Rotary Vacuum Pump Repair

[8v-of-fury]

FAQ'd for awesomeness. 

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.  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.



 

[bbob203]

Thanks Needed This!!!

[shortysclimbin]

Has anyone found the vanes to replace the inside bits yet?  I have one with melted pieces....

[theman53]

I have not, but I am guessing you could find a suitable plastic and make your own.

[shortysclimbin]

That was my next step if I couldn't find precept replacements.

[TylerDurden]

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.

[fatmobile]

I think the picture posted doesn't have a check valve.

[theman53]

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.

[libbydiesel]

Yeah there's a check valve installed.  There's a link to McMaster in the quoted text.  $12.