Leaky Master Cylinder ???

live4theking

Old Man with a Hat
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Guys I would like your opinion. I'm putting my Dewey booster on. When I looked at the back of the master there was some yucky moisture. Not a lot, in fact I cleaned it out with one q tip.

Do you think that indicates a learning master cylinder?

See attached pictures. The one of the master cylinder is after cleaning.

Or is it just moisture causing rust?
20200622_200335.jpg
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If you have any doubts about it leaking, replace it. Not worth risking a fresh booster to find out.

Dave
 
I think rebuild kits are still readily available and very cheap, consisting of pistons, seals, check valves, and a spring or two. Factor in the small cost of a brake cylinder hone (at any auto store) and you can have that master cylinder rebuilt in 45 minutes. I think this is a much better choice than buying a "rebuilt" unit that's mostly a paint job.
 
John. If you wind up going re-man. If it waz done by Cordone WALK AWAY FAST. They used to sell crap when they were domiciled in New Jersey. They moved their entire operation to Mexico 'bout 8-10 yearz ago because of the Cheap Labor soooo? Personally, I'd try to find a new one, try ROCK AUTO. You'll find Cordone there too but now you've been warned 'bout that outfit. I had ah kid in a cycle shop one time ask me how much should I pay for a helmet. I waz just in there buying some Klotz for my 2 cycle Dirt Bikez so I answered him with a simple question: HOW MUCH IZ YOUR HEAD WORTH? I feel the same way about Brakez, Jer
 
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John. If you wind up going re-man. If it waz done by Cordone WALK AWAY FAST. They used to sell crap when they were domiciled in New Jersey. They moved their entire operation to Mexico 'bout 8-10 yearz ago because of the Cheap Labor soooo? Personally, I'd wait for the new one from Napa. I had ah kid in a cycle shop one time ask me how much should I pay for a helmet. I waz just in there buying some Klotz for my 2 cycle Dirt Bikez. I answered him with a simple question: HOW MUCH IZ YOUR HEAD WORTH? I feel the same way about Brakez, Jer
You can preach that all day long. I've got a new one coming from a local parts house that I deal with routinely. The only thing more important that going is stopping I've been known to say. I don't buy cheap helmets either. They normally run $300 or more. Unless I can find last years model being clearance. I've been looking lately and the best price I can find for what I like is about $330 then they go up to about $500.
 
Jer,
It will be the whole crew this year. You meet Olivia and Aaron the oldest two. The last two years Nathanael was along too. This year my wife, Michele, and our youngest Cordelia will be there too. Cordelia is a thief - she steals hearts at the drop of a hat.

Here's my next helmet.
https://motorgearstore.com/us/nolan-n100-5-special-n-com-011.html
 
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I got the new master today. I remember someone saying about check valves in the ports where the lines hook up, but I cannot remember for what setup. Old and new look identical - are they correct.
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I got the new master today. I remember someone saying about check valves in the ports where the lines hook up, but I cannot remember for what setup. Old and new look identical - are they correct. View attachment 384186 View attachment 384187
Those are both offshore replicas of the original 4 wheel drum MC. They should have a residual pressure valve beneath each of the brass fittings although you can't see without removing them. Cross your fingers and say a prayer that it works as designed. Hopefully you're luckier than I have been.
 
Those are both offshore replicas of the original 4 wheel drum MC. They should have a residual pressure valve beneath each of the brass fittings although you can't see without removing them. Cross your fingers and say a prayer that it works as designed. Hopefully you're luckier than I have been.
What were the issues you experienced?

I bench blessed the master last night and did a quick test drive, but I didn't like the way it felt. The pedal didn't return when I left off and actually held.

We bleed the brakes, but it was late when we finished. I'll do another test drive tonight.
 
What were the issues you experienced?

I bench blessed the master last night and did a quick test drive, but I didn't like the way it felt. The pedal didn't return when I left off and actually held.

We bleed the brakes, but it was late when we finished. I'll do another test drive tonight.
I've had 4 MC failures over the past 20 years or so on different cars. All were new, at least one was the more expensive NAPA. 3 of them leaked like yours & 2 failed outright in traffic (they did pump up enough to get me home). I now rebuild all my own MC's and have had zero problems since. It takes some care & knowledge to do properly but not difficult; there are a number of good outfits that will do it for you if you like.

Queries to local mechanics indicate that MC's & many other overseas parts (even OEM such as AC/Delco) are substandard and require warranty replacement. Rebuilt parts are especially a crap shoot.
 
Shorter or longer? I checked the length of the rod before assembly. The best I could tell is that it was a .010 longer than the book said the range was. I'll give it a try when I get a chance.
 
No slop between the push rid and the MC piston, just bottomed into the piston hole John, and believe me when I tell you that an 8th" of ah turn can make the difference in too much or too little of what you think you've got. Trial and error Pal, Jer
 
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