Lockheed Brake Cylinder Rebuild

[Bingster]

I was cleaning up my brake cylinders for my '47 DeSoto and noticed the inside of the cylinder had some pitting near the end of the opening.  I know that re-sleeving would be the ideal fix, but if that isn't in the game I wanted to see if I could rebuild these.

 

Castings are the real deal.  But how much can you hone before the inside diameter gets too wide to make a good fit with the piston?  And are the pistons in the rebuild kits all the same diameter? Is there some standard diameter that fits all cylinders? Based on what? The original cylinders?

 

[desoto1939]

Bingster:  Only so much reaming or the dressing up of the inside of a wheel cylinder can be done. If done too many times the inside get enlarged and the cylinder will leak even after a rebuild.

 

Ammco made a tool that you inserted into the cylinder to let you know if the cylinder has been honed to large. I have one of these tools look at the picture and this one is currently on ebay. The unit can measure from 3/4 upto 1 3/16. very useful tool to have. If the tool  moves after the spacer is inserted into the cyinder then it is time to replace. you push a pin through the red handle inthe hole at the end.  Then insert it in the cylinder should be a snug fit if it rocks back and forth then time to replace.

 

Rich Hartung

 

 

 

[Los_Control]

When I was a kid working at a Texaco gas station, they were teaching me brakes.

We would hone the pits out but we had a cabinet hanging on the wall that had all the different sized rubber cups.

Pretty sure they were in 1/16" increments. ..... I was told to put in 1 size larger cups. so if they were 15/16" I would install 1".

That was our limit .... if it did not seal then we replaced with new.

 

Maybe searching the internet you can find individual sized cups ..... pretty sure today all rebuild kits for that vehicle will have the same sized cups.

Maybe you can find a rebuild kit for a different vehicle that has the size you want ........ Getting into a hassle ....

 

Maybe just order new replacements, keep your original to have re-sleeved when it is more convenient?

[Ivan_B]

If the mirror is gone, you should generally toss it. It's not like these are not available anymore (are they?). Each cylinder has a specific OEM tolerance range, which you should normally be able to look up. The proper way to check the cylinder is with a bore gauge micrometer.