Nastyc4

iTrader: (13)

Have had a problem for a while. Here's a brief history:

First thing I noticed is when bought the car the rubber boot inside the master was so swollen I couldnt put it back in when I was checking fluid. Replaced it and same thing happened to the new one.

At speed when braking first symptoms were the car would brake normally an then halfway to stopping the pedal would sink 1 inch and get firm and what felt like serious brake fade. The pedal would be firm and sometimes still stutter like abs was going on. I had to stand on it with all my might a few times to stop.

I haven't changed the pads but I did try bleeding all the brakes to see if there was any air in the system. Didn't help.

Now, even slowing to a slow stop (from 20mph) the car stops ok but sometimes the pedal will sink 2 inches and I have to be careful I don't roll into the guy stopped ahead of me.

Because it's winter now and the brakes are cold I'm guessing it can't be fade from overheating. Someone mentioned contamination of the fluid because of the way the rubber boot swells, I am planning a flush soon. Coil this be the brake booster? What are symptoms of one going bad? I do have longtubes and I heard heat from them can kill boosters.

Any thoughts are appreciated!

sjsingle1

iTrader: (1)

bleed.......bleed...............bleed again.........or you have leaky caliper pistons or a shot master cylinder

RedHotG8

iTrader: (1)

If you have ABS the ABS module has the be cycled with a Tech 2 while bleeding the brakes or you'll never get all the air out of the brake system.

ShortChevy

iTrader: (21)

^^^This, also disregard the headers killing boosters comment. That is highly unlikely. If a bosster goes then it was prolly just time. Flushing the fluid and using a Tech 2 is the way to go, If one isn't available then go to the dealer.

Nastyc4

iTrader: (13)

Fluid is still topped up I cant see it leaking causing pedal to sink.

I guess I should flush it. it's the only thing that can explain the rubber in the master swelling up so large it wont fit back in. maybe the previous owner put the wrong stuff in there.

RedHotG8

iTrader: (1)

Didn't you comprehend what we said about the ABS cycling with the Tech 2? It has nothing to do with the type of fluid that's in the system.

Nastyc4

iTrader: (13)

I did indeed I have figure out how I can do to get someone with a tech2 to do this. Would a performance shop be able to do this? I may just have them do a complete flush and bleed.

Just don't tell me I have to go to a dealer, I'd rather sell my car as is.

ShortChevy

iTrader: (21)

Tech 2's are pretty much a GM dealership tool. There are many scanners and software programs out there but nothing is exactly like a Tech 2. If you find a shop that has one that isn't a dealership they most likely bought it used from a closed down GM dealership.

wrencher

iTrader: (2)

Search brake bleeding. A Tech II or other capable scan tool is not a must to bleed the brakes. It just makes it quicker & simpler.
Example is I can prolly bleed an entire car out in less than 10 minutes w/a power bleeder & a Tech-II.

But if your stuck doing it manually you can.
As long as the ABS EHCU is functional your good to go.
Worst case scenario;
You have to bleed it once, put it together & drive it. Slow drive needed 15+ mph or so.
Then rebleed it.
The ABS system will do a cycle & re-home on the dump/hold valves in the EHCU during the test drive as a self test.
If any air was caught in the EHCU you can now bleed it out on the second bleed session.

As for your master's reservoir boot going bad & expanding twice;
You need to flush all the fluid out of there. It sounds like a fluid contamination issue.

NBM99SS

iTrader: (33)

If your seal inside the master was swollen the fluid was contaminated. 99% of the time that means you need new master cylinder and possibly hoses and all 4 calipers depending how bad it was. Plain and simple.