Brake pedal went to floor

[Tigerdadgc]

Last week my left rear caliper froze up while I was at the Nascar race in Richmond, and the pad wore down to the rivits which in turn tore up my rotor. I think my caliper froze up when my girlfriend jammed on the brakes at an exit ramp. I tried every thing to turn the piston in on the caliper with no luck so I removed and replaced the rotor, caliper and pads on the left rear. I turned the ignition on and got zero flow to the caliper. I then started the motor and the bleed appeared to be normal. I have been driving the car all week with no problems, pedal felt great. Today I rolled up to a stop sign and the pedal went all the way to the floor. The brake fluid is full and I have no leaks anywhere. Does anyone have any idea whats happened. Do I need to bleed all the brakes? I need some help!!!!!!

Mike

 

[Roady94]

- If you truly bled the brakes completely, and if you really had no braking problems after a week of driving, and there is truly no leaking anywhere, and the reservoir is full, then the problem can only be at the master cylinder. Fluid by-passing the seals as you push the plunger (likely) or pedal disconnect from the master cylinder (unlikely). That's my take anyway.

- Jay

 

[1993MTXSHO]

3 things

1) did you replace the rear brake lines, those sometimes prevent flow to the rear caliper, most of the time flow back when the caliper has to release and in turn making you think the caliper is frozen.

2) did you bleed them in the proper order

3) you're master cylinder is bad, (this is you're problem now, but I just threw the other 2 out there for future reference)

EDIT: ahh you beat me!!!

 

['94SHO]

What is the fluid level? If you are missing fluid, I would say a rusted line (rear?)
If not,first bleed the brakes in the proper order.(longest distance to shortest).
Then bleed the master cylinder, first rear, then front. Check for swollen hoses. Is your fluid clean or black? Black fluid indicates deteriorating rubber hoses. this may lead to improper brake operation. Is there any sign of leakage?

 

[Tigerdadgc]

Update

I removed the left rear brake line today and tried to blow on the brake hose and very little air passed through. It seemed blocked. I am going to bleed in the AM, we'll see!
Mike

 

['94SHO]

AS your rubber lines age, they swell, and expand.(and deteriorate)this can cause them to either
become spongy, or, the can cause brake "drag".. Neither is good. Also, the debris can cause ABS malfunctions.

 

[Devin]

During my rebuild I had my front brake lines open for a few years. When I reassembled anything it took forever to bleed the brakes. After about 5 tries over a few months the brakes are just as bad as ever. The car will slow down incrementally when the pedal is touching the carpet. After reading this thread I decided to have a shop look at it. I'll give a report with their findings.

I'll add in my situation I drove about 12 miles and eventually I heard and felt a grinding through the brake pedal when stopping.

 

[Tigerdadgc]

Brakes fixed

I removed and replaced the left rear brake line, bled the brakes and the brakes are working great. I guess I can assume that the left rear caliper being without good flow caused it to lock up. Anyway its fixed! Here is another side bar fix. When I pulled the caliper off the antiskid sensor was loaded with metal shavings. Could this have any effect on why my cruise control quit working, because it works now! Awesome! Any feedback would be appreciated. Once again this site saved me some big bucks. Thanks to all for the input!

Mike:woohoo:

 

[Roady94]

- Glad to hear your brakes are working again. I'm at a loss to explain how your "fix" solved your problem. Since you were driving for a week with good pedal and good braking response, and then experieinced pedal-to-the-floor without any fluid leakage, I can't see how replacing a brake line would fix the problem.

You said you finally got a proper bleed after the caliper replacement, and I trust that you verified proper caliper operation at that time, so I'm excluding a caliper piston hung in the open position and then freeing itself a week later as a source of the problem. Seems you would be aware of an inoperable rear caliper anyway and not declare "no problem" with braking performance.

If the problem was the flexible brake hose you replaced, it would seem that the inner lining failed and allowed the outer case to balloon. I have seen a flexible line ballon to the point that a "good" pedal can suddenly stoke to the floor, but always (three instances) the line is leaking at the fittings or elsewhere. You state with certainty that there was no fluid leakage.

I'm not questioning you mechanical skills or the fact that you have a solution. Just curious as to what you attribute the problem. Seems I need to learn something new here.

- Jay

 

['94SHO]

Don't forget to grease your slider pins, and check them for proper operation.
After my recent brake job, found out one slider on BOTH fronts were frozen...
This was after a short drive, with smoke coming from the front.. So, basically,
if you ever have more wear on one pad, the sliders are probably not sliding..
F.Y.I.

 

[Tigerdadgc]

So far so good

Roady94,

I appreciate your feedback, I double checked for leaks and could not find one. When I pulled off my right rear tire the brake pads were like new. All I know Is I could not rotate the piston with the bleeder screw loose. I blew through the left rear brake like and got way too much resistance, I was crunched for time and did not think to blow through the new brake line to compare. The hosed looked ok which surprised me. All I know is it bled just like the other 3 brakes this time after changing the hose. It still is a mystery to me about what happened in the first place. Metal to metal grinding out of no where. Brakes are still working great so I'll keep my fingers crossed.

Mike

 

[Roady94]

- Well, at least I'm not the only one confused. I'm hoping the good news lasts too. Thanks for the reply.

- Jay