The GMC CCKW

Hi all,

At the moment I'm restoring with friends a 7 tons semi trailer which was pulled by a Studebaker US6x4. The trailer is equipped with vacuum brakes. Original the brakes were made by Bendix. We have the following problem. We're missing the conversion valve of the trailer.
My question is if someone knows who has such a valve or a manufacture that is still producing these kinds of valves? I tried PBR in Australia who still making this type of valve but this company is not responding to any of mine mails. Is there another manufacturer of these valves or does someone knows a place were I can find a conversion valve? The model which was made by Bendix was called SPC-PC and the complete system had the name Bendix BK vacuum according to the manuel.

Hopefully someone has a solution.

Best regards,
Paul Hazen

The manual is at:

http://www.ibiblio.net/hyperwar/USA/ref ... _9_882.PDF

Thanks for the link, I've found the same manual once on a other site. Not many of these trailers are restored. We were lucky enough to find a relative complete one. The valve is the only missing item at this moment. The trailer was converted by the Belguim army to air-brakes.

I actually think you can use it w/o the valve. If the control line is connected directly to the vaccume cans. It would probably just be a little slow releasing.

I have a 1948 Ford road tractor with a1948 Freuhauf semi trailer with vacuum brakes. I had to change the trailer brakes from air to vacuum. There is a company called Velvac that supplied all the parts to convert the system. They had the converter valve, but that was about 15 years ago. I'm sure they are still in business. You can check the www.