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Edwards pump

Posted: Wed Aug 27, 2008 6:10 pm
by gary_f
My Edwards E2M2 pump suddenly went from 3 micron to 200 micron. Anyone have experience with this pump? Straightforward? Seals? Special tools needed? Thousands of parts ready to fly out when I open the case?

I looked at some of the old posts on repair but didn't see anything for this pump.

Re: Edwards pump

Posted: Thu Aug 28, 2008 7:26 am
by DaveC
Could be something mechanical, but if the pump is still making normal noises, and not leaking oil somewhere, and the belt's tight, then I would be more inclined to think... low or contaiminated pump oil. One assumes all the other vacuum connections are checked and good.

Try running it for a while (15 min), with the gas ballast wide open... then close the ballast, quickly to see if the pressure drops somewhat. If you have volatiles in the oil, (water, or solvents) the pressure will first drop and then creep back up again.

You could invest a few hrs in operating with ballast open... to gradually work out the contamination,....or take the shortcut and drain the oil, and replace with fresh.

If the above makes no change from the outset, then there is something else wrong.. A seal leak is next most plausible. For that you need a rebuild kit for your specific pump.

I wouldn't recommend opening up the pump, without a service manual's parts list and an assembly diagram..

Dave Cooper