[nc55]

OK guys, help me out. I put new front disk brakes on my 55 about a year ago,and have had no problem untill recently. when i first put on my brakes the pedal is normal, but then the next time i have less of a pedal untill the pedal is to the top and the brakes start locking up. something is not releasing. could it be my master cylinder? something is stopping the piston in the calibers from releasing. any advise?

 

[[email protected]]

Hi,First find out which wheel is locking up.It could be a bad brake line[Collapse] If they are rubber!!!.It also could be the proportioning value going bad. Any Leaks??? Good luck Billydee Rusty56

 

[nc55]

thanks Billy, both wheels are locking up. this is why i thought the pistons weren't releasing. no brake fluid loss.

 

[nc55]

this only happens when the car is running, sitting in the garage, cold i can pump the brake pedal as many times as i want and no change. also,i don't have a power booster. any ideas?

 

[Todd_J]

I just installed disc brakes as well and have the same problem after running a few miles. I have a booster so I put washers between my booster and master cylinder as a troubleshooting technique to see if I had some preload. It did which tells me as my brakes heat up I am getting some preload on the master cylinder. I called CPP and they said I had air in the system and needed to bench bleed my master cylinder again. I have not done this yet so I don't know if it will work or not but worth a try. I did bench bleed the master cylinder when installed. I am hoping that loosening the lines that go into the master cylinder from my proportioning valve one at a time to bleed the air out would work.

What do others think? Can air in the master cylinder (or brake lines) heating up cause this preload condition?

Thanks
Todd

 

[nc55]

hoping someone can suggest an idea to fix our problem

 

[acardon]

The link from the pedal to the booster or M/C is too long. Shorten the link and the problem will go away. The fluid is not returning back to the M/C after you apply the brakes. The fluid heats up and expands after you drive, which causes the brakes to lock up. That's the reason it doesn't do it in the garage.

 

[nc55]

but i have drove this car over a year with no problem, does the link from the pedal to the M/C grow?

 

[acardon]

It could be the hole at the bottom of the M/C reservoir is stopped up.

 

[nc55]

thanks acardon, your advice was right on the money. took all of 5 min to fix. backed off rod a few turns and problem solved. thanks again