bleeding the brakes on my BN1

[bighealeysource]

Hey all,
A few weeks ago everyone was good enough to chime in on my
rear brakes rebuild, brake bleeding issues, etc. Well, I
have now bled my brakes so many times I feel like a vampire !
I've tried the new fancy tools and the old fashioned way
and still have a mushy pedal. I'm not getting any air in
the clear plastic bleed tubing and put everything back together and still mushy pedal. Used Norm Nock's Technical articles
and the service manual and still the above. When I am
driving and if I pump the brake pedal, it gets better but
still not like it was before yours truly replaced the rear
wheel cylinders. HELP - any suggestions on what to try
next ?
Thanks,
Mike

 

[BOBBYR]

Hi Mike,
Sounds like you've been having fun.Bleeding brakes can be pretty tricky.Please tell me the procedure you are using to bleed this system and I will try to help.You might want to PM me and it might be easier to explain.
Bobby R

 

[Dave Richards]

Lately, we've taken to pushing the fluid through from the master cylinder with a garden sprayer set up to be a pressure bleeder. On the last one, we had similar results to what you're describing and it turned out to be a bad master cylinder. It wasn't sending any fluid to the rear wheels.

 

[healeynut]

Hey all,
HELP - any suggestions on what to try
next ?

Mike -

I know this sounds like a retarded question but did you mechanically adjust the shoes both front and back?

Even if your system is bled, you will have a mushy pedal unless your shoes are adjusted properly... otherwise they just back too far off the drum then you get a mushy pedal when (typically) only three of the four brakes is making contact & you have to pump to get the fourth up to the drum. This will feel just the same as air in the system.

 

[bighealeysource]

Hey y'all,
Thanks for everyone getting back so quickly. I bled them starting with the
right rear and progressing as per the factory and Norm Nock's recommendations.
Attached a bleed tube to the bleed valve with the end in a container partially
full of fluid. Pumped the brake pedal - usually about 8+ times and kept it
down on the last stroke - until no air showed in the fluid. Made sure to keep the master cylinder full of fluid too. Tightened the
bleed screw back up and went on to the next wheel, etc. I did adjust the
brakes per Norman's tech article but as Alan said above, maybe I do not have
them adjusted properly. Particularly the front since you have to adjust both sides. I did adjust so the drum was just turning free of the brake shoes
and not binding but maybe I need to adjust a bit more. Suggestions as to
how much contact the shoes should be making when adjusting ? Also, I have
new brake linings coming from Austin Healey Spares ( thanks for the tip Alan)
so my current linings are pretty worn.
Thanks,
Mike