Brakes won't bleed

[ichthos]

Hello,
I am trying to get a 69 TR6 roadworthy that has been in storage for many years. I am currently working on the brakes. I had the brake master cylinder resleeved by Apple Hydraulics. I also rebuilt the rear brakes, including putting in new hoses. I am unable to bleed the rear brakes and I am not sure why. When I depress the brake pedal, all I get is a lot of air and a little dribble of hydraulic fluid. Any suggestions?
Thanks, Kevin

 

[Trevor Triumph]

It seems it takes some pedal pushing to get the fluid to the rear cylinders. I've had some success with a vacuum bleeder and years ago I used pressure (about five pounds)from an air compressor. Make sure all the fittings are tight. Is it possible the washers were installed backward? Then there's my great installation when I confused the new and old washeres and reinstalled the old pieces on the master cylinder and wondered why I had no brakes! T.T.

 

[DougF]

Make certain that you don't have leaks at any of your connections. Are you having to add fluid to the reservoir after pumping ? What condition are the lines in? Do you get the same results from both sides? Did you make sure there were no obstructions in the lines? What condition are the wheel cylinders in?

 

[ichthos]

There are no leaks that I can find. I am not adding fluid to the reservoir. I am puzzled by the fact that plenty of air comes through but very little fluid (which is not clear) comes through. I thought that perhaps the lines might be blocked but they bleed about the same on both sides. I put new parts in the wheel cylinders. When they resleaved the brake master cylinder, they also put the piston back in with new parts. I may take it back apart to make sure all pieces were put back in correctly. Any other suggestions?

 

[Bugeye58]

Try cracking the line to the rear brakes at the master cylinder, and see if you get fluid flow there. That will help isolate the problem. If you get good flow at the cylinder, you can progress downstream and see where the problem lies. My next guess would be the flexible hose from the hard line at the rear.
Jeff

 

[mgbmedic]

As you pump the pedal, does the pedal come up off the floor at all or does it stay to the floor? If the pedal doesn't rise after pumping several times and, as you hold the pedal to the floor, you hear air when the bleeder is opened, it sounds as if your making headway, although slow, but it takes alot of patience. It can take alot of repetitions to get that much air out. If your getting a release of air under pressure, then it's working.

 

[ALLAN]

(Gravity Bleed)--In stuborn cases something that has worked for me before including my tr6 is this, open the rear bleeder valves, loosen the master cylinder cap, the brake fluid will very slowly drip out,(and I mean real slowly) it may take one to three days to expel the air. Then you do the same for the front. To avoid a mess attach a rubber hose to the bleeders and run into container. After this has been done you will have some pedal and then the car can be bled normally. At first you wont see any fluid drip out but the next day you will see a small amount of fluid in the container. It is a slow process but it beats the frustration of pumping the pedal and nothing happening. I dont guarantee this but it worked for me on three cars. dont forget to keep topping off the fluid.

 

[Bugeye58]

Kevin, did you bleed the M/C before you installed it?
Jeff

 

[ichthos]

I did not bleed the master cylinder before I installed it. I have not done this on older american cars I have owned and they have still bled fine. This is the first British car I have owned. Is this something normally done to a TR6? How do I do I bleed it before putting it in?

 

[LastDeadLast]

ichthos,

I tried for days to get a new a brake system bleed without bench bleeding the master cylinder. I finally took it off and bench bled the thing and finally got it working.

 

[piman]

Hello all,

before I had a pressure bleeder, I used to find the quickest way to get fluid through after a complete rebuild was to go to the furthest wheel, slacken the beed nipple and have an assistant push the pedal to the floor, then I just put my finger over the beed nipple. The assistant then lifted the pedal, I lift my finger and one push\hold, finger on etc. I found that this worked well. I have never bench bled a master cylinder and can't see what use it is?

Alec

 

[TR4nut]

Same experience here. Start with farthest cylinder, and have an asistant work the peddle. Unless you have good equipment which I don't its a 2 man operation.

I think it helps to open and close the bleed nipple during the cycle, either with wrench or with your finger. My TR4 has a single system brake m/c so it is a bit easier I think, but getting the last bit of air out of the m/c was difficult. Best way we worked out was have the assistant push rapidly on the brake pedal and eventually the air worked itself out.

On a 6 with a dual system you can easily have the problem of the PDWA switch getting moved to where the brake light stays on. If it does, once you get the air out all you need to do is bleed one side, then the other if necessary until the shuttle resets itself. Helps if you know which way the shuttle went.

Randy

 

[martx-5]

I have always found that it definitely helps to "bench" bleed the master. I ususally do it on the car however. Just make sure you have enough rags underneath to catch the fluid, has it's a great paint remover. Have someone work the pedal while you loosen and tighter the two lines going into the master. Push down on the pedal, loosen the lines, and pause a few seconds. Tighten the lines. Release the pedal, and again pause a few seconds. The pausing allows the air in the fluid to rise so it is more easily expelled when the lines are open. Once the fluid starts running clear, you can then easily bleed at the wheels. /ubbthreads/images/graemlins/driving.gif

 

[mrv8q]

I'm going to agree w/ Bugeye here. Faced w/ the same situation on my TR3, I got scared when got nothing from repeated brake pumps. Cracking that line really helped! Good Luck!
Best,
Kevin Browne
'59TR3A #58370

 

[ALLAN]

I know my gravity bleed that I mention above sounds a little stupid and I thought it was a stupid idea untill I tried it, and it worked. That was after bench bleeding the master and using a vacume pump to bleed and alot of pedal pumping. it takes more time but it beats the frustration and work of all the other techniques.