It also could be short cycling which is cause by a bad check value in the pump or a vacuum valve that is plug into your vacuum brake booster if you have one.
To prevent this short cycling, I had to install a vacuum canister in the out put line of the vacuum pump. Install a vacuum brake booster check valve on both sides of the vacuum canister which are the same type that plugs into the vacuum brake booster. OR you could put it on continuous run. My pump is a standard pump use for a diesel engine that is built driven. It only has that click noise on start up which is cause by the check valve which fully closes when the vacuum gets up to 15 in.hg. I normally run at 20 to 22 in.hg with no vacuum noise while the motor is turning. When the motor stops, the two addition check valves on both sides of the vacuum canister which prevents the vacuum to bleed back to the pump. This work good for 16 years until my vacuum brake booster would not hold any vacuum any longer. I replace the vacuum booster with a hydra brake booster that does not use any vacuum, just hydraulic oil pressure from the power steering pump. There is a WEB site that shows how to do this conversion call - Hydro Brake Booster Conversion - giving a photo step by step and how to do this. Roland ----- Original Message ----- From: Adrian DeLeon<mailto:[email protected]> To: [email protected]<mailto:[email protected]> Sent: Friday, September 27, 2013 2:36 PM Subject: [EVDL] Vacuum pump question/issue I've got a 7 year old MES-DEA vacuum pump that no longer shuts completely off. After pumping down, the pump begins to quit, but then starts/stops rapidly, sounding like the lope of an idling (very quiet) race car engine. I checked for vacuum leaks, disconnected and plugged various hose ends, and finally plugged the end of the pump with my finger. In all cases, the pump would stutter after reaching its preset vacuum level. Now for the big question: Do I leave it the way it is? Or do I put the pump into its "continuous run" mode? My thought is that running constantly would be better than the constant start/stop, which is probably stressful to the motor and its drive electronics. This particular model has a built-in pressure sensor that gets bypassed if the polarity of the pump connections are reversed. Ideas? Adrian _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub<http://www.evdl.org/help/index.html#usub> http://lists.evdl.org/listinfo.cgi/ev-evdl.org<http://lists.evdl.org/listinfo.cgi/ev-evdl.org> For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA<http://groups.yahoo.com/group/NEDRA>) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130927/f361c12e/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
