I replaced the innards of my brake master cylender on my original 2 reservoir 1972 40. I have bled and re-bled the brakes (4 times) and see no air yet very consistently cant get good braking after the first push of the pedal. But the quick second is solid and feels great. If the pedal is at the top for just a moment, the engagement is then the same, 2 pushes needed. The brakes were adjusted well before I took off the master. In that first push, there is no wondering one direction and with the minimal engagement i do get. What could the issue be? The only thing I ever find in my research is air as the culprit, but it is so consistent that I feel like it could be something with the rebuild kit. Could this be possible? Any ideas would be appriciated.
Brake issues after master cylender rebuild
- Thread starter Tigger72
- Start date
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Set your shoes all the way out to locking the drums. Then bleed the system. At least 2 refills of the master to do the passenger rear, then one for driver's rear. Next passenger front 1 refill, then drivers front again one refill. Now back the shoes off the drums like 4 clicks.
I have used a one man brake bleeder for years, but all the new cylinder suck air at the nipple due to poor threading they do these days. 2 people works much better. Got some sort of vibrator to set on the master cylinder for a few hours to help shake any bubbles up to the top.
I have used a one man brake bleeder for years, but all the new cylinder suck air at the nipple due to poor threading they do these days. 2 people works much better. Got some sort of vibrator to set on the master cylinder for a few hours to help shake any bubbles up to the top.
If the pedal still feels springy after a couple of quick pumps, then it's air somewhere.
If its hard then you need to adjust the brakes some more.
If its hard then you need to adjust the brakes some more.
- Thread starter
- #6
Thank you! I did pick up a cheap vacuum bleeder and saw exactly what you said... almost useless. My brain is having a tough time wrapping around the tighting of the brakes componant, though I have read that. Not at all disagreeing, just wondering, how would the moving of the pads out help if they were in good adjustment before the air was introduced. Wouldn't that move less fluid to move air out in the bleed process?
I ended up using Aviation Permatex on the bleed nipple threads so they quit sucking air. When the shoes are out, stepping on the pedal a few times will center them better than having them move out to the drums.
Bench bleeding the master is different than bleeding the lines and slaves. It should really be called firewall bleeding, that's where I do it. I got two short lengths of brake line off the shelf at my FLAPS, bent them so they would reach from the master outlets back into the reservoirs. Fill the reservoirs and pump the pedal a lot. Pump until you get no bubbles, attach the brake lines and bleed the rest of the system
