Leaking New Rear Wheel Cylinders

[varryparry]

I finally got all the new Master cylinder, front calipers and rear wheel cylinders installed. Also put new hoses on too. I started bleeding the brakes and both of the new rear cylinders were leaking quite a bit around the pistons. Was there something I missed on the install or would they be defective? ARGH!

Chris

[kwilford]

I moved this thread to the "Brakes" forum.

Hmm, were the rear cylinders brand new and already assembled? Or were they NOS (New Old Stock) from somewhere, or did you install repair kits? If they were NOS, perhaps they weren't stored correctly, and the rubber seals have perished.

Or, did you assemble the shoes and hardware incorrectly? Is it possible you missed something (like the little push rods that sit inside the cylinders and then push against the shoe), that has caused the cylinders to over-extend, allowing the seals to push past the end of the cylinder?

Or, are they leaking from where the brake line connects (a bad thread, or incorrect flares)?

Or, are they leaking around the bleed valve (loose valve, crossed thread, or...)

That's about all the ideas I have. HTH

[nobody]

Just a quick question, were the drums on? if not the pistons will be pushed out and it will leak. Sorry had to ask.

[BQS4]

There's also the possibility that the cylinders, if they are original, could be pitted and it wouldn't matter if you put in new seals, they'd leak anyway. Did you check them?

[varryparry]

They were new remanufactured cylinders. Were not leaking from the brake line or the bleeder valve. However, I did not have both drums on and now that I think about it, the 2nd side did not start leaking until after I took the drum off to see if it was leaking. I will try again with the drums on after I clean up all the brake fluid.

Grant, there's never a dumb question. Just another rookie mistake.

Thanks,

Chris

[varryparry]

Discovered the new cylinders were a different design than the old. I tried to use the old pushrods with the new cylinders. Found out that the new piston and pushrod are one piece instead of two like the old one. It caused the rubber seal to turn sideways. Put the new pistons back in and cut off the old pushrods so they were even with the end of the shoes and it works great. I discovered how well they worked when some old fart in a huge 4WD decided he needed to make a right turn from the left lane. He stopped when he heard the brakes squeal and horn honk but then still didn't see me and kept going around the corner. To keep him from hitting me I ended up driving around the corner to the frontage road half up on the median before he finally saw me. IDIOT!