Disapointment

[Mike Golka]

Well the vacuum pump I bought on Ebay arrived yesterday and I got it hook up to test it out. The best I could get as far as vacuum was just over 15 in. HG. I haven't had time to narrow down weather it's leakage or a bad pump. It is a Gast 0523 that pulls 15" quite quickly. I will investigate tonight but was wondering if there are rebuild kits that are easy to install if needed. I have used hard maple to make the spindle adapted and sealed it with several coats of wipeon poly.

[Tim Rinehart]

Mike,
Sorry to hear the 0523 didn't perform as expected. If used, who knows what may have happened, but I suspect you won't have problems getting a rebuild kit from GAST, if it comes to that. The 523 should be good for 24" or so, typically.

Out of curiosity, did you check this value (15" HG) without going through your vacuum adapter and other sources of possible leakage? In other words...just block the hose somehow just after the intake to the pump? And be sure you have clear exhaust flow without excessive restrictions.

If the adapter you made is giving you problems, that may be rectified with some fine-tuning, discussion of how you made it, pics, etc.

[Thom Sturgill]

+1 on the testing. I would start with just a section of hose, 1 tee with the gauge connected. Block the other end with your finger. This will give a good indication of the max the pump will pull. Then add and test each segment to see where you are losing vacuum.

[Steve Schlumpf]

Mike - I suppose the pump could be bad but more than likely you have a leak somewhere. Just break it down into smaller sections and test - you'll find it.

[Ryan Baker]

I agree. It is unlikely that the problem is with the pump. There are a LOT of places where you can easily lose that much vacuum to leaks. Start with just the pump and add the other parts is stages until you find the place (or places) that are leaking. Any wood components need to be sealed very well, as they will leak more than you would think. The rotary adapter and the chuck are the best sources of leaks. I had easily 29" up to the spindle, and a wooden chuck took that down to 10". It was not sealed, but most of the leak was probably at the mounting threads. Keep checking, you will find it.

[Mike Golka]

As a pipefitter by trade I am both happy and sad. I may be getting on in years but I can still make good pipe joints. Tested the pump last night by putting a gauge directly into the pump. The result was no leaks in the system as all the pump could do was pull 15" HG, the same as when the sytem was completely set up. Guess I'll be looking for a rebuild kit:mad:.

[Jerry Pittman]

Mike,
I, too, have a used Gast 523 circa 1992 that pulls about 20-21 in Hg. So I figured that sometime I am going to need parts. I googled Gast and found www.gastmfg.com (http://www.gastmfg.com).
From there I called 269.926.6171 in Benton Harbor MI and got the following info.
a. repair kit for the 523 is # 0523-101Q-G588DX.......K247 @ $58.90 (a year or so ago) and
b. that they have a Chicago area parts house that I can order from; there may be one closer to you however.
HTH,
Jerry

[Tom Godley]

I would give Gast a call -- the guy in the technical department is very helpful. I had a 220v pump that I was going to rebuild -- but I found a new 110v unit.

Many of them have a head with internal filters (two black plastic knobs) -- make sure they are clean -- as well as any exhaust silencer. You probably already looked at those so the vanes are more than likely going in the pump. You can get all the parts from Gast.


They make a lot of different configurations of that pump -- but with all of them you should be getting into the 20's.