Brake pedal goes to floor

[Amon]

Hi fellow Supra addicts

I've got a brake pedal that goes to the floor. I doubt it's air in the system because I spent quite some time and fluid on bleeding it. The pedal just progressively goes to the floor in a span of 3 seconds and brake force is very weak. My first guess is that it's the seals going bad in the brake master cylinder from age (24 years). I went to the dealership to ask for a rebuild kit and they said they only have a "special service package" that was about $170, which supposedly included plungers, springs, and seals.

Am I going in the right direction to get this kit from Toyota, or have I missed something? I have a donor car (1988) that suffered the same issue.

 

[gsxr141]

just take it to a regular garage. they will find the problem. that is if they are competent. are you sure there's no leaks? if no leaks, i'd say it's the master or booster.

 

[hvyman]

Sounds like a bad master to me. That is if you dont have any other leaks.

 

[mirage83]

Your system sounds like your MC is bad. I got a brand new OEM Aisin brake master cylinder last year from Champion for around $200, no core exchange or deposit. Of course I also replaced the brake lines and purged the system with fresh fluid.

 

[Amon]

I just took the car for a brief drive down the road and decided to give the brake pedal a a few pumps then quick hard stomp. I heard a popping sound and and then there was no brake force at all to stop

I drove home and looked underneath to find brake fluid leaking from a line right underneath the driver's seat. Seems like I burst a brake line underneath the car, which is odd because I didn't think the master had enough pressure for it. A quick look around reveals that all but one rear brake caliper is seized. So that poor brake performance was probably because just one caliper was working. It still doesn't explain why the pedal goes to the floor. There's no fluid in the vacuum line, so I know the engine isn't drinking DOT4 from a booster leak.

Anybody got a simple way of unseizing their calipers?

mirage83: what is this "Champion" you speak of?

 

[hvyman]

Champion toyota go on suprafroums.

The pedal would go to the floor with a leak or a bad master cylinder.

Sized piston or sized slide?

 

[D.J.T.]

I just took the car for a brief drive down the road and decided to give the brake pedal a a few pumps then quick hard stomp. I heard a popping sound and and then there was no brake force at all to stop

I drove home and looked underneath to find brake fluid leaking from a line right underneath the driver's seat. Seems like I burst a brake line underneath the car, which is odd because I didn't think the master had enough pressure for it. A quick look around reveals that all but one rear brake caliper is seized. So that poor brake performance was probably because just one caliper was working. It still doesn't explain why the pedal goes to the floor. There's no fluid in the vacuum line, so I know the engine isn't drinking DOT4 from a booster leak.

Anybody got a simple way of unseizing their calipers?

mirage83: what is this "Champion" you speak of?

Champion Toyota. A Vendor you can find on SF. Just post in there section a quote for the part/s you want & they'll give you a price & then make business with them