can any one explain this? urgent help!!!!

[marcello]

the other day i purchased all new brake components for my series 2a swb with 10 inch brakes.

upon bleeding the brakes i notice that the rear left wheel cylinder was leaking from under the dust seal on the forward facing of the two pistons.

off i go to return the part only to recieve another one with the same problem, same leak in the same spot???

has any one ever experienced this before?

i believe everything has been assembled correctly.

the only cause i can think of is that because the adjusters have been backed off completey, (the book says to do this when bleeding) the seals in the cylinder are being squashed out of shape by the pressure from the top spring that continues to pull this forward-most piston inwards towards the cylinder.

from what i can tell, the top spring is designed to attach between the little post on the back of the leading shoe and the post that is attached to the backing plate and its function is to keep the leading shoe on the adjuster. is this correct?

at first i thought prehaps with out the adjuster to stop complete piston contraction, this spring is pulling the piston past the inlet for the brake fluid but if this were the case i would expect more leaking than what i am experiencing?

sorry for the complicated messege, hope it all makes sense.

[JDNSW]

The wheel cylinder should not leak under any circumstances unless the piston is pushed so far in one direction that the seal moves beyond the bore of the cylinder. Assuming you have fitted a complete cylinder, not a kit, I think the most likely thing is you have a faulty cylinder. The fault will be either a nick or faulty moulding on the seal, or rust in the bore of the cylinder, which has damaged the seal or prevented it from sealing. I would contact your supplier about replacing it.

I have never encountered this problem when fitting cylinders, although I have encountered ones that did not last as long as I expected. Having a leak before you even get it together at least makes it clear the part is faulty.

John

[DEFENDERZOOK]

did you have the drum on when you were bleeding the brakes......?


if not.....you are simply popping the pistons out of the cylinder cos there is nothing to stop them.......

[richard4u2]

they didnt give you the same cylinder back to you ??
have a look in the cylinder and see if there is any rust spots