ESMsilver00SS

iTrader: (3)

To make a long story short, I have had some issues with my brake system and have been unable to pinpoint the problem.

I have relpaced rotors, pads and flushed the system completely twice. The first flush there was air in both rear lines, the second time there was only air in the right rear. No air was in the front lines at all.

The issues I am still having are spongy pedal/loss of braking force after steady braking from 70mph + and the car pulls to the left under moderate braking.

Normal driving at slower speeds the car brakes fine, it's really noticable braking at high speeds under moderate to high braking, every time.

There are no leaks or puddles that can be found, used a pressure bleeder to bleed the system and the pressure held. So if anyone has any ideas on what could be wrong I would greatly appreciate it. Thanks.


I am posting this in different forums to better my chances of finding the problem.

JD_AMG

What kind of pads do you have?
As far as the car pulling to the left, you probably need an alignment done.

ESMsilver00SS

iTrader: (3)

pads are Carbotech Bobcats and the car only pulls to the left under braking

DaddySS

What problem were you trying to solve when you replaced all the items, the same one?

Spongy and pulling would seem to indicate that one of you calipers is not working right, in this case the right side. Did you have the calipers off or did you just leave them connected and replace the other stuff. How did you compress the calipers? Did both sides move smoothly?

Tainted

iTrader: (9)

Id put money on your caliper pistons are fucked up

ESMsilver00SS

iTrader: (3)

yes, I replaced the other parts to try to solve the same problem. I did screw up the previous time I installed pads and the right front pad did not move smoothly in the caliper, but I installed it anyway because I didn't think about it at the time. Could that have messed up the caliper? I made sure they moved smoothly this time.

Left the calipers connected, never taken them completely off. Compressed the calipers with a large C-clamp while they were on the car.

So do you think I broke my right front caliper? I am only getting air in the rear lines and not the front. So do I possibly have a bad right front caliper and a bad master cylinder letting air in the rear brakes?

Thanks for the help by the way.

Roadhouse

iTrader: (8)

*Just a guess here*... If both calipers are in working order try replacing the right front passenger side flexible brake line to that caliper. It may have collapsed internally causing a delay of fluid to that caliper, which would cause your car to go left under braking.

2002 SS #476

iTrader: (2)

If you want to check your calipers a quick is to go out and do some hard braking. Do enough high speed stops to heat the rotors up, get out of the car and check all the calipers with an infrared thermometer. If one caliper is a lot cooler than the others you know you have a problem with that brake. Sometimes the pressure bleeders don’t always do the best of jobs(try manually bleeding the system), on a manual tranny start with RR, then go to the RF, then LR, and last the LF, it’s different on an automatic transmission ( I’ll look what order it is for the autos. and double check for the manual to make sure I’m right). Following the correct order will keep you on the same brake line, sometimes if you don’t go in order and swap lines the air can be pushed around in the system. Always make sure you put moly lube on the pins for the calipers.

ESMsilver00SS

iTrader: (3)

So do you guys think the next step for me should be to grease the guide pins and possibly rebuild the calipers.

http://www.installuniversity.com/ins...er_rebuild.htm

I also thought maybe I was getting air from where the brake hoses connected to the calipers, there is no fluid leaking out, but the hose looks like it might have fluid on the hose from where it connects to the caliper. The hoses have never been removed and the car does have 104k miles on it.

Also if I have a 'bad' caliper, will rebuilding them fix the problem?

How can I find where I am getting air in the system?

thunderdan74

iTrader: (1)

If you didn't lube the giude pins that can cause it. Mine were siezed so bad that only my rear brakes were stopping the car. I had to replace one caliper bracket when I broke a pin off in it trying to pull it out. It was $120 worth of 20/20 Hind sight!

2002 SS #476

iTrader: (2)

What kind of wheels and exhaust tips do you have on your car?

thunderdan74

iTrader: (1)

Wheels are Sport max 962. And it's Corsa catback with 4" pro series tips.

ESMsilver00SS

iTrader: (3)

Dropped off the car at the dealer this morning, didn't want to start replacing parts not knowing what the problem was.

They just called me and said that there is definately something wrong with the brake system, but there was no air in the system. He said they don't know what could be wrong yet and he would get back to me.

I hope they figure it out, sucks trying to stop from 100mph +.

ESMsilver00SS

iTrader: (3)

The dealer cannot find anything wrong with my brake system but does acknowledge that there is a problem with the brakes fading at high speeds.

He said they are stumped and everything from the calipers, abs module and the master cylinder are working as they should. The only thing they can think is wrong is the pads.

This problem has happened with both Hawk HPS pads and Carbotech Bobcats. Same problem, two different pads that can handle more heat.

This sucks.

ls1builder

what about a shock problem on the left at slower speeds theres not as much weigh transfer to teh front at hight speeds maybe u have a left front shock issue but this still wouldn't explain the spongy pedal unless your pads are building up to much heat and bulling the brake fluid are u using stock rotors with thoses pads may need to get a biger rotor to disapate the heat just a few hits i got hope there helpful

ESMsilver00SS

iTrader: (3)

I don't think it's the shock, they are Bilsteins and the car only pulls to the left under braking. Also, the rotors are Brembo blanks, stock size. I am convinced that the pads are not the issue since the fading occured with both Hawk HPS pads and Carbotech pads.

Next weekend I am going to grease all the guide pins, and check for air in the lines again.

Since I got the car back from the dealer, it seems a little better, I think because they cylcled the fluid thru the abs module.

If I still have problems, I'm going to try putting in new lines.

Sharpe

iTrader: (7)

Don't ask me to explain this, but I've been told in person by a couple different people that pulling when braking has nothing to do with anything but the alignment. Not saying that's true, not saying I know why. My car drives straight at all speeds but sometimes pulls a bit when braking.

What about vaccume?

I'm a total noob, just asking.

ESMsilver00SS

iTrader: (3)

My car is the same way, drives straight, just pulls a little while braking. By vaccum, do you mean the brake bias? I've thought about that being the problem as well.

juicedls1

iTrader: (9)

My first guess would be a bad brake line (rubber) if the inside fails then it would cause a fluid restricion which in turn would make a car pull during braking and or a spongy pedal, then my second guess would be the master cylinder not giving good pressure under a hard brake! (lets say ur car is pulling to the left then thatll mean the right side brake line is bad cause the left is working and the right dont have the right pressure to work the brake caliper) HOPE THIS HELPS!!!

ESMsilver00SS

iTrader: (3)

Good point, thanks. I think after I grease all the guide pins, if I still have problems, I will change all the lines as well. The car does have 105k miles, so upgrading to stainless lines couldn't hurt.

The dealer said that the master cylinder was ok, I hope they're right.