The engine had been running, not sure where there is a reserve vacuum tank though.

It may have a vacuum leak, because, thinking about it, I am not sure the vacuum tube under the dash for the speedo adapter is plugged. I think it may be open. What you are saying is, the vacuum-shifted rear needs vacuum to keep it in gear? (or at least in high gear?) I am not 100% sure whether it was in low or hi. ONe of the vacuum lines was off the truck when I got it and I noticed the metal tube on the rear was full of mud! I cleaned it out with an awl and stuck the vacuum line back on it. I will be checking it out some more. Thanks.


Mike
1955 Chevy 6400 ex-flatbed (no bed now!) sold September 2023
In the Stovebolt Gallery
1958 Chevy 6400 flatbed W/dump
In the Stovebolt Gallery
1959 Chevy Suburban Owned for almost 20 years, Daily Driver -- sold May 2016
In the Stovebolt Gallery

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