You didn't say what car this was on, so things may be different. The older cars had single diaphram actuator (Actually 2 diaphrams one top and one bottom, but a single system) while others had dual diaphrams (2 upper, 2 lower). The singles can be rebuilt using the replacement rubbers you found at Perfromance. If you have singles, call Phil at PartShop and see if PartsShoip or FastLane can provide these rubbers. If you have the dual diaphrams you'll have to replace the entire acutator I believe.

The system will only hold vacuum after shut down once the system is completely sealed. I also believe your cruise is vacuum actuated and now that the system is partially closed you are gaining some function.

The cracks you found in the rubber were all on the top, weren't they?

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.