Vacuum pump "bounce"?

[flewbyu]

I understand the vacuum pump should pull down 20-25" Hg at idle. When I tested mine the needle was bouncing too bad to read. It jumped around approx 16-18" Hg with a swing of about 4-6". Is this normal?

 

[Westech]

yes.. its a diaphragm pump.

 

[flewbyu]

Understood, thanks!

 

[Westech]

 

[flewbyu]

Anyone have a source for these pumps? I think mine is on the way out, and need a new or good used one. Thanks in advance.

 

[mtjbrown]

Autozone has them as a rebuilt unit. No idea how well they work.

 

[Westech]

I got mine from Oriley for 100 bucks or so... life time warranty.

 

[m38inmaine]

Napa has them also, just over $100, or flmv.net has nos units but cost a little more than a rebuild.

 

[oldmechanic]

I have a used one $50+ ship
Cecil

 

[raiburn]

New on Epay for $150