1957 power brake booster leak

[curtkane]

I am loosing a little brake fluid. Check all over and see no visible leaks. Suspect it is at the power booster. Being sucked into the engine and burned. Would a rebuild kit solve the issue.

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[lcboyer]

A master cylinder can be rebuilt. It’s usually necessary to hone the cylinder before installing new components. If you already own a brake cylinder hone. Or know where to borrow one. It’s cheaper to rebuild.

 

[curtkane]

I'm thinking more like the power boost unit

 

[Tom Alpers]

I'm thinking more like the power boost unit

Yes, if you see no fluid leaking it's probably internal. The booster "can" can hold a lot of fluid. You can buy rebuild kits from Harmon Brake. Here's a video showing what's in there.

 

[74 Harley]

I'm thinking more like the power boost unit

The booster doesn't contain any fluid, it there's any in it then it came from the master cylinder.

 

[83ragtop50]

The booster doesn't contain any fluid, it there's any in it then it came from the master cylinder.

The booster is a separate unit mounted separately on the inner fender well; it is not integral with the master cylinder as in later models. The brake fluid is routed to the booster via a regular brake line where the "boost" is applied.

Is there any evidence of fluid in proximity to the booster? Have you checked the wheel cylinders?

 

[curtkane]

Yes, check wheell cylinders brack lines and master cylinder. Disconnecter vacuum line going to booster and plugged it. Don't see fluid lose and brakes just a lttle harder.