Fun with wheel cylinders


Active Member
Feb 24, 2021
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Good Day All
While the party barge ('65 Newport) is in dry dock, I thought that this would be an opportune time to finish replacing the wheel cylinders.
The project was to refurbish the brake system with new lines (flex and hard-not stainless), and new cylinders to include the master. The front cylinders and lines were no problem. The rear however, took a couple of days. The rear hard lines were close but a little to long on the drivers side. Not a problem as I have a double flare tool. With the lines installed the nut would bottom out against the cylinder before the flare would seat. Removed the line again, replaced the 'short' nut with a 'long' nut and try again. Once reinstalled the nut would tighten but the fitting would leak between the nut and the tube, When I install hard lines I use a dab of Loctite 567(?) on the tube. Slide the nut up and turn it to distribute it around the tube. I also use a dab on the threads.
One again the line comes off. I clean everything examine the double flare (no issues noted) and reinstall. Same result; leakage between the nut and tube. One more time the line comes off. I now remove the drum and disassemble the brake hardware,and remove the cylinder. I measure the depth of the seat and it is 3/32 deeper that the original. I also notice that the seat in the cylinder has what appear to be serrations on the face of the seat.
I return the offending cylinder back to the parts store and pick up another one (along with some more brake fluid). The seat depth is still 3/32 deeper but the face of the seat appears to be smooth.
Once home I reinstall everything and bleed the brakes. I block the brake pedal with some wood to keep pressure on it and leave it for 6 hours. (The battery is out of the vehicle). After 6 hours all is well.
The take-away is that you need to inspect EVERYTHING when dealing with Chineesium parts.
Merry Christmas to All
Not a shocking story with lots of parts store brake parts these days unfortunately.
I once got a cylinder from o'reilly with a bleed screw in it that didn't have a bleed hole drilled in it... so basically a plug nut. I'm like wtf.
Glad it worked out for you!
It doesn't take much of a defect on the seat to cause problems.

Glad that you got it sorted out.

Unless the bores on your original cylinders are badly pitted I recommend rebuilding them. The chinese castings are not up to the original standards. Seal kits are easy to find.