I got A brand new AC Delco master cylinder for my '79 Catalina. I followed the directions as written on the page, only I used the brake pedal to do the bleed with the outlets plugged, I don't have a vise and figured that would be the next best thing. I double checked the bleed by running the motor and pushing on the pedal. This MC is bad as well, fluid seeps from the rear end and the pedal slowly sinks if you put decent foot pressure on. Am I doing something wrong, or is this bad luck?
There's no excuse for fluid seeping out the back, sounds like the master cylinder is defective. Is it "Hecho en China" (or Mexico)? Or, maybe it's been on the shelf for years and the seals have deteriorated due to age. (How much dust was on the box?)
All of these "OEM" parts I've put in the car have been Hencho en China. They're definitely not up to Dayton, Ohio OEM quality from the 1970s. The original MC and brake calipers/ cylinders were made in my hometown and lasted 42 years.
It's a real problem these days. In some cases you're better off with a quality rebuild of an original Made in USA item - but finding good rebuilds is another problem. What we need is a TARDIS to go back and buy high-quality real OEM parts! :silly:
too late the Daleks destroyed them all
How difficult is it to disassemble one of these? I ordered the OEM one on Amazon, so I could see the seals having been jostled loose from the box being mishandled. Is it worth trying, or would you just send it back?
I would just send it back. With China-made parts it would not surprise me if it had a porous casting or improperly machined bore.
I'll do that. I used the bad Advance remanufactured unit as credit toward one of their new ones. I only manually pressed the piston in about a half inch out of an abundance of caution. Some fluid appeared on the bottom of the cylinder, but the mount was dry inside, so that Isa little encouraging. I may not have the line snug. Can pushing the pedal all the way to the floor when bleeding brakes damage those seals? That's pretty much the only thing I can think of that I've done that could possibly have caused leakage.
Pushing the pedal to the floor shouldn't have damaged anything if it was made properly to begin with.
Get one from Autozone, O'Reilly's Rock Auto, etc., with a limited lifetime warranty.
