AJS & Matchless Owners Club

In the process of trying to get the Hand oil pump on my AJS K12 to work. First my understanding of how it functions. You push the plunger down and the barrel fills with oil. The spring then forces the plunger back up and the oil above it is forced past the ball of the non return valve.
Well I realised the leather washer on the pump had disintegrated, measured the internal diameter of the pump cylinder and ordered what I thought was the correct sized washer. It was difficult to fit as it seemed too big but with some help and after soaking it in oil for a few days it went on and into the body. But with it all assembled and the body immersed it a fair bit of oil it does not seem to pump.
I am assuming that the leather washer is too tight or too thick and not allowing the oil past to prime it, but am I missing another possible problem that is preventing priming?
Secondly I have a pilgrim pump, which was a possible upgrade extra fitting. What can I do to test it? (the bike is not yet running, after all I have only had it since 1993!)
Thanks in advance

Hello, Clive. The hand pump on my AJS G8 didnt suck up the oil when I got the bike - not that they're needed very often. After much head scratching I found a tiny bit of pitting in the little ball bearing of the one way valve in the 'elbow' of the outlet pipe. It was only spotted with a magnifying loupe. It was enough to disable the pump though. Watch out for the very light spring that holds it against its seat - it can be replaced by a section of ball piont pen spring. Ask me how I know

As for the pilgrim pump, mine wasnt regulating correctly so I took the easy way out and sent it to Pete's Bikes for an overhaul. He charges £80 including return postage - plus any parts needed, but he always checks with you first. He found some cracked parts in mine so a total rebuild is 270 quid But what price is unobtanium and a potential engine rebuild eh?

Steve

Don't forget that the leather washer goes the other way up unlike a bicycle air pump that BLOWS air the oil pump SUCKS oil.

Ah so if the ball does not seal of course it will let air in and so prevent oil going past the valve. I am pretty sure i have the valve in the right way. I will inspect the ball. Its also been dry for at least 30 years.

You may find, Clive, that if you block off the outlet with your finger as you push the pump down it may start sucking the oil into the pump, then take your finger away when you release the pump to see if it pushes oil out. If that gets it working then its a sure sign of an air leak.

Steve

Greybeard wrote: ↑Thu Feb 17, 2022 5:32 pm You may find, Clive, that if you block off the outlet with your finger as you push the pump down it may start sucking the oil into the pump, then take your finger away when you release the pump to see if it pushes oil out. If that gets it working then its a sure sign of an air leak.

Steve

Will give it a try. I do have a second body but the outlet arm is too long but I can see if I can get that one working if the correct shorter one does not.