CJ-3A Master cylinder rebuild..

I bought this 51 CJ-3a on Monday...this is Friday and i've already pulled the engine and have taken it to the machine shop...

This gives me time to work on the brakes and all the other things.

This has a Wagner lockheed master cylinder but what makes it different is that it is an aluminum casting with a metal top, held on with 6 little bolts. I'm told this is original to the late 2A's and early3A's, so I will keep it and rebuild it.

The bore looks good, and is probably fine with just a good cleaning..

My question is, should I hone it, or just give it a good cleaning??




Thanks,

Randy

 

If there is no sign of corrosion or pitting just clean it and go. Inspect it really closely for any sign of bore damage where the seals would ride in normal use. You can't really improve on perfect. It isn't like an engine where you need crosshatch for the rings to seat.

 

Thanks Bill,

It really does look surprisingly good...I'll just clean it up and put a kit in it. Looks as though the standard 1" Lockheed rebuild kit will be what's needed...I can't find one that specifically mentions an aluminum casting. The only item that would not be included would be the gasket for the top..but the old one is not leaking, or at least shows no sign of having leaked, so I may just leave well enough alone....or it would be easy enough to make one...

Randy

 

I would hone it if there are no pits.

 

That is correct for an early 3A.

 

Does the bore have a steel liner? If it's an aluminum bore, you cannot hone it with stones. The aluminum will fill the pores in the stones and ruin them.

If it's steel lined, look for pits in the bottom of the bore. Water in the brake fluid pools in the bore, and corrodes it at the bottom.

 

Thanks Tim,

I'll see if I can tell...it is one consistent color throughout so I'm thinking it is all aluminum...I'll give it a good going over...

 

Magnet.

 

It's aluminum...

Thanks Tim!

 

Well I just sent it off to Apple Hydraulics for a sleeve....I'm replacing all the wheel cylinders, lines and shoes...might as well just go all the way.....