WD45 - Very High Oil Pressure
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=203707
Printed Date: 18 Apr 2025 at 7:50pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: WD45 - Very High Oil Pressure
Posted By: StanGreen
Subject: WD45 - Very High Oil Pressure
Date Posted: 17 Oct 2024 at 8:52pm
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On my WD45 today, I notices the oil pressure gauge is pegged to the high side at idle. I had the motor rebuilt last year. The oil does not look like it is over filled. Is it OK to have this high of oil pressure? If not, what would be my first step to address this issue? |
Replies:
Posted By: steve(ill)
Date Posted: 17 Oct 2024 at 9:00pm
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get a good gauge and read the REAL pressure.. ------------- Like them all, but love the "B"s. |
Posted By: Eric B
Date Posted: 17 Oct 2024 at 9:12pm
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I have the same issue with one of my 201 engines. I put a real gauge on there and it reads 90 lbs. I had to believe it reading a real gauge. Once the engine warms up the original gauge points straight up in the normal range (still about 45 lbs on the real gauge). I have now changed oil putting much thinner oil in it. The gauge still goes over to the far end on cold start up but takes shorter time to come back to the middle. A mystery to me. ------------- Currently- WD,WC,3WF's,2 D14's B. Previously- I 600,TL745,200,FL9,FR12,H3,816 LBH. Earth has no sorrow that Heaven cannot heal! |
Posted By: jvin248
Date Posted: 17 Oct 2024 at 9:26pm
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. Gauges fail. Verify and if bad then replace it. .
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Posted By: steve(ill)
Date Posted: 17 Oct 2024 at 9:49pm
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does the "Rebuilt" motor use the old BYPASS jar lip thread filter.... or the PH8 type automotive full flow filter ?? ------------- Like them all, but love the "B"s. |
Posted By: DrAllis
Date Posted: 17 Oct 2024 at 10:56pm
| Remove the filter base tube and clean it out by ramming a piece of wire down thru it and blowing air into it. |
Posted By: StanGreen
Date Posted: 18 Oct 2024 at 4:57pm
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I just so happened to have a brand new oil pressure gauge, so I install the new one. It did not change anything. My pressure is still on the very high side. The temp here is in the mid-60s so I would not expect the oil to be thick. I also ran the tractor for a few minutes before changing the gauge. Any more thoughts?
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Posted By: DrAllis
Date Posted: 18 Oct 2024 at 5:41pm
| Well, you haven't said how much pressure you have !!! 80 psi?? 100 psi??? or 30 psi ??? |
Posted By: steve(ill)
Date Posted: 18 Oct 2024 at 6:41pm
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Mid range on the gauge is about 15 psi... The "HIGH" side might be 25 psi (???) .... not much to worry about, but good idea to figure out WHY ? ------------- Like them all, but love the "B"s. |
Posted By: Alberta Phil
Date Posted: 18 Oct 2024 at 8:20pm
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I have a WD with a WD45 engine and had the same problem on initial start-up. It was the pressure relief valve that was stuck closed. It is behind the large hex plug on the lower right side of the block, by the dipstick. The hex plug has a spring that holds the flat faced piston over the oil hole in the gallery. I had to tap mine a bit and finally pull it out with a strong magnet so I could clean it up and also the mating surface where it seals. After that the indicated pressure runs close to the L in NORMAL on the gauge. |
Posted By: StanGreen
Date Posted: 18 Oct 2024 at 10:05pm
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The standard AC gauge does not show PSI, only "Normal". The specs say the gauge max is 30 PSI, so I assume that is what I am seeing. |
Posted By: StanGreen
Date Posted: 18 Oct 2024 at 10:08pm
Thanks, I will check that out.
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Alberta Phil wrote:Posted By: Phil48ACWC
Date Posted: 21 Oct 2024 at 6:55am
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I run a 0-60 PSI gage on my freshly rebuilt WC with 10W-40 Full Synthetic oil and hold 32 PSI fully warmed up with a 180 degree thermostat while mowing in the Summer. It will hold closer to 35 PSI in Winter while plowing snow. Install a real pressure gage and don't worry about it. Below is similar to the gage I'm using: https://www.ebay.com/itm/165569103067?_skw=pressure+gage&itmmeta=01JAQENHD31NY08KGA8XKCAAKT&hash=item268cb004db:g:0VQAAOSwj5ViyJQm&itmprp=enc%3AAQAJAAAA0HoV3kP08IDx%2BKZ9MfhVJKnSy25sVXBvBPDuA89ZNyFIyrHYtDo7eK0RH3ZAjaJaDiGYVO%2F0hhUgoB7o7oUyEVR9qSpW4CkbCMvtik195qzAMzjn6kJE9Pj4EldnWx7wD0W2Vse94mBgY968xFShXplSDEo1xJW8qRgXf5zVJe1bS4Ez3UG05DKd4S4heuKUJ8F2icJK4srtXFP7E43Y8xnpaJJJws1dRgTpRTNbCaBGdzdbjRHBFcnAx7Fryl4dp842iLGNCr8LWQea6Xs6EzQ%3D%7Ctkp%3ABk9SR-aW1u7VZA" rel="nofollow - https://www.ebay.com/itm/165569103067?_skw=pressure+gage&itmmeta=01JAQENHD31NY08KGA8XKCAAKT&hash=item268cb004db:g:0VQAAOSwj5ViyJQm&itmprp=enc%3AAQAJAAAA0HoV3kP08IDx%2BKZ9MfhVJKnSy25sVXBvBPDuA89ZNyFIyrHYtDo7eK0RH3ZAjaJaDiGYVO%2F0hhUgoB7o7oUyEVR9qSpW4CkbCMvtik195qzAMzjn6kJE9Pj4EldnWx7wD0W2Vse94mBgY968xFShXplSDEo1xJW8qRgXf5zVJe1bS4Ez3UG05DKd4S4heuKUJ8F2icJK4srtXFP7E43Y8xnpaJJJws1dRgTpRTNbCaBGdzdbjRHBFcnAx7Fryl4dp842iLGNCr8LWQea6Xs6EzQ%3D%7Ctkp%3ABk9SR-aW1u7VZA
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Posted By: Eric B
Date Posted: 23 Nov 2024 at 8:41pm
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Stan Green: I'm wondering if you got your oil pressure issue resolved? As you may have read my input further back in this thread about my start up pressure being 90 psi and still quite high at operating temperature. Yesterday I removed the access cap to the pressure relief valve to discover that the plunger was seriously stuck in the fully closed position. The engine had been inactive over a couple of decades and with enough sludge etc hardening in there the relief plunger was non-functioning. It is no easy task to get it out being as stuck as it was, I will spare the details for another time. Once I had it all cleaned up and put back together the oil pressure was perfect like any 201 cu. in. should be. My thanks to Alberta Phil for sharing that this had been an issue for him in the past as well. ------------- Currently- WD,WC,3WF's,2 D14's B. Previously- I 600,TL745,200,FL9,FR12,H3,816 LBH. Earth has no sorrow that Heaven cannot heal! |
Posted By: StanGreen
Date Posted: 25 Nov 2024 at 9:01am
Thanks Eric. No, I have not tried cleaning out the relief valve yet. The old girl is in storage for the winter. This is on my list of projects for the spring.
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Posted By: StanGreen
Date Posted: 11 Apr 2025 at 3:57pm
Well spring is here and I did clean out the relief value. It was hard to get out and an almost impossible task to get back in! The spring tension makes it so you cannot just screw it back in. I ended using a small wood block to hold the cap while I screwed it in.
And after all that, my oil pressure is still just higher then "Normal" on the AC gauge.  But I would rather have pressure that is too high than too low. |
Posted By: Eric B
Date Posted: 12 Apr 2025 at 12:57am
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Hi Stan: The way you are describing the tension of the spring on your tractor has me convinced that someone in the past has replaced the original one for a stiffer spring. The original ones are not that hard to put back in by simply pushing the cap in gently with your fingers. If you can find an original strength spring and install it, I'm sure you'll find the pressure will normalize. I bought this tractor long ago, sat for lots of years to find out that it had no oil pressure at all once I got it running. Upon removing the oil pan I found out all the teeth on the camshaft for driving the oil pump were stripped off. I installed a camshaft from a donor engine to find out that I had this very very high oil pressure. My thought was that perhaps at cold weather starts (in Canada), with maybe 30W oil, the teeth on the camshaft couldn't handle the resistance and consequently sheared off. Would I risk this again? No Chance... this is why I was so relieved to find the relief valve being the trouble maker. If I were you I would put in a weaker spring. ------------- Currently- WD,WC,3WF's,2 D14's B. Previously- I 600,TL745,200,FL9,FR12,H3,816 LBH. Earth has no sorrow that Heaven cannot heal! |
Posted By: StanGreen
Date Posted: 12 Apr 2025 at 10:05am
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Thanks for the info. Knowing the history of the tractor, I doubt the spring is not original. Now I am thinking maybe the plunger is not going in all the way. When I get it somewhere I can park it for a while, I'll take a closer look. That will not be until summer. |
Posted By: Eric B
Date Posted: 12 Apr 2025 at 3:54pm
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If the plunger is not going in all the way you would have too much relief and the oil pressure would be very low. If the spring is original, it's possible that washers/spacers have been placed inside the plunger to give the spring more push and consequently higher pressure. It is a good thing to pull the plunger out and clean it up so that it slides smoothly. To test things after the 'clean up' you could put the cap back in place and do a quick start up without the spring in there just to see the reading on the gauge. Thanks for letting us know your progress as summer comes. ------------- Currently- WD,WC,3WF's,2 D14's B. Previously- I 600,TL745,200,FL9,FR12,H3,816 LBH. Earth has no sorrow that Heaven cannot heal! |
Posted By: StanGreen
Date Posted: 14 Apr 2025 at 7:42am
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Now that you mention it, there were washers in the plunger. I just put them back in thinking they belonged there. I'll try taking them out to see what happens. This will also likely make the cap easier to reinstall!
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