1941 Cadillac Series 63 Sedan Master Cylinder Leak

[J. Russo]

Can anyone tell me if this can be repaired? I have attached some photos that show the diagram of the type of master cylinder I have as well as where I have a leak in the back of the reservoir.  There is a round indentation where fluid is seeping through. The diagram doesn't show a part in the area that is leaking. Thank you

[Jim Miller]

If you are not concerned with authenticity, consider a bracket from Art Gardner that holds a Wilwood dual master cylinder. Art's bracket fits in perfectly on the 41 and you gain the safety of a dual system. Worked great for me.

[Brad Ipsen CLC #737]

That is a casting core plug just like in an engine which in that case is sometimes called a freeze plug.  This is a cup that is expanded in a hole machined in the casting.  To replace you would have to take everything apart and typically would replace the seals, etc. all at the same time.  Also sleeve the cylinder if required.  Or as an alternate buy a complete new master cylinder which I believe are available.

[Jay Friedman]

If you can't get a Gardner/Wilwood Dual Master Cylinder kit, best thing is to have it rebuilt and sleeved with either brass or stainless steel.  Best places to do this are White Post Restorations or Hagen's HiWay Auto Parts in Wash. state.