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General Information => FAQ/Tech Tips/Please Read First => Topic started by: 8v-of-fury on January 07, 2013, 11:58:01 am

Title: Rotary Vacuum Pump Repair
Post by: 8v-of-fury on January 07, 2013, 11:58:01 am
FAQ'd for awesomeness.  ;D

I've fixed rotary vac pumps by pulling the lid, driving out the remnants of the stock check valve, tapping the lid to 1/8 NPT making sure to chamfer the edges so the vanes don't catch and installing one of these check valves (http://www.mcmaster.com/#7775K21).  Be sure that when you tap the lid you don't tap so far that the check valve will protrude past the lid.  I then used a 1/2" barb fitting (I cut it off a fitting I had on hand), tapped it to 1/8"NPT and attached it to the check valve.  It works perfectly and is an upgrade from the stock piece in being much more robust.

(http://i13.photobucket.com/albums/a269/libbybapa/100_1850.jpg)

 
Title: Re: Rotary Vacuum Pump Repair
Post by: bbob203 on January 07, 2013, 12:18:34 pm
Thanks Needed This!!!
Title: Re: Rotary Vacuum Pump Repair
Post by: shortysclimbin on April 09, 2015, 04:58:54 pm
Has anyone found the vanes to replace the inside bits yet?  I have one with melted pieces....
Title: Re: Rotary Vacuum Pump Repair
Post by: theman53 on April 10, 2015, 08:35:15 am
I have not, but I am guessing you could find a suitable plastic and make your own.
Title: Re: Rotary Vacuum Pump Repair
Post by: shortysclimbin on April 10, 2015, 09:29:05 am
That was my next step if I couldn't find precept replacements.
Title: Re: Rotary Vacuum Pump Repair
Post by: TylerDurden on April 10, 2015, 11:45:26 am
I rekon the originals were phenolic resin.

If the pump got hot enough to melt the vanes, it probably ran dry and may have other issues.

Chime back if you need dimensions on those vanes.
Title: Re: Rotary Vacuum Pump Repair
Post by: fatmobile on April 12, 2015, 10:16:31 pm
I think the picture posted doesn't have a check valve.
Title: Re: Rotary Vacuum Pump Repair
Post by: theman53 on April 13, 2015, 09:00:56 am
I think the picture posted doesn't have a check valve.

No, that was the reason for faq ing the pic. It does have one installed. See the print in the picture.
Title: Re: Rotary Vacuum Pump Repair
Post by: libbydiesel on April 13, 2015, 11:22:55 am
Yeah there's a check valve installed.  There's a link to McMaster in the quoted text.  $12.