of Q45 tech's strategy...fix it BEFORE it breaks...now what is it?Edit...Oh, geez, I just had a worse thought...wheel bearing?

[DAEDALUS]

E-brake is my first guess too. Pull the rotor and poke around a little. Look and feel for things that aren't in the right place, and for excessive wear. I would think something like that would generate enough clues for you to diagnose at home.

[Q45Viper]

Thanks for the reply, there is an interesting timing issue here as this started the same time the dealer pulled all four wheels and delared the rears Ok but the fronts needed pads and rotors turned. I like and respect this dealer and I'm not looking to make trouble for them but I'm wondering what might have happened when they did that that might have started this, seems like a heck of a coincidence. Anyone have any thoughts as to what happens during a routine brake inspection that might lead to this problem?

[ucfz31s13]

Here's my take on it...If they did a 'routine' inspections, then they only 'inspected'. This means they shouldn't have really touched or toyed w/ anything that would have a bearing on the problems you are describing. Only thing they 'might' have touched if they removed the caliper is the e-brake cable, but then again you can check the pads and mic the rotor w/o removing the calipers, so my guess is they didn't. My guess is it's a coincedence. A few possible things that could be contributing to your problem are as follows.

-Misadjusted E-brake cable-Bad proportional valve-Frozen/stuck calipers-Bad master cylinder-Clogged brake lines.

The first is easy to check...Remove the wheel and let the e-brake down and see how much tension is on the e-brake line going to that caliper, shouldn't be too tight (when they are mis-adjusted the line going to that side caliper is engaged when the e-brake is released).The 2nd and 3rd are rather hard to pinpoint between them, as they both have very similar symptoms. The proportional valve is under the master cylinder and distributes the fluid beteen the front and rear. The front should be 2 individual lines, and the rear 'might' be just one (not sure on your Q45). I know my z31 has just one line, and when my proportional valve went out, BOTH rear calipers were locking up. Since you say that only one side caliper is grabbing, that might help narrow it down to a frozen/stuck/bad caliper. Not really a sure-fire way to test that besides replace it/get a rebuild kit.Bad mastercylinder or clogged brake lines can cause it, but not likely. Usually when the mastercylinder goes you lose brake pressure, not gain it.I vote on the frozen/stuck/bad caliper idea.

And that noise you hear might be that caliper groaning once you start moving because it's tight on the rotor. All those smells you mention and the heat you feel on the rim are all signs of a brake freezing somewhere...probably just that one caliper.

Hope the info helps, Good luck!

lataz

z

[Q45Viper]

Some more information, I don't think I've ever flushed or replaced brake fluid, and I don't think the master cylinder has been replaced, the car brakes super, no problem. I agree a caliper is hung up or, proportioning valve is stuck or ebrake. Now is the abs system 3 way or 4 way and could one valve to that wheel only be inoperative? How would the ebrake suddenly be out of adjustment and hang up? How does a caliper suddenly start to hang up, especially if it was just examined anf finally, any danger here as far as getting stranded, I just can't get the time to get to this untill the weekend or next week. Thanks guys.

[ucfz31s13]

Brake fluid should probably be flushed sometime soon when you get the chance. Not really a bid deal now, you've got 130k miles, another 1k won't hurt. But you'd be surprised how much trash accumulates in the master cylinder when you don't flush the fluid after X amount of years. Not sure about the 3 or 4 way ABS question. My best guess would be to look at the master cylinder and see how many lines you got going where, etc...The e-brake wouldn't suddenly just 'get out of adj' or 'hang-up'. Thats why I kinda ruled that one out, unless the mechanics at infiniti touched it for some reason, but thats not likely. Calipers/Mastercylinders/Proportional Valves/etc all just deteriorate over time. Same things goes for most of the parts on the car. You park the car at night, go out in the morning and you find the Crank Angle Sensor wen't bad. Why did it happen, like in this case w/ maybe that same thing happening to your caliper? Who knows. The brake equipment has so many seals and rubber parts that one might've just decided to go kaput, or maybe something internal in the caliper went bad...it's hard to say, but once you get up in mileage things like that happen over time.No real danger of getting stranded, unless the caliper just SEIZES on you. Then you could still probably make it to your destination but that rotor will be glowing red and that caliper would be crap (as it was anyways if this is problem), and you'd probably need new brake pads, etc...If you have a manual transmission, try going around the block and only stop by pulling the e-brake. See if the rim still gets hot and if you still hear that groaning/moaning sound you were talking about. By braking only w/ the e-brake you wont be using the brake hydraulic system and can see if the groaning has something to do w/ the brake stuff or not..

lataz

z

[DAEDALUS]

Great suggestion. Maybe hold the release handle out so you can get some feedback through the ebrake pedal.

[ucfz31s13]

I had to do that back and forth through town on my way to work for like a week. My proportional valve took a dump and both front (not rears, sorry) calipers would lock/sieze up viscously at the touch of the brake pedal. Had to use the e-brake for all of my braking period. Couldn't stop for the love of god if my life depended upon it.

I remember when the problem first occurred, they seized up in the rain after braking fully at a stoplight. I tried going and it looked like I was powerbreaking the friggin' thing. Ended up in 2nd gear at like 3k before the car decided to start rolling. Gotta love turbo's

lataz

z

[Q45Viper]

Update....I think I did the wrong thing, I decided to wait and see what happened. The noise seemed to go away, how could it be brake related if it faded or went away, right? My bad! Suddenly without warning, I have a noise that sounds like two terminators rubbing metal on metal, do I have a brake problem, Oh yea! Now I've already been on the cell with my two favorite private mechanics and my dealer as I weaved my way home through traffic, timing the lights to avoid hitting the brakes, that first gear can REALLY slow ya down! 6:30pm dealer not closed, but all service advisors gone, need my buddy who I helped find a great deal on a Vette a month ago, maybe if I turn this thing around I can get it down there without hitting the brakes and I'm back in a G35 with no worries, nope not gonna happen, he's gone for the night, I'll be with him on the phone around 7am. Now guys, is this a caliper hanging up if it's this terrible grinding noise when I apply the brakes? Seems more like a pad completely gone grinding on the rotor. If anyone could give me an opinion of this it would help, because these brakes were inspected 4 weeks ago by the dealer and "the rears are fine" new pads and rotors turned on the front. I do not think a hanging caliper would cause this terrible grinding noise on applying the brakes, it sounds as if the pad is gone working on the rotor, opinions please guys, if they missed this, I'm going to be polite but ask for some help $ wise. I mean after the guides and all the other stuff it's been about $5,000 the last couple months.

[DAEDALUS]

If the pad was worn down past the friction material, that would cause quite a bad grinding noise. Another sign of a sticking caliper, and would explain all the dust you've been seeing. I say don't drive the car. Honestly. If you're worn down that low, you might be at a serious risk of having the pistons pop out and losing all brake fluid pressure instantaneously. And the pistons are probably wearing on the caliper walls a lot more too.

[Q45Viper]

You Sir, win the prize! That's exactly what it is. Unbelievable! Car just came out of the dealer 4 weeks ago with new front pads and the rotors turned. My reguest was to check all four corners and R&R as needed. They came back with don't need any work on the rears. I can even guess why, the only rear they pulled was the OTHER side and then they ASSUMED both sides were the same. GRRRRRRR! The other side is still lookin' great, looks like 20k left, this side is through the pad with all the possible extra expense! I may be lucky though, when I first heard the noise, I managed to limp it in without hardly touching the brakes. The worst part is it's at my local guys shop who has really high pricing on brakes, twice what the dealer is, if you can believe that. And of course if there is extra damage I would kinda have the dealer at my advantage as the printout says the rears were fine, but it ain't drivable to get to the dealer all around the DC beltway, stop and go city and of course using a flatbed would eat up any difference, sigh...... Oh well, thanks for letting me vent guys.

[maxnix]

I would make it the dealer's flatbed. I think you have a legitimate gripe, and if the dealer won't cover you, it's time to call the local area service representative. FActory pads do not fail catastrophically.

Dealer's covet their 100% satisfication ratings.

[DAEDALUS]

Well it's a heck of a fluke, but I don't think there's any way to prove negligence on the original inspection IF the service records state they ONLY checked the pads. If there's any indication they checked or were supposed to check the calipers too, then you have a valid case. It's easy to check pad thickness visually. It's a different thing to check shear pins, lubrication, and proper unbound movement. But if that's what they were SUPPOSED to do then you should let them know, and give them the option of either towing the car there for repair or covering your bill at the other shop. Sounds like it's a little late for that, but keep it in mind. One thing you might try is to call up or go in, like a guy off the street, and ask them what brake services they offer. The goal is to get them to call it exactly what's stated on your invoice. Then ask them what that includes. Try to get them to state that it includes a thorough checking of the calipers. Get it all on tape, and if they say the service is comprehensive, pull out your invoices (theirs and the other shops) and tell them you think they should pay for the 2nd service.

[Q45tech]

Visual check is all you get unless you pay for a measurement or brake R&R............check the brakes means to see if they are there more or less.

[Q45Viper]

Well for what it's worth what I asked for was to have them pull all 4 wheels and repair and replace any brake components neccessary, to include replacing pads, turning or replacing rotors as needed, they responded by saying, we've checked all four corners the rears are fine you have lots of wear left in the rears, and they actually quoted me the measurement left and the miles left, don't remember the measurement but do remember 10k miles left. you do need front pads and the rotors turned they said. The most amazing thing is you don't even need to pull the wheels to see the problem, I have one very new looking blue colored pad visible through the spokes of the BBS wheel and on the other side a completely chewedup beat to sh$t looking rusted pad with metal dragging on the other side, this is 3-4 weeks later, demonstrated to me today by my local mechanic I trust. I also trust the dealer, they did a great job on my chain guides, I would recommend them to anyone, I think this is just one of those things, someone did not do the inspection they were asked to do. I guess I'm a strange guy, I believe people can make mistakes, I will suffer through this, wait till I calm down, let my service advisor know what happened, quietly, calmly, and see what I can get out of it in the future, I'm not gonna blow a relationship where I'm not only getting a loaner but the guy makes sure I get a G35 instead of an I35. Stuff happens and you have to understand people make mistakes, now having said that is it not amazing that that they could have charged me for all fourcorners, I mean I said on the order do all four as neccessay, I'm thinking maybe something else happened that may be determined to be the cause. I always hope for the best and I trust my gut when dealing with people who work on the car, I am waiting for my trust to be validated, film at 11:00pm on thursday. And thank you guys for your advice and support.

[Q451990]

I will suffer through this, wait till I calm down, let my service advisor know what happened, quietly, calmly, and see what I can get out of it in the future, I'm not gonna blow a relationship where I'm not only getting a loaner but the guy makes sure I get a G35 instead of an I35. Stuff happens and you have to understand people make mistakes...

You're the type of customer everyone wants! I'd sure ask about it, but I bet they'd say the caliper must have frozen later - causing rapid brake wear.

Heath

[Q45Viper]

Final update, best assumption, caliper froze without warning, required new rotors, calipers and pads on both rears, probably no ones fault, just a coincidence, put it on the list of preventative stuff to do if you've got 130k! I mean how long can you expect calipers to last? Although I really can't remember, nor do my records tell me if they are original, I think this is the second time around. But hey, the DC beltway, serious brake wear!

[Q45tech]

All my calipers are as built in 1/90 but I flush the brake system every year at minimum........252,000 miles but I still get pin seizing problems and try to change the pads often but the rotors are always off every 6-7,000 miles for retrueing.