Oil pressure issue

[Rich'sToys]

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!

 

[J.Wondergem]

Are both oil filters the same number?

 

[Alan K]

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!

If that has the original lead washer on the oil pressure adjusting screw, it may have stopped turning because the lead is pushed into the threads and wouldn't allow it to turn. Had that happen on my dads ZA. Had to take the nut off of the stud and clean it. You may need a new stud if it wore too much on the threads.

 

[Rich'sToys]

Are both oil filters the same number?

They are. When I first did the ZA I had used a different brand-I think I cross referenced the original no. to this one. But then when this issue first came up last year, I replaced it with the proper Wix filter that the instructions called for.

 

[Rich'sToys]

If that has the original lead washer on the oil pressure adjusting screw, it may have stopped turning because the lead is pushed into the threads and wouldn't allow it to turn. Had that happen on my dads ZA. Had to take the nut off of the stud and clean it. You may need a new stud if it wore too much on the threads.

I'll pull that off and check it out. I've never had one of those apart, but I do have a factory service manual for that tractor so hopefully I'll get it figured out.

 

[Rich'sToys]

Update--I removed the adjusting screw and got it loosened up so it turns freely. I also pulled out the springs and check valve and cleaned them up and reinstalled them. Started it up; no oil pressure showing, even with the adjusting screw turned in as far as it would go.
Once again I unhooked the line to the gauge and started it up. This time very little oil came out-only a couple short spurts.
So that's where it's at right now. Not sure what to do next. Open for suggestions.

 

[Alan K]

Update--I removed the adjusting screw and got it loosened up so it turns freely. I also pulled out the springs and check valve and cleaned them up and reinstalled them. Started it up; no oil pressure showing, even with the adjusting screw turned in as far as it would go.
Once again I unhooked the line to the gauge and started it up. This time very little oil came out-only a couple short spurts.
So that's where it's at right now. Not sure what to do next. Open for suggestions.

Only other thing I can think of is if the woodruff key is sheared on the oil pump drive shaft in the oil pump.

 

[sms]

Only other thing I can think of is if the woodruff key is sheared on the oil pump drive shaft in the oil pump.

Had that happen to a tractor that got some water in the crankcase. when it got cold it froze in the pump.

 

[molinegb]

Drop pump off and clean and check for blockage. Check drive gear. Any pump off a Jet,U302 will fit. Filter setup may be bypassing and not building pressure.

 

[T.R.K.]

Did you ever pull the side cover and check the pickup screen for blockage?
Also, it is not unheard of for the woodruff keys to shear in the oil pump drive gear. You have to pull the gear off the shaft to check.

 

[Rich'sToys]

I dropped the pump this afternoon. Tried turning the drive gear and it wouldn't turn, so I'm assuming the keys are not sheared off. I noticed there didn't seem to be a gasket in there, but the parts book calls for one. Not sure what that's about.

I will be pulling the side cover and checking that. Before I do, I want to get a gasket for that also. The parts book shows two different ones--one thick and one thin. Why would that be? Does it matter which one I get? Or do I need to pull it apart first?

 

[molinegb]

Gear clearances are set up with the gasket thickness. Normally just reuse what was on there originally. Take pump apart and thoroughly clean. I don't use any of the filter adapter and never will .

 

[MMDEL]

It is to adjust for backlash for HYDRAULIC PUMP