How to Test Grover Air Pump

[glang58]

Posted a few days ago about the fuse size for my Grover Air pump in my '60 Overlander. I'm going through my water system and everyone's help was appreciated.

Now I have another question. I disassembled the pump, cleaned everything, reassembled and filled with 20wt oil to bottom of fill opening as instructed on other threads. Pump runs great, but I can't feel it pushing any air from the lines. I disconnected the air line at the top of the piston housing and can't feel air moving when the pump is running. Any ideas on what might be happening or how to test for proper air flow? The pump seems to be working great but I don't want to put everything back together until I'm sure it's moving air. Thanks in advance. Couldn't keep up with this old thing without you guys! BTW, I also have a Univolt question that I'll be posting in a separate thread.

[Rebee]

I am not familure with your particular pump but I know a little about pumps in general. If it were mine, First I would hold the output line shut and see if air is being pushed back out the intake.This will show a bad flapper or other device which prevents back flow. If no back flow, then I would take a little, and I stress little, heavy oil, 90 wt. Put a vew drops in the piston chamber. Enough drops to make a seal around the piston. This will tell if the piston is worn out. If the output air increases then a worn piston is the problem. I must say again, this is what I would do if it were mine to locate the problem. Ihave no knowledge of how to get it rebuilt.