Re: Bendix Treadle Vac Study- Serioius Business!!

Posted by HH56 On 2011/6/7 11:21:54

IMHO, BTVs are a bit more sensitive than other or more modern systems if that is what you are comparing them to but can't say I remember anyone mentioning the problem you have. If there is no grease or fluid on the linings making them grab, then possibly one of the rubber poppets in the vacuum section has dried or needs attention and the power unit is only working all on or all off instead of proportional to pressure.

Other than cleaning the piston and can, I don't believe rebuilders typically mess with anything in the inner vacuum side because it usually needs relatively little attention and there are no new rebuild kit parts I know of. If it's the same unit you had rebuilt with same problem, Ross has mentioned checking for dried or hardened rubber seals on the vacuum side valves and a method for replacing if any is found. He might have a better idea if the symptom you mention could be caused by a dried rubber part. If you have had more than one rebuilt unit exchanged with the same symptom, then I would look for something external to BTV such as linings.