Master cylinder

polara383500

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Master cylinder is leaking out the top by the gasket! What’s the best fix a new master cylinder or try to find a new lid and gasket? I looked for a new seal but can’t find one!
 

CBODY67

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Is the rubber seal ballooned? Pushing brake fluid out past anything in its way? Reason I ask is that if the wrong fluid was put into the system, the rubber master cyl seal expands greatly and usually leaks a bit in the process.

Might check on the local auto supply store's "HELP!" rack of parts or possibly the Dorman website itself. Single cyl or the later model dual-circuit master cyl?

Just some thoughts,
CBODY67
 

mrs49

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Master cylinder is leaking out the top by the gasket! What’s the best fix a new master cylinder or try to find a new lid and gasket? I looked for a new seal but can’t find one!
Put the gasket in a thick baggie, install and trim. Worked on my Harley 20 plus years ago.
 

polara383500

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Is the rubber seal ballooned? Pushing brake fluid out past anything in its way? Reason I ask is that if the wrong fluid was put into the system, the rubber master cyl seal expands greatly and usually leaks a bit in the process.

Might check on the local auto supply store's "HELP!" rack of parts or possibly the Dorman website itself. Single cyl or the later model dual-circuit master cyl?

Just some thoughts,
CBODY67
It’s dual! No the rubber is always fine when I take the cover off!
 

polara383500

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05391BAF-3642-4631-9CC9-224EE17EDDA7.jpeg
 

Big_John

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It seems to me that you have one of three things wrong... Covers bent, gasket is bad, or the master cylinder is in bad shape where the gasket seals to.

So, you can replace the cover, seal, or MC. Finding a good cover or gasket means hoping someone has an old one laying around... Or if they have a new one, bet it's not much less than the price of a new MC.

By the time you get all done, you can buy another MC and be done with it.
 

polara383500

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It seems to me that you have one of three things wrong... Covers bent, gasket is bad, or the master cylinder is in bad shape where the gasket seals to.

So, you can replace the cover, seal, or MC. Finding a good cover or gasket means hoping someone has an old one laying around... Or if they have a new one, bet it's not much less than the price of a new MC.

By the time you get all done, you can buy another MC and be done with it.
When I bought the car it said it was replaced but that don’t mean nothing! I might change it over in the winter when she’s parked!
 

polara383500

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Can you upgrade the master cylinder to a Wilwood or something like that? When I look for replacements it’s hard to find them!
 

Big_John

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Can you upgrade the master cylinder to a Wilwood or something like that? When I look for replacements it’s hard to find them!
Why do that? No advantage at all except having some bastard piece that you have to probably change line fittings to make work.

Those master cylinders are easy to get. Try Rock Auto
 

polara383500

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Rock auto or nobody had a
Why do that? No advantage at all except having some bastard piece that you have to probably change line fittings to make work.

Those master cylinders are easy to get. Try Rock Auto
Why do that? No advantage at all except having some bastard piece that you have to probably change line fittings to make work.

Those master cylinders are easy to get. Try Rock Auto
rock auto or nobody else has disc and drum master cylinders! Just drum and drum
 

PH27L7

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rock auto or nobody else has disc and drum master cylinders! Just drum and drum
IMHO not correct...
More Information for CENTRIC 13063047

I should have a spare cover & gasket lying around if you want to go that route. Before you do that though you should inspect the sealing surface to make sure there are no imperfections that would cause the leak.
 

CBODY67

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IF you want a Wilwood master cyl, you'll probably need the entire Wilwood disc brake conversion kit to go with it . . . as a matched set. There should be an OEM m/cyl available for you with disc/drum brakes, probably all the way to at least the 1973 model year C-body cars. starting with 1967 applications. LOTS of useage, it would seem.
 

Imperial dude

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How tight is the bail?
I had the exact same problem, took the rubber out, cleaned the rubber, lid, mating surface on the master cylinder, and bent the bail so it fit tighter and never had the problem again
 

polara383500

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How tight is the bail?
I had the exact same problem, took the rubber out, cleaned the rubber, lid, mating surface on the master cylinder, and bent the bail so it fit tighter and never had the problem again
I’ll try that
 
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