B-K Vacuum Power Brakes, ’36-’38

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Regarding PASB 2019-1; the “Air-Suspended” type cylinder used in ’36-’38 Pierces is, in fact, repairable. I overhauled/restored mine in 1992 and it is functioning just fine. I intend to write a PASB article on that effort, but need a little help from “experts” among us.

I have been unsuccessful in determining the correct lubricant for the leather piston cup. There are lots of opinions out there, but before I land on the best product available today, I would like some verifiable technical data. Anyone have published literature/articles on this subject? Peer-reviewed journal pubs? Textbook entries? Whatever?

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Neatsfoot oil…………now you have to go out and kill a neat and cut off it’s feet to properly service your car. 👍

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I think that some additional comments on PASB 2019-1 are in order, for the benefit of anyone contemplating repairs to their B-K Vacuum Power Brake system:

1. A dash mounted vacuum gauge is not OEM on PA’s and would be considered not “authentic” for judging purposes. As would be the tee fitting, modern compression tubing fitting and incorrect hose clamp.

2. The correct hose size would be 1/2″.

3. The pictured check valve is correct for only 1936. !937-38 valve use a two-bolt rubber mount, which is not available from Steele.

4. Adding lube via the vacuum hose fitting is not correct. One of the four front plate mounting bolt-holes is drilled thru to the interior (the other three are blind holes). Removal of that bolt allows the addition of lube to the correct side of the leather cup.

5. The use of inner tube rubber for the control valve diaphragm is not correct and is likely to fail. The 10psi pressure is too much for unsupported inner tube rubber. The diaphragm must be a fabric reinforced material, which is available from Karp’s Power Brake, Upland, CA.

Hope this is of some help.

Bob

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I have asked this before and got no response. Does anyone have info on the OEM trailer hitch used by PA for the Travelodge and/or info on the vacuum connection to the tow car for the trailer brakes?

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