No Brakes!!!!!!

[Alfonso Gomez]

Currently, I'm not using my '87 Coupe very much because of the price of gas in Puerto Rico (on average, 72 cents a liter for regular unleaded and close to 80 cents for premium. So, I put $20 worth of regular and drove around doing some errands.
While driving back home, I noticed the brake pedal was a bit higher than usual but paid no attention to it. After taking off from a traffic light, I got real close to the car in front and started braking when the pedal went to the floorboards. NO BRAKES!!!!!!
I immediately swerved to my right and frantically pumped the brakes but to no avail. Since I was doing about 30 MPH, I shifted from Drive to first gear to slow the car down before the next traffic light.
I was about a mile from my house so I crawled VERY SLOWLY home.
As soon as I parked the car I opened the hood and found that the brake fluid reservoir was full. But it was very hot. Also the front brake hoses were very hot. I could not find a leak in the front hoses or fluid leaking from the front calipers or the rear ones. So I must conclude that the master cylinder is shot.
This item was replaced about 3 years ago with an EOM unit which I purchased from a GM parts dealer.
Maybe the heat damaged the rubber parts inside but I have to wait until I disassemble it to be sure. If I find the rubber parts damaged I will replace the whole unit but I have to do something about the heat.
My questions are: Is it normal for the master cylinder to get very hot? What can I do to reduce the heat in this item? Will a home made heat shield work? Has anyone experienced this situation? The coolant temp reading was about 190 degrees at the time but I understand this is normal for these engines. Also, I do not have headers in my car and the factory heat shields are installed.
Any help will be appreciated.

P.S. Before submitting this thread, I went to my car and tested the brakes and they were OK. The incident was two days ago, so now the car was cold.
What is the matter?????????

 

[Rabbit]

This is a pretty good trouble shooting guide..http://www.classicperform.com/TechBook/BrakeTroubleshoot.htm

 

[6speeder]

"... the brake hoses were very hot".....

It is possible that the parking brake is "dragging" causing the brake fluid to boil. Boiling brake fluid will cause bubbles in the system, preventing compression of the fluid during braking. Check your parking brake.....

 

[Alfonso Gomez]

"... the brake hoses were very hot".....

It is possible that the parking brake is "dragging" causing the brake fluid to boil. Boiling brake fluid will cause bubbles in the system, preventing compression of the fluid during braking. Check your parking brake.....

It is not dragging, the shoes of the parking brake are very worn out.

 

[Tuna]

I'm leaning toward boiled fluid also.
Maybe one of the front calipers is sticking, making the pads rub the rotors too hard all the time, thus boiling the fluid in the front.
Maybe master cylinder was sticking and not allowing the pads to fully return thus heating the pad/rotors and boiling the fluid.
Maybe the brake pedal is sticking on something and not allowing it to return to the top, ------

Just my thoughts.

For sure, it's time to bleed the brakes and put in fresh fluid.

 

[6speeder]

It is not dragging, the shoes of the parking brake are very worn out.

The heat in your lines is caused by friction somewhere. Jack each wheel and spin it to determine any excessive pad contact.

 

[jmccloud]

Hot, dragging brakes

I've had 3 cars with dragging brake pads due to failed brake HOSES.
The failed hose allows pressure to the slave cylinder and pads but doesn't release the pressure when the pedal pressure is removed. Brakes overheat and the brake fluid boils.
When I first heard of this I couldn't believe it and replaced pads and calipers. Two sets of pads later, I replaced the hose (at the caliper) and no more problems. This was so difficult to believe, it took two more times with two other cars (all GM) for it to finally sink in.
The diagnosis is to jack up a wheel, press hard on the brake (engine on for power brakes), release the brake and try to spin the wheel. It shouldn't drag. If it does, loosen the brake bleeding valve. Spin the wheel again. If it's free, the hose is bad. If that wheel is OK, go to the next wheel.
Hope this helps.

 

[G Winter]

Huummm

I think I may have this issue on an 89 Riv. Thank You.

Glenn

 

[Ghost~3~]

I've had 3 cars with dragging brake pads due to failed brake HOSES.
The failed hose allows pressure to the slave cylinder and pads but doesn't release the pressure when the pedal pressure is removed. Brakes overheat and the brake fluid boils.
When I first heard of this I couldn't believe it and replaced pads and calipers. Two sets of pads later, I replaced the hose (at the caliper) and no more problems. This was so difficult to believe, it took two more times with two other cars (all GM) for it to finally sink in.
The diagnosis is to jack up a wheel, press hard on the brake (engine on for power brakes), release the brake and try to spin the wheel. It shouldn't drag. If it does, loosen the brake bleeding valve. Spin the wheel again. If it's free, the hose is bad. If that wheel is OK, go to the next wheel.
Hope this helps.

I've "SEEN" that EXACT problem occur a NUMBER of time's on the Police Car's I work on everyday for Oakland Ca PD, Those car's and the brakes are subject to EXTREME Abuse on a daily basis, and it does sound like that
may be the problem in this case..."Bad Brake Hoses".

Best to pull all the wheel's check for "Blued/OverHeated" Disc Rotor's,
Disc Rotor's that may either "STICK" TIGHT in one spot, or be very HARD to
rotate at all. Check for ODD wear on ANY Disc Pad, they should wear evenly
if all is well. Check for a Caliper that is "STUCK" on it's slide's, and doesn't move reasonably "Free", will most LIKELY have ODDLY worn Pad's.

Any Brake hose's that are "SWELLED/CRACKED" in any way should be replaced!!

Rotor's that appear "Blue" or have discolored "Spot's" on the brake surface
area should be replaced!! If NOT... Are the Rotor's still within spec's to
allow machining a new surface??

When inspecting the caliper's look at the "Dust Boot's" around the caliper
piston's, are THEY Cracked/Torn??? allowing road dirt into the pistons.
Same for the Caliper Slide Boot's. Any of that indicate's caliper replacement
or Rebuild.

For SURE check All the Wheel bearing's, BAD Bearing's can cause a rotor
caliper assembly to NOT Rotate "True" and cause BAD Brake wear.

One way or another it sound's like a Good Brake job is in order when there is a TOTAL loss of brake pedal and in that case...

Just for "Piece of Mind"....I'd replace the Master Cylinder, and CERTAINLY
completely flush the system of "OLD" Dirty Brake fluid, No Matter what!!

Hope this is of some Help???

 

[Hot Rod Roy]

When you replaced the master cylinder, did you check to be sure the pushrod that is between the booster and the master cylinder was adjusted correctly? If this pushrod is too long, the brakes will drag and overheat, making the whole brake system get hot. It's easy to check that the pushrod is the right length. Remove the master cylinder caps, and with the engine OFF, depress the brake pedal (not too fast) and you should see a small spirt of fluid from the ports on the bottom of the reservoir. (If you depress the brake pedal too fast the fluid may squirt out the top of the reservoir.) If the pushrod is too long, there will not be a spirt of fluid.

To fix this, remove the master cylinder from the booster (no need to remove the brake lines from the master). Gently pull out on the pushrod in the booster, hold the shaft with pliers, and turn the tip of the pushrod CW to shorten it.

If the pushrod is too short, you will have a spirt, but the brake pedal will be lower than it should be at the bottom of the pedal stroke. You should see the spirt just as soon as you move the brake pedal a little bit.

S.T.W.