Assistance Requested: Mityvac repair

[tam]

Hi guys,

I've recently started a part time gig at my college as the evening tool room attendant. Along with my other duties, I'm to repair tools in my "free" time. I have replaced all of the seals on an old mightyvac hand pump but there is one that I can't figure out how to replace. It's the large one in this photo album: http://imgur.com/a/UNe0b#0

I believe it's the diaphragm for the gauge. I can't figure how to get the gauge apart to make the repair. How does one remove the face without damaging it? I can get the unit to 21 inches of vacuum then it slowly leaks back to zero. Any help would be greatly appreciated. Thanks in advance!

Tam

Edit: I'm a bonehead, this is the pump in question: http://imgur.com/8a0Ep7n

 

[gungatim]

not sure what you're trying to accomplish, the rebuild kit is available, here is a link to the parts breakdown and instructions

http://www.mityvac.com/user_manuals/mvm8900manual.pdf

if the guage is bad, you toss it and buy a new guage. No replacing parts of the guage.

In my experience, if it's a the aluminum bodied silverline, those mityvac's are destined for the scrap bin when they go bad. everyone i've tried to fix the aluminum is corroded and won't seal, and the rebuild kits cost twice as much as the others. the plastic ones seem to fare better, but it's still cheaper to buy a couple HF's for the cost of a rebuild.

 

[Dust Devil]

Rebuilding a hand pump??

Waste of money and time (time is money too).

 

[tam]

The school already had the rebuild kits on hand so I thought I would give it a go. Thank you for the advice/information. I'm still wondering what the large seal is for since it doesn't fit anywhere else, but that's neither here nor there. I was wondering (personally) about the quality of the plastic pump and you guys have helped me answer that question too! Thanks again!

 

[Dust Devil]

The plastic ones are sweet............until you drop it. Once. Gone.