So my in one of the milk crates filled with parts, I found a master cylinder rebuild kit. I didn't find any instructions.

I took apart and cleaned the existing master cylinder. Boy, was that thing a mess. It seems pretty straight forward to reassemble. The one thing I botched up the lil checkvalve (resembles a thimble) -- I'm not sure what way that goes back in.

Also, how can I bench test this thing? Is is possible with crude tools? Stone hammer, etc..

I plan on have all the brakes done before I put the cab back on. I could just install it and see how it goes. I have this inevitable feeling that something will be wrong, requiring its complete removal. But thats okay too.

 

Be sure not to use any petroleum based product for cleaning the internal parts as they will contaminate the brake system. I used alcohol the last time I did one but it has been some time ago. I do not remember which way the check valve goes either but be sure to find out as it will not work correctly if the valve is not pointed the right way. You should bench bleed the cylinder before you install it and that should serve as your bench test also...