Gast vacuum pump question

[Tom Davis]

I have built a vacuum system for my wife using the following components:

Gast 0523-504Q-G18DX pump (used)
JT Turning Tool vacuum manifold and adapter

I can only get 15 hg of vacuum. All tubing and connections seem to be secure. Should I expect more? If so, where do I start troubleshooting?

Thanks for any comments.

Tom

[Steve Schlumpf]

Tom, when troubleshooting vacuum - like anything else you have to break it down into sections if you suspect you have a leak. I would attach the gauge directly to the pump and see what it can draw as a max. You said the pump was used... so how used would be a valid question. The pump uses graphite vanes and they do wear out. I haven't done it to my pump yet but know they offer rebuild kits - if/when needed.

[John Thorson]

I have exactly the same setup and have gotten used to cleaning the internal filters every few months. Also check the o-rings on the JT adapter. You should be able to pull 29" with this machine and over 20" in real use unless the wood is very porous.

[Tom Davis]

Thanks for the suggestions. I mounted the guage directly to the pump a nd still got the same 15" reading. I will get the rebuild kit and try that.

[John King]

Thanks for the suggestions. I mounted the guage directly to the pump a nd still got the same 15" reading. I will get the rebuild kit and try that.

Tom - I have same pump. Considering rebuild to improve performance. Please post info on source and cost for rebuild kit. Thanks! - John

[Steve Schlumpf]

Tom, spend some time Googling available rebuild kits. There are a number of them out there. Here are just a couple. Good luck with your rebuild!
http://gopro.pro/Gast_K478_Repair_Kit.htm
http://www.septictankparts.com/Pump-Rebuild-Kits/K478-Vane-Kit-For-Gast-0523-Rotary-Vane-Air-Compressor.html

[Joe Bradshaw]

Tom, the re-build kits are the way to go. I had the same problem and the kit fixed mine. About a 20 minute job. Good luck.
Joe

[Larry Komroff]

Tom, make sure the filters with o-rings in the end of the vacuum head are sealing. If not you can loose vacuum there.

[Sparky Paessler]

I have the 0522 pump and it's vanes were fairly worn down. It would only pull about 20". I ordered new vanes and it now pulls 27.5 which for my elevation is pretty good. (I'm at 1680 feet. Makes a difference on how many inches you can pull!). I think I paided about $50 for the new vanes which is the main thing in the rebuild kits. I got mine from
http://cfpwarehouse.com/shopsite_sc/store/html/gast_vanes.html
They were great to work with. Turns out there were two different sizes vanes for the 0522 series and I got the wrong ones at first. They contacted Gast and found out which were the right ones for my pump and got them to me. At $12.65 a vane it was the best price I found. Not connected to them in any was except as a happy customer.

[Tom Davis]

I ordered the kit from GoPro. I'll post the results.

Thanks guys

[Tom Davis]

Update:

I received the rebuild kit today. It was about a 15 minute install and the pump now pulls 27" of vacuum compared to 15" before the rebuild.

I could've saved $15 or $20 by purchasing just the vanes as suggested by Sparky but the gasket broke apart when I took the pump apart, so the kit worked out better for me.

Thanks for the help.

Tom

[Steve Schlumpf]

Happy to hear that the rebuild kit worked out! Looking forward to seeing some turnings!!