Brakes Failed

[Billy Mild]

The brakes on the corvette failed today. I was coming to a stoplight, the car was slowing down when I pressed the brake pedal a little harder to come to a stop faster. At that time I heard a pop and the brake pedal went all the way to the floor. The car continued to roll forward and would not slow down.

When I lift my foot off the brake the pedal came back to the normal position. I was able to pump the brakes, but they had 0 resistance. The brakes are not effective. Also my BRAKE light is lit up in the gauge cluster all the time now. I haven't torn into the brakes yet, but Brake Fluid reserviors are both full, and I don't see any leaking fluid around the front brake calipers.

I don't really know what to start with if I should look at the pads, or something more serious. Any ideas?

[Dynomite]

The brakes on the corvette failed today. I was coming to a stoplight, the car was slowing down when I pressed the brake pedal a little harder to come to a stop faster. At that time I heard a pop and the brake pedal went all the way to the floor. The car continued to roll forward and would not slow down.

When I lift my foot off the brake the pedal came back to the normal position. I was able to pump the brakes, but they had 0 resistance. The brakes are not effective. Also my BRAKE light is lit up in the gauge cluster all the time now. I haven't torn into the brakes yet, but Brake Fluid reserviors are both full, and I don't see any leaking fluid around the front brake calipers.

I don't really know what to start with if I should look at the pads, or something more serious. Any ideas?

Start with Brake Master Cylinder under hood drivers side fire wall. I expect your issue is NOT Brake Calipers or Brake Lines and obviously NOT Brake Pads. Suck the brake fluid out of the Master Cylinder Reservoirs with a Turkey Baster you can get at Target or WalMart before you disconnect the Brake Lines from the Master Cylinder.

If that happens again....grab the Emergency Brake left side of Drivers Seat and pull hard. Keep your thumb on the Emergency Brake Release Button so you can use the Emergency Brake as a Normal Brake.

[GOLDCYLON]

I think you lost the brake booster

[efnfast]

Keep in mind, when using the emergency brake, it only works the rear brakes. That means you've lost 50% of your braking, and the fronts do most of the work. Don't expect to just give it a light pull to stop the car. Probably something everyone should try in a safe place, like an empty parking lot. Just so you know what to expect when you need to do this.

Why not a thrown pad Cliff?

[Dynomite]

I think you lost the brake booster

I think you would still have some braking but a Hard to push Brake Pedal if it were the Brake Booster.


Why not a thrown pad Cliff?

Never heard of a thrown pad or for that matter some bolts or pins falling out of the Brake Calipers.
I guess anything is possible but then the caliper Plungers would extend and you would probably see a complete failure of the Plunger and brake fluid all over. In any event there would be all kinds of noise I would expect at the suspect Brake Caliper.

If the Brake Pads get sooooo thin as to end up with Pad Rivets on the Rotor.....there would be all kinds of noise at that wheel indicating the Brakes are going to hell in a hand basket ;)

I thought Jerry had Brake Master or Clutch Master Cylinders at one time and maybe Clutch Slave Cylinders on his web site??

[Billy Mild]

How will I know for sure that the master cylinder is bad? Anyway to test that? I don't have a jack anymore since my garage got broken into last week. I am going to try to get a jack this weekend and take a look. I will look at the pads first, then move on from there.

If the master cylinder was bad wouldn't the pedal stay on the floor?

If the brake booster went bad, the brakes would just require a lot of effort correct?

[ZZZZZR1]

Have you changed the brake fluid?

I agree with Cliff on the brake master...



:cheers:


David

[We Gone]

My guess I think you blew seals out in the master cylinder or a piston/ rod failure. If it was a line you would have fluid leaking out. A wheel cylinder the others would still work same with a pad failure. The light on the dash no pressure.

[mike100]

look in the footwell and see if the rear seal area where the brake pedal rod goes into the master cylinder is wet. Otherwise I'd think a rusty line blew out somewhere or one of the rubber lines gave up. you can always look at the ABS unit behind the drivers seat in the storage bin too.

[GOLDCYLON]

Mike lists the correct procedure to see if the area is wet below on the brake Master cylinder and the seals are compromised. I mentioned the booster as a POP was mentioned and both reservoirs were full. I have never heard a master cylinder pop but certainly fail with the pedal immediately hitting the floor. It's clearly either one or the other and I agree with Mike if the pedal arm etc is wet. I have seen two boosters fail in my life time and a loud POP was the first indication of trouble

[Billy Mild]

Have you changed the brake fluid?

I agree with Cliff on the brake master...



:cheers:


David

I have not changed the brake fluid. The only brake work I have done is replace the rear pads with some cheap Autozone pads to make it through the driving season. Over the winter I was going to swap to stainless steel lines, Hawk HPS pads, and some new rotors all the way around.

Mike lists the correct procedure to see if the area is wet below on the brake Master cylinder and the seals are compromised. I mentioned the booster as a POP was mentioned and both reservoirs were full. I have never heard a master cylinder pop but certainly fail with the pedal immediately hitting the floor. It's clearly either one or the other and I agree with Mike if the pedal arm etc is wet. I have seen two boosters fail in my life time and a loud POP was the first indication of trouble

I was thinking the same thing, but if the booster when out I would just have high pedal effort to stop.

[batchman]

Unless the brake pedal is unhooked you have definitely lost the master cylinder. Any other failure would still have some braking.

The good news is you are here talking about it.

The other good news is outside of bleeding it's a pretty easy job. Be sure to keep the brake fluid away from your paint.

All for now,
- Jeff

[Billy Mild]

Unless the brake pedal is unhooked you have definitely lost the master cylinder. Any other failure would still have some braking.

The good news is you are here talking about it.

The other good news is outside of bleeding it's a pretty easy job. Be sure to keep the brake fluid away from your paint.

All for now,
- Jeff

Don't new master cylinders need to be bench bled? I have a vacuum bleeder, but it sounds like I might be flushing the entire brake system.

I guess it will be a good time to do the lines, and paint the calipers?

[GOLDCYLON]

Don't new master cylinders need to be bench bled? I have a vacuum bleeder, but it sounds like I might be flushing the entire brake system.

I guess it will be a good time to do the lines, and paint the calipers?


Make a project out of it while you are there. I always bench bleed the master before install

[Billy Mild]

Has anyone bought a master cylinder lately? I'm looking at Advance Auto Parts and Rockauto. Advance auto has a ton listed on their site. They are all reman parts, but I don't know which one would be correct for my application.

[mike100]

I don't think the brake parts are ZR-1 specific outside of the J55 option. J55 ended up being standard on all 95 and 96's so all the parts except for the special Zr-1 brake booster should be obtainable from common sources.

[We Gone]

Last one I got was from NAPA casting had some minor differences but worked out great.

[Billy Mild]

There are a ton of Master Cylinders listed on Advance Auto Parts website. They all vary in price as well.

I noticed last night that the front reservoir for brake fluid was empty. I guess that confirms the bad MC?

[GOLDCYLON]

I noticed last night that the front reservoir for brake fluid was empty. I guess that confirms the bad MC?

Yes, since you already verfied no leaking at the calipers.

[We Gone]

There are a ton of Master Cylinders listed on Advance Auto Parts website. They all vary in price as well.

I noticed last night that the front reservoir for brake fluid was empty. I guess that confirms the bad MC?

That fluid went somewhere, If you can not find any leaks be sure to check the booster I have seen when the seals blow out it let the fluid drain into it. If not look to see if it ran down the front of the booster where the master cylinder bolts on.

[GOLDCYLON]

That fluid went somewhere, If you can not find any leaks be sure to check the booster I have seen when the seals blow out it let the fluid drain into it. If not look to see if it ran down the front of the booster where the master cylinder bolts on.

It's prob saturated into the carpet and pedal arm but who knows. Since the OP has not mentioned thats a good of guess as any. GC

[We Gone]

It's prob saturated into the carpet and pedal arm but who knows. Since the OP has not mentioned thats a good of guess as any. GC

Maybe but wouldn't it have to go thu the booster to get in the car??? I guess it could follow the plunger.

[Billy Mild]

I did some residue above the brake pedal inside the car last night.

Should I get a reman unit or a brand new one? Thoughts on either?

[GOLDCYLON]

I did some residue above the brake pedal inside the car last night.

Should I get a reman unit or a brand new one? Thoughts on either?

I think the Reman unit is ok for a brake master. In a remain alternator they only replace the parts that are bad. However, in the master cylinder they always replace the seals as nothing else really can go bad. Your mileage may vary

[phrogs]

The booster is just that a booster if it failed you still have hydraulic brakes just not light anymore you have to push on that pedal if if it stops its not the hydraulics.

But you need to dig in and see whats up

[Billy Mild]

I bought slotted and drilled Stop Tech rotors. I have Hawk Pads waiting to go in. Now the last decision is if I need to get some new brake calipers like Grand Sports. My only thing is you can't see them with my current wheels. I know sometime next year I will be getting A Molds. I also want some long tube headers and a chip. Decisions, decisions...

[Billy Mild]

Brake Fluid recommendation? Can I run DOT4 or must I run DOT3? Is ATE blue still the preferred fluid?

[mike100]

I run $6 quarts of parts store DOT3 myself. I can afford to bleed it yearly, but even so, DOT3 can absorb a lot more moisture than DOT4 so it is better suited to longer change intervals. DOT4 would be superior for track days I suppose, but would need to be flushed more often. The Ford Motorcraft brake fluid (the regular dot3) used to be rated at a very high boiling point for cheap fluid and was a favorite among road racers of street cars for a long time because they could afford to flush the fluid every weekend.

[batchman]

The Ford Motorcraft brake fluid (the regular dot3) used to be rated at a very high boiling point for cheap fluid and was a favorite among road racers of street cars for a long time because they could afford to flush the fluid every weekend.

+1 on the Motorcraft HD fluid. A higher than most wet boiling point, a lower than most cost, and readily available.

Happy bleeding,
- Jeff

[Billy Mild]

I have gotten the master cylinder replaced. I did a reverse bleeding process along with the traditional bench bleeding.

I have painted the calipers, and brackets along with putting new pads/rotors on the car. I assembled the front brakes today. Below are the results.

http://i856.photobucket.com/albums/ab123/billymild/zr1/IMG_20141205_162045_zpszavtbfr9.jpg

Cleaned up calipers after wirebrush
http://i856.photobucket.com/albums/ab123/billymild/zr1/IMG_20141117_184804_zpsqpryjbuh.jpg

During painting
http://i856.photobucket.com/albums/ab123/billymild/zr1/IMG_20141117_193652_zps8l3brdfa.jpg

http://i856.photobucket.com/albums/ab123/billymild/zr1/IMG_20141117_210027_zpsdytzh01w.jpg

Assembled:
http://i856.photobucket.com/albums/ab123/billymild/zr1/IMG_20141207_173800_zps0dbeghgs.jpg

I am running Stoptech Drilled and Slotted rotors up front and Hawk HPS+ pads. The rear I am running stock replacement discs and Hawk HPS+ pads.

I'm having an issue getting my rear brake hoses off. Does anyone have a recommendation on how to get them to break lose?

[Billy Mild]

I got all the Brake lines, pads, and rotors replaced. It ended up my Master Cylinder was not defective, it turns out the stainless braided brake lines from the master cylinder to the ABS pump failed. One of them busted. I went ahead and replaced the Master Cylinder since it was all apart. The lines I had custom made since they are NLA from GM. Thompkins Industrial made the lines and it was around $97 for both lines. Highly recommended. They did a great job.

I finally got around to bleeding the brakes today. I put in speed bleeders all the way around. These are a must have for any car. I am sold. I don't know why I waited so long to buy these. It took just under an hour to flush/bleed the entire brake system.

[Roadster]

looking good, you'll have to give us a review on your "new" braking system, they should stop on a "dime" for sure!!!

[Billy Mild]

Went for the first little test drive and the BRAKE light is still on. What causes this to come on? It has been on ever since my brake line burst.