Diagnose my brake problem

[CREEP]

Okay, so since i've picked my car up over a year ago the rear brakes have been haunting me terribly. However, this i've learned has been a problem WELL before I was the owner. Since i've owned it alone it has been through 2 different sets of calipers, two different sets of rotors, and more sets of pads than i'd like to admit.

Ok, the inside of my LR rotor is consistently trashed by the pad. The outside however seems to be fine. The pads wear unevenly, as if the rotor is not sitting flush against the hub...but it is.

Now..the RR rotor is barely used.....barreellyy used. You can look at the outside of it and tell right away. Of course the pads stay fat on that side of the car.

Numerous bleeding sessions, TOO MANYY pad swap's...I mean this is just destroying my cashflow. Right now I don't have the money or the time to get all new hardlines from the dealer. I guess I was just wondering if anyone else has been through this situation. Any specific questions for a possible diagnosis just lemme know....thanks guys.

 

[jtmcinder]

Sounds like the pins are seized to me.

- Jtoby

 

[CREEP]

Pins as in the two 12mm bolts that hold the caliper on? They come right out. The piston's are going in and out freely also.

 

[jasoncitrano]

try completly taking the rotor off thats having the problem and looking at the hub to see if its worn unevenly or if rust build up is causing it to seat lopsided...my friends rotors were so badly rusted to the hub we hit them for an hour at school, (i go to UTI), and they finally broke to pieces before coming off, i would use a wire brush to cleap up the hub.

 

[wret]

Sounds like you've already replaced the most likely culprit: the caliper. That would have been my first suggestion. Check for an obstructed brake line.

 

[CREEP]

I actually did take the rotor off today and looked at how it was sitting against the hub, and it's completely flush. However, it does "float" around until I put the wheel on, whereas the other side doesn't. I have made sure when I put the wheel on that it's still flush. Would it be any possibility that one side is screwing with the other? For example, one caliper is puttin too much pressure, so the other side is putting very little..or vice-versa? That still wouldn't have anything to do with the uneven wear. Now something I have done is i've grinded off the little "tabs" on the back of the pads because I previously had almost NO use in the rear brakes. Also, I forgot to mention the resevoir leaks slightly, the rubber on the inside of the lid is fubared....dunno it that's relative to just the rear brakes.

For the hell of it I will take em apart and use a wire brush on the hub like you recommended jason, but I do think it's something with the damned hardlines. I'm afraid to call the enemy to get an estimate on them.

 

[dont need 8]

Did you check the proportioning valve?

 

[CREEP]

Did you check the proportioning valve?

Your serious? I'm not aware of such a thing, but if there is that'd be great.

 

[jtmcinder]

I guess we need more information. ABS? Parking brake - do both sides work? etc.

- Jtoby

 

[Defiant]

Now something I have done is i've grinded off the little "tabs" on the back of the pads because I previously had almost NO use in the rear brakes.

You've taken off the lugs that keep the pistons from rotating? So they can just adjust themselves as hard against the disk as they care to?

You're over your head. It's time to cut your losses and give a shop the money to fix what's wrong, before your random attempts stuff your car in a ditch, or worse.

 

[CREEP]

No ABS and the parking brake works fine.

...thanks defiant, but I'm just looking to see if anyone else catches this thread who's had the same problem.

 

[TimG]

The proportioning valve: http://www.mckeone.net/vfaq/abs/images/abs2.jpg

I believe it regulates the amount of fluid to the back brakes.

 

[dont need 8]

Your serious? I'm not aware of such a thing, but if there is that'd be great.

Yup, serious. There was a TSB for it on the 95 AWDs:

96-35-001 JAN 96 Rear Disc Brake/Proportioning Valve - Revision

Anyway, if you follow the hardlines from the master cylinder or booster you should find it. On my 1997 RS it is on the firewall. It basically controls how much pressure goes to each brake, giving more to the front than the back typically. Not sure if that device is causing your problem or not, but could be.

 

[CREEP]

Guys...I do appreciate it! This is something I was obviously completely unaware of. I'll give it a check. I love this website.

 

[CREEP]

Wow, that's what that thing is..

 

[CREEP]

Before I let this drop to the bottom....I forgot to mention the outside pads are usually never on the rotor. I can reach down and push them back against it w/ my finger.

Does that tell anyone anything else besides the fact my car hates me..

 

[Omega]

Are you sure the parts you are buying are the right ones? Perhaps your car is a X model year and in reality it was built with Y parts... just a thought.

Take it to a shop, have then diagnose it. Then when they tell you the car is unsafe to drive and hand you a $1000 estimate, drive to the parts store and pick the bits up. They hate it, but it saves you a few penny's.

 

[dont need 8]

Before I let this drop to the bottom....I forgot to mention the outside pads are usually never on the rotor. I can reach down and push them back against it w/ my finger.

Does that tell anyone anything else besides the fact my car hates me..

From what I have been told by various mechanics, the inner pad will wear faster than the outer pad.

As far as them not touching the rotor at all on the outer pad I can't help ya. Who has bled them, you or a mechanic? Have you ever had the system completely flushed?

 

[ASHICK]

the two bolts that hold the caliper on may be fine but the pieces that they screw into are siezed.......... if you had to grind off the location tabs to install the caliper . once thepins are free and new pad and rotors installed or if you wanna be cheap just free the pins reinstall the caliper with the piston compressed and move it back and forth with your hand if it dont move repalce it !!!!!!!!!!!!!1

 

[Turbo Talon DL]

Blind shot in the dark maybe, wrong parts will do this, but are you using all the neccessary mounting hardware for the pads?, (shims, anti squeel ect.) if you wanna keep your rotors from rusting onto the hub, put some grease or just vaseline on it. water intrusion sux...

 

[samgvr4]

Your serious? I'm not aware of such a thing, but if there is that'd be great.

Good point, i was just about to suggest that.
Your car is a 90 GSX so i bet you have no ABS, anyways the proportioning valve went out on my 90 so i replaced it, kinda a PITA.
it cured the problem that i was having (similar to your)
now the RR caliper is starting to act up, so i will rebuild it.

Thanks

Sam
90 GSX

 

[Erok]

areu sure you dont have mounting bracket or caliper from a vented rear end, the vented rotors are wider and could be why your new pads arnt contacting on the non vented (thin) rotor, find known good (ie another car the same production date as yours and compare, u will find whats wrong im sure) known good is best way to diagnose anyproblem. give er' a try bud
erik