What happens when using the replacement rear wheel cylinders that are wrong? Is it an issue with them fitting to the backing plate or is it a problem with the function of them?
Thanks Don
Here are some pics.
Here are the new cylinder on the right, and an old lockheed cylinder on the left. Look pretty similar, but look at the angle the port is drilled at:
The old one has a drilling at approximately the 11 o'clock position.
The new one has it drilled a bit further round - somewhere between 10 and 11 o'clock.
What's the big deal?
Well, the deal is, the hole exits into the cylinder further up the bore. In my case with decent shoes and good drums, the piston was well back in the cylinder and the seal lip was back far enough so that the hole was open to the wrong side of the seal lip. The fluid just pissed out.
Here's the two holes on the good cylinder. They are roughly in the same area, the no mans land near the step in the bore.
In the quality product from China, the bleed hole is correct (hard to get that wrong) but because of the incorrect angle the feed hole is almost 10mm further up the bore.
With good or new drums and good linings on the shoe, even when adjusted up, the seal lip sits over the hole. The fluid just flowed out of the end of the cylinder.
How can people get something so simple so wrong?
Out of curiosity I checked the front cylinders and that look fine. The holes are aligned well at the same position in the bore.
I bought the cylinders from Macs, and have written to them about it. I am waiting for a reply.
I bought some more from a UK supplier, but they turned out to be the same. That's when I elected to rebuild the old ones.
Mart.
