SP 11 drop in vacuum

[gmcooper]

My old SP11 vacuum pump has an issue as I can barely get 5" deadheaded. This unit used to get 20" 2 years ago the last season I ran it. Any ideas on what it would be? It sounds normal for this pump. Belt might be a tad loose but does not seem to slip and does not appear to change rpms when deadheaded.
Thanks
Mark

[dave15]

Possible bad rings. I had one that the belt was slipping on and it was hard to notice, so double check that first. When the horizontal gear goes out, the pump will just push air in and out, so you will not get any vacuum. Let me know what you find, I have a "parts" pump.

[BreezyHill]

could be as simple as debris in the rotary head not allowing the pistons to properly discharge the air...Does it have a timing selector knob on the top that is not position correctly?
If it started the season fine then went to crap this is not good but if it started poor then there is a relatively simple fix...usully something got in it. I had one that a mouse got in and died in the rotary head. Lucky for me it was dried and no oder any longer and blew out the parts with the compressor, timed it and buttoned her up and she was fine again.

Good Luck

Ben

[jetdoc]

I just had a RV-2 Piston stop working and as Dave15 mentioned about the gear going out is true that is what went wrong with mine. Now we are looking for new gears for the pump. Best little pump we had (only). Not sure if we will just find the gears but may need to look for another pump for parts.

[dave15]

jetdoc, if you ever find a source for the gear, let me know. I was thinking about having them made but will need to have several made to make it worth while.

[jetdoc]

I will let you know if I find something. It may be awhile.

[gmcooper]

This pump started out with low vacuum which I thought was from leaks till I started checking everything. That's when I discovered pump was not pulling hardly any vacuum. pump turns ok had flushed pump and refilled oil with no change. Brought in different sp-11 used the same motor and 26" vacuum at releaser. Will tear down pump head when I get a chance most likely after season.