[phpBB Debug] PHP Warning: in file [ROOT]/includes/functions.php on line 4493: ob_start(): output handler 'ob_gzhandler' conflicts with 'zlib output compression'
Farmall Cub • View topic - To much oil pressure?

To much oil pressure?

Sun Nov 28, 2010 2:17 pm

A little history on this tractor. I bought this tractor a year this last Setp. with the pistons stuck and some valves. Got it freed up and running I pushed snow and mowed about all summer with the hood off and could watch my oil pressure at all times. I try and check the pressure every time I start and just before I shut it off. When first stared by the gauge it would run a strong 60#(high rpm) max and warm 20# at idle. Plowed garden last week and parked when done. Yesterday went to take the plow off and when started the gauge was to the far right as far as it would go (75+) at idle and oil started coming out of the oil filter. Never that high before not even close. What do you think?
Ron in Mid Missouri

Re: To much oil pressure?

Sun Nov 28, 2010 3:48 pm

The oil pressure sending unit is behind the lower radiator hose (lower right). If it were I, I'd drain out the oil and filter canister, put some kerosene in the crankcase and spin it with the hand crank Might not even be a bad idea to drop the pan and clean the oil pickup screen while you're at it. Remember oil capacity is only 3 quarts so don't overfill. Good luck. Craig

Re: To much oil pressure?

Sun Nov 28, 2010 3:53 pm

I would pull the oil pressure relief valve and spring assembly and make sure that is not stuck. It is the big nut right under the governor. Clean the area before you take is off so no dirt gets into the oil gallery. There will be the special nut, a spring, and a cup that seats in the block. The gauge could also be bad. Try swapping with another one.

I am not fan of recommending putting kerosene in a crankcase. Someone ran an engine like that and destroyed it. I know Craig did not recommend starting it but just in case it is not clear: DO NOT RUN AN ENGINE WITH KEROSENE IN THE CRANKCASE. In the past, people would drain a quart of oil and put in a quart of kerosene for below zero operation or to clean the engine. Now we have multi-grade and detergent oils. If the pickup screen was blocked, I would expect low, not high, oil pressure.

Re: To much oil pressure?

Sun Nov 28, 2010 4:17 pm

Besides the suggestion on removing and checking the oil pressure relief valve.

Oil coming out of the oil filter housing. In the bottom of the oil filter housing is an orifice. Remove the oil filter and see if oil drains out of the housing into the crankcase. Nother possibility is that the oil filter is completely clogged up.

Re: To much oil pressure?

Sun Nov 28, 2010 5:22 pm

Bob: I totally agree with you. I use brake cleaner since a Saab factory mechanic recommended it to me long ago - no residue and evaporates quickly. When I've suggested it in the past, it was met with silence and everyone here seems to have faith in kerosene; thus, my suggestion. When i first get a tractor, I drain pan and filter canister, leave the plugs out and spray down the breather, into the canister including the return passage until the can is used up several times letting the crud run out over time. You'll note I did suggest using the hand crank just to have total control over the situation. Craig

Re: To much oil pressure?

Sun Nov 28, 2010 7:59 pm

Easy check. Oil pressure relief valve - remove the spring. Start engine - Oil pressure will push the valve back to the nut. If oil pressure has backed valve up to the nut - it's not stuck. If it was stuck and this trick works - oil pressure will be about ZERO - very low so check for oil flow into the oil filter housing. Do not run the engine any longer than necessary, without the PRV in place, to check for oil flow.

Spring compression test is 9.5 lbs. See pages 1-55 and 1-9 of GSS 1411.

Re: To much oil pressure?

Mon Nov 29, 2010 12:55 am

all great advise! I had one that would hold 80 lbs of pressure once and nothing was stuck or wrong except it had 60 wt oil in it! one thing though, the return hole in the filter can be plugged but wouldnt raise the pressure because the inlet is in series with the rest of the oil galleys. No engine that I know has the pump plumbed paralell in the system.To my knowledge all preasurised oil systems in engines work on a bypass.

Re: To much oil pressure?

Mon Nov 29, 2010 6:17 am

Have you pulled the dipstick to check how much oil is in the crankcase? The seal on the hydraulic pump on mine went bad and allowed a substantial amount of the HY-Tran to flow into the crankcase before I realized what was going on. I mention this because of the oil coming out of the filter on yours. More experienced folks here would be able to say if an increased oil amount in the crank could indeed contribute to the high oil pressure reading.

Re: To much oil pressure?

Mon Nov 29, 2010 8:22 pm

I changed the pressure gauge and still peg that one. I took the spring out of the relief valve and started it up again and still pegged the gauge. The valve must be stuck. Any ideas on how to get it out?? If the oil pressure didn't push it back a magnet won't pull it ether. In for the night. Tomorrow night will try some more.
Ron in Mid Missouri

Re: To much oil pressure?

Mon Nov 29, 2010 8:42 pm


Couple of suggestions in the above link.

I've screwed in a bolt and pulled them out. But, It always ruins the piston/valve.

Re: To much oil pressure?

Tue Nov 30, 2010 9:51 pm

Got the valve out. Thanks Eugene for the tip. Here is how I got it out. I used a 7/16 dowel and cut a notch in the end and made a wedge to swell the end when it hit the bottom of the valve. The spring free length is real close. Haven't figured how to get the 9 1/2 lbs for the spring test length. I'll change the oil and filter and see how the pressure is. Thanks for all the help.



Ron in Mid Missouri
Last edited by Bigdog on Tue Nov 30, 2010 9:59 pm, edited 1 time in total.
Reason: re-aligned pictures

Re: To much oil pressure?

Tue Nov 30, 2010 10:07 pm

Squeeze the spring between your thumb and for finger. Or take the spring to the hardware store where they sell nails by the pound. See if the spring will compress about 1/2" at 10 lbs or less. Post office has digital scales.

Saw the wedge in the dowel trick on the site. Gonna have to try it next time.

Re: To much oil pressure?

Tue Nov 30, 2010 10:34 pm

This is another good "Tip of the week." :{_}:
Rudi - are you watching? :lol: :lol:

Re: To much oil pressure?

Wed Dec 01, 2010 1:19 pm

Wonder if that would work for a pilot bushing?

Re: To much oil pressure?

Wed Dec 01, 2010 1:54 pm

bythepond88 wrote:Wonder if that would work for a pilot bushing?

I was thinking also, but instead of wood use a brass or steel rod and a amall steel wedge that holds a hammer head to the handle.
that would probably work to pull out a transmission pilot bushing (bearing). JMO.
Bruce T.