Likely original wheel cylinders that I honed and rebuilt recently would not bleed, the two on the driver's side. The system was dry and the 2 replacement cylinders I used on the passenger side bled fine with a hand vacuum pump. But the 2 that I rebuilt just won't bleed even by pumping the pedal. There was fluid at the flare nut fittings and a trace at the bleeder screws but no stream you would expect. I replaced one of the rebuilt units with a new one today, and it bleeds fine. I'm waiting the last one one to be delivered and I'll replace the last of the rebuilt originals. After honing the bore appeared smooth. The piston seals went in with no issue. The bleed and supply line holes were open and clear. Anyone ever had a similar issue? It's a 67 R/T with power drums all around.
Can't bleed rebuilt wheel cylinder
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Yes, fluid comes out of the lines. I figured if the piston seal to cylinder bore interface was not ideal it could suck air when pulling vacuum. But that doesn't explain no fluid when pumping the pedal. As I said in the main post, after replacing the unit it bled fine. When I get a chance I'll pull one of the rebuilt units apart and try to find out what the problem was. Thanks!
Take the bleeder out, if no fluid comes out have someone push brake pedal gently. Don't let it piss on you. If none come out poke a small wire in hole. Clean bleeder make sure it's clean. Any possibility you assembled wheel cylinder to cover bleeder hole?
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Good points. Thanks. I'll need to double check the bleeder screws. Likely being the originals, the wrench size is 1/4 inch and is much smaller than the screws on the new units and could be obstructed. I don't think the seals covered the bleeder hole because the driver's side front cylinder worked when I pumped the pedal (I had a "helper" video it) to "push" the shoes against the return springs so I know the pistons were pretty far out.
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Have you adjusted the shoes up fairly close ?
If not, all your foot travel is being swallowed up by the shoe movement. Then no pressure will build up in the fluid lines.
Shoes are good. Adjusted for just slight drag... I'm leaning towards blocked passage in bleeder screws. They're pretty old at this point and the car had no brakes for at least 20 years so there could be crud in the middle somewhere. Can't really see thru it since it's not a straight hole. Hopefully I'll solve the puzzle this weekend. But by then I'll have the last new wheel cylinder installed. Thanks!
Cleaning the crud out of bleeders is standard operating procedure.
Unless they're brand new.
Unless they're brand new.
It stopped good in '97... I had soaked the screws in PB Blaster for a few days then blew "through" them with brake cleaner (I don't have ready access to compressed air).The teeny tiny holes are not straight thru so it's hard to really tell if they're free to flow, which they were obviously not. The new cylinders all bleed properly now. Even tho I hate to use Chinese parts and prefer to rebuild the old US made parts, I need to get the car mobile again. I can always get back to the originals at some later time I suppose, including the original master. Thanks.
flyingfeathers
Well-Known Member
Yes I had the same problem with the bleeder screws use a regular paper clip perfect and also clean the valve were all the brake lines connect to it took me almost an hour to finally flow good luck. 
Did that, used fishing line to snake through them blew cleaner thru it but it wasn't the problem. I figure the chineseum rebuild kit's rubber piston seals are slightly longer than what's required for the original wheel cylinders and the rubber blocked the bleed orifice.
The solution? I just replaced the wheel cylinders with chineseum cylinder assemblies. I really didn't want to do it, but now the new cylinders bleed fine. The chineseum bleeder screws are also much more substantial than the tiny originals. I used a vacuum bleeder and had no issues. Thanks.
The solution? I just replaced the wheel cylinders with chineseum cylinder assemblies. I really didn't want to do it, but now the new cylinders bleed fine. The chineseum bleeder screws are also much more substantial than the tiny originals. I used a vacuum bleeder and had no issues. Thanks.
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