high oil pressure

[swhockett]

After replacing the timing gear, valves, new head gasket and carb rebuild the tractor starts and runs great. The oil pressure however starts at close to 80 and drops to the 55 range after warming up. I've tried removing the cap on oil filler tube but pressure remains high (30 is the normal range?). I did notice at the bottom of the filler tube there is clear liquid but the dipstick oil looks normal. The liquid in the tube doesnt have an antifreeze sweet smell nor does the exhaust. Appreciate some help here.

 

[TheOldHokie]

(quoted from post at 14:11:49 10/27/18) After replacing the timing gear, valves, new head gasket and carb rebuild the tractor starts and runs great. The oil pressure however starts at close to 80 and drops to the 55 range after warming up. I've tried removing the cap on oil filler tube but pressure remains high (30 is the normal range?). I did notice at the bottom of the filler tube there is clear liquid but the dipstick oil looks normal. The liquid in the tube doesnt have an antifreeze sweet smell nor does the exhaust. Appreciate some help here.

The filler cap has absolutely nothing to do with engine oil pressure.

I'd start by double checking the pressure with another gauge.

What was the oil pressure before you did the engine work and was it the same gauge?

TOH

 

[R Geiger]

What you have in the filler tube is condensation, run it long enough and it will burn it out.

 

[swhockett]

It would run in the 40 range. Never would start at
the 80. The same gauge but I did replace the wiring
harness.

 

[Bruce (VA)]

Unless you have an electric sending unit, replacing the wiring harness has nothing to do with your oil pressure. OEM is mechanical. 80 lbs of oil pressure is unusual. As TOH said check the gauge.
75 tips

 

[TheOldHokie]

(quoted from post at 14:58:02 10/27/18) It would run in the 40 range. Never would start at
the 80. The same gauge but I did replace the wiring
harness.

That is still on the high side but reasonable. In fact 55 is OK if that is in fact the actual pressure. You really need to double check the accuracy of the gauge before getting to concerned.

The cold oil pressure is limited by the over pressure relief valve which should limit pressure to 55-60 PSI. That valve is in the timing cover which you removed. Did you disassemble that valve or possibly clog the inlet with gasket sealer????

TOH

 

[swhockett]

I replaced the spring in the relief valve. I was pretty
careful with the sealer so I doubt if it is the problem.
Without replacing the gauge what's the procedure
on testing the existing one for accuracy? Thanks for
your help with this!

 

[Bob]

(quoted from post at 14:54:36 10/27/18) I replaced the spring in the relief valve. I was pretty
careful with the sealer so I doubt if it is the problem.
Without replacing the gauge what's the procedure
on testing the existing one for accuracy? Thanks for
your help with this!

You wrote "I replaced the spring in the relief valve.".

Does that mean you were careful to reinstall the original spring in the correct position", or "I replaced the original spring with an new aftermarket spring (likely from "The Land of Almost Right")?

If you mean the latter, it's pretty obvious what's happened.

 

[TheOldHokie]

(quoted from post at 15:54:36 10/27/18) I replaced the spring in the relief valve. I was pretty
careful with the sealer so I doubt if it is the problem.
Without replacing the gauge what's the procedure
on testing the existing one for accuracy? Thanks for
your help with this!

Put the old spring back in - my guess is your oil pressure returns to previous levels.

TOH

 

[swhockett]

Thanks to all. Unfortunately I replaced the original
spring. Hopefully it's among my saved parts.

 

[TheOldHokie]

(quoted from post at 17:39:19 10/27/18) Thanks to all. Unfortunately I replaced the original
spring. Hopefully it's among my saved parts.

To check an oil pressure relief spring:

2.75/2.88 pounds (44/46 ounces) @ 1.8" compressed length.

Replace if outside that range

TOH

 

[Jim L WA]

You never said, but I wonder what weight oil are you running?

 

[Eman85]

Lots of questions. Why did you replace the spring? Did you think there was a problem? What sealer are you talking about and where did you use it? Is the gauge a mechanical gauge or an electric gauge?
To answer your question about checking a gauge you either have to apply a known pressure to it and see what it reads if it's mechanical. Or use a known good gauge and compare.

 

[Hobo,NC]

I installed a new spring while rebuilding my 50 N it had 90 lbs of OP... I put the old spring back in it all was good, CNH has the correct spring.

Few can boast their N can make that kind of pressure probably because it can't even with a stiff aftermarket relief spring... Change the spring and be proud yours can...

 

[swhockett]

Thanks for all help and comments. My gear and
valve job couldn't have been done w/o this forum.
Just to answer the questions, I replaced spring
thinking I was being proactive. I'm pretty sure I used
40 wt oil. The sealant was brushed on in thin layer
on both sides of the gasket. I believe it was made
by Duplex ? Tractor is at farm so I'm working from
memory.