PDA

View Full Version : TR6 Brake problem



ceedub
11-22-2014, 04:22 PM
We are having an issue with our new brake system. We have excessive brake pedal travel with little rear braking. The front brakes seem to be working OK. We have noticed that when the pedal is depressed the the level of the fluid in the front chamber of the master cylinder rises with each depression of the pedal. We have rebuilt the brake master cylinder so assume that is OK. We have bled the system multiple times. Any thoughts what the problem might be?

trrdster2000
11-22-2014, 05:19 PM
ceedub, adjust the rears until they are locked, then see what you have. That gives a start on what it isn't. The master repair can sometimes go wrong, have you been doing this before???

Wayne

ceedub
11-22-2014, 06:18 PM
Hi Wayne,
We did lock up the rears with no luck. We are thinking that the MC may have been bored out and thus the new secondary piston seal is not working as it should. Instead of fluid being pushed out to the back it is being pushed back into the front of the MC. We have not done a MC repair before but were pretty careful how the seals were installed.

trrdster2000
11-22-2014, 07:21 PM
Ceedub, You do have a M/C problem. The seal at the rear is the one that holds fluid in the rear brake chamber. If you did hone it out too far it will by pass the cup and go into the front chamber. Sorry to say you will need another one to repair or get a new one.

Wayne

Zip960
12-02-2014, 03:42 AM
At this point....I would carefully disassemble the M/C and inspect it. Condition/orientation of seals, metal burrs, FOD. Maybe a seal disintegrated/tore.

ceedub
12-04-2014, 06:22 PM
We did not hone the MC but upon taking it apart and more careful inspection we could see that the deepest part of the bore was a little chewed up as if someone had tried to hone it and was not too successful. So, I bit the bullet and bought a new MC so when I get a little time I will replace it and bleed the system yet again, hoping that we will have some braking. Sure glad I used dot 5 or there would not be much left of my engine compartment paint.

trrdster2000
12-04-2014, 06:36 PM
ceedub, Dot 5 can start World War lll here, but I agree with you. I did the master on the '37 MG in the '80's and it sat until 2012, I did pump it once in a great while. We gave it a couple of pumps when we moved and it blew the rear flex hose. Good stuff.

Wayne