Oil pressure issue

[Alan K]

Alan, you were correct. I was able to get the screen off. If I can't get a new one, I'll work on getting this one cleaned up. I did get the pan cleaned out. There was a massive amount of sludge in there! Hopefully that will solve this issue.

When I put the adjusting screw back in the oil pump, just wondering if there is a preliminary setting to put it at till I can start the tractor and make the final adjustment?

Are you able to measure your old adjusting screw? If not I could measure the outside amount on one of my ZAs. That should get you fairly close.

 

[T.R.K.]

If you remember where the adjusting screw was before all this issue started, I would put it about there. If in doubt, guess, plus another turn inward or two.
My Cousin, who was around when these tractors were nearly new, showed me you can clean a fine mesh pickup screen on one with a good wire brush. With bristles that are still straight.) You don't side the brush back and forth, you press it into the screen so the bristles go through the holes a little way. Soaking a few hours (or days if you have the time) in solvent doesn't hurt any either. I used a brush with brass bristles.

 

[molinegb]

Best way is to pressure up system and force air out. Take off oil line. Use a transmission gun oil and inject on fitting. Is what I do on all rebuilds. Usually about 1/2 width of lock nut. ( 3 or 4 threads).

 

[buickanddeere]

I may have written about this before. If I did, it must have been before the new software, as I couldn't find anything when I looked back.

On my '49 ZA, when I first started it up last year the oil pressure gauge was bouncing all over the place. I unhooked the line going to the gauge and it squirted oil out when I cranked the tractor over. So I put it in the shop, over winter and replaced the gauge. It showed good pressure when I started it up.

Last week when I started it for the first time this spring it showed good oil pressure, but after running about 15 minutes it gradually started to drop till almost zero. It still ran good--no knocking or anything, but I did shut it down. I tried turning in the adjusting screw on the oil pump, but after about a quarter turn it wouldn't go any further, and the oil pressure did not come up any. I unhooked the line to the gauge and started it up again, and all kinds of oil shot out.

I had converted it to a spin on oil filter the year before all this started. Might that have anything to do with it? I did the same conversion on my R, and it's working fine.

Any ideas? Thanks in advance!

The adjustment screw controls max pressure. It does not control minimum pressure

 

[Rich'sToys]

I don't use any of the filter adapter and never will .

Any particular reason, other than originality?

Got the gaskets ordered. The pickup screen was not available, so will be cleaning up the old one and re-using it.

I also realized the threads on the adjusting screw are messed up and I need to replace it. I have a phillips head machine screw which is long enough. Any reason I can't use that, or do I need to get an original one?

 

[Alan K]

Any particular reason, other than originality?

Got the gaskets ordered. The pickup screen was not available, so will be cleaning up the old one and re-using it.

I also realized the threads on the adjusting screw are messed up and I need to replace it. I have a phillips head machine screw which is long enough. Any reason I can't use that, or do I need to get an original one?

The original is rounded on the interior end. That is the main thing. Most of the originals end up with bad threads as the lead washer that seals them gets into the threads and strips them out.

 

[Rich'sToys]

Update. I did replace the adjusting screw. I took the new one I had and rounded the end so it matched the original.

After getting everything back together, it didn't want to start at first. This led to taking care of some other issues, but finally got it running yesterday. And thankfully, it now has all kinds of oil pressure! I got it adjusted down to about 35 lbs. at fast idle. After the weather warms up, I plan to take it out and get it good and warmed up, then will probably change the oil and filter again. I switched it back to 10w30.

Thanks to everybody for their help and input!