Thread: Problem with lathe oil pump

Originally Posted by GuzziJohn

I was planning to drain the oil and try flushing the pump with kero.

Is this likely to harm the pump in any way? If there's something else to try I'm open to ideas.

John

I wouldn't use kero as it's a poor lubricant.

I would use diesel fuel as it has a lubrication factor for injector pumps etc. I've flushed truck gearboxes with this once or twice where required.

Can you blow compressed air through the system?

The problem could also be wear related.

Cheers

Rob

My Jafo mill had a problem where the oil pump on it would not pump...

The mill had not been used for decades prior to me getting it and the problem was rust in the oil pump...

It had a ball bearing running in a tube, and for forward the ball moves to one end to block an end off, for reverse it got pushed to the other end of the tube...

Some minor rust and the ball was stuck...

Originally Posted by nearnexus

I wouldn't use kero as it's a poor lubricant.

I would use diesel fuel as it has a lubrication factor for injector pumps etc. I've flushed truck gearboxes with this once or twice where required.

Can you blow compressed air through the system?

The problem could also be wear related.

Cheers

Rob

Hi Rob.
I'll give the diesel flush a go tomorrow.

I think I would need to get to the suction side of the pump to try using compressed air.
Once I get the oil drained I will be able to see if this is possible.

If the pump is indeed worn then things will be a lot more complicated.

Originally Posted by .RC.

My Jafo mill had a problem where the oil pump on it would not pump...

The mill had not been used for decades prior to me getting it and the problem was rust in the oil pump...

It had a ball bearing running in a tube, and for forward the ball moves to one end to block an end off, for reverse it got pushed to the other end of the tube...

Some minor rust and the ball was stuck...

Hi Richard.
There must be some valve arrangement to allow pumping in either direction.
Hopefully it is just some crud causing one of the valves to stick sometimes.
A drain and a flush and I'll see what happens.

John

Today I drained the oil and flushed the pump with some diesel as suggested by Rob.

I then washed the internal surfaces down with some kero just to give it a clean while I had the top off.

As I had feared, removing the pump would require someone with hands quite a bit smaller than mine or some extra dis-assembly to improve access.
I would need to remove the inlet and discharge fittings and then I think it should slide out.

Pump performance seems ok with the diesel when turning the chuck manually so I will refill with oil and see how it goes.

Any idea what oil I should use? Hydraulic oil I assume but what viscosity. There is no recommended lubricant data on the lathe.

JohnPump 3.jpgPump 2.jpgPump 1.jpg

Hello GuzziJohn,
Guess it doesn't freeze in Rockhampton, so a regular ISO 68 grade hydraulic oil should be fine. One containing a zinc additive would be a bonus, but not essential. Combustor.

Originally Posted by Combustor

Hello GuzziJohn,
Guess it doesn't freeze in Rockhampton, so a regular ISO 68 grade hydraulic oil should be fine. One containing a zinc additive would be a bonus, but not essential. Combustor.

Thanks for the advice.

I'll see If I can track some down today.

John