MF-205 Industrial Oil Pressure Drops When Warm/Hot

   / MF-205 Industrial Oil Pressure Drops When Warm/Hot #1  

jfharper

Member
Joined
May 4, 2010
Messages
31
I'm running 20-50w oil in the Perkins AD3.152, with a spin on oil filter. When I first start, the oil pressure gauge reads about 50 when environment temp is above 70 degrees F, or about 55 when enviroment temp is cooler, like 50-60 degrees F. As the tractor warms up, the oil pressure drops gradually until it stays at 0-5 at idle, or 5-10 at higher rpm. I called the shop and they said it most likely is the oil pump. Can someone please give me a second (or third) opinion on this?

I found an oil pump for about 60 bucks online plus shipping...and read someones post on removing the oil pan...I think the shop told me once you remove the pan, the pump is right there. I think in the post I read I have to block the front pivot axle with wedges so it doesn't swing in the way.

After removing the pan, can I change out the pump pretty easily or are there other things to remove first?

Could it be something other than the pump, like the relief valve? I'm kind of new to this, however, I have already slipt the tractor (twice) and replaced the clutches. Funny story about that, is after I replaced the clutches and put the tractor back together and started it up, it wouldn't move, so I thought I did something wrong and split it again, and checked all my work, and everything looked fine...then I called the shop and someone mentioned you may need to prime the pump which runs the clutches...funny I didn't see that mentioned in the service manual, so I put the tractor back together again, ran it and kept pushing the pedal (instant reverse) back and forth then finally the pump got primed and it started to move. Learn by doing I guess.

I have a MF Service Manual and it seems very good with expaining stuff...I just thought I would get some quick online guidence if anyone has any.

Thanks.
 
   / MF-205 Industrial Oil Pressure Drops When Warm/Hot #2  
While our 265 MF does not do this (only 1250 hours) I would think bearings first. I would look at single grade (not sure what they have out there but 40 would be what I would try to see if that helped the numbers.

I just have never seen a "weak" oil pump but I am sure they happen.

Let us know what you fine.
 
   / MF-205 Industrial Oil Pressure Drops When Warm/Hot
  • Thread Starter
#3  
Gale,
Thanks for your fast reply.

I'm sorry, I am lost on your post. Were you referring to the bearings in the oil pump or crankshaft bearings?
 
   / MF-205 Industrial Oil Pressure Drops When Warm/Hot #4  
Sorry, on the crank (mains and rods).

On second thought you could add something like STP, Lucas, etc that takes forever to pour out of a can on a hot day.

Others can help you with this because I have not used any since the old 53 Chevy PU that burned a quart of oil every 40 miles. :)

What you are wanting to do is gather some info before you start swapping parts willy nilly.

Is this a new development or one over time?
 
   / MF-205 Industrial Oil Pressure Drops When Warm/Hot
  • Thread Starter
#5  
This has been going on over time. The other thing, I failed to mention is the engine probably burns 1 1/2 - 2 quarts after 4-6 hours of running. It hasn't been that bad before this year, but I have been running the tractor longer and harder as of late. So I'm probably looking at doing an overhaul...which would be kind of fun to do. I always like taking on a new project and this engine doesn't seem all that difficult to get in and fix. I'd appreciate the education of it.
 
   / MF-205 Industrial Oil Pressure Drops When Warm/Hot #6  
If you can not find an additive to get the pressure up to some min PSI I would do it sooner than later while your crank may not be damaged.

Running worn out equipment I know about. They can drink oil for a long time but they can not run a long time with oil PSI below a certain factory spec.

However low pressure is not always as bad as it sounds if the volume of flow has increased due to lower pressure.

As a note for $60 I would replace the oil pump at the over haul. Since you are wanting to play inside of the engine go ahead and drop the pan and do it now to see if it helps since you are going to do it anyway.

While the pan is off feel of the end play/slack in the rod caps. Years ago dad would buy a kit that "assume" X amount of crank wear so the new bearings made up the difference.
 
   / MF-205 Industrial Oil Pressure Drops When Warm/Hot
  • Thread Starter
#7  
Good to know...thanks.
 
   / MF-205 Industrial Oil Pressure Drops When Warm/Hot #8  
I hope this is the continental gasser you are running the 20-50 in.. as I don't know of too many C rated 20w50 oils.

Unfortunately what you describe is usually a combination of worn main and rod bearings.. and even a worn oil pump.. many people go up an oil grade.. however 20w50 for a gasser is up there as your cold pressure is high. I do know of some people with engines worn slap out that absolutely have to use them that run straight 50w or straight 60w oil just to keep hot oil pressure on a ratling old engine.

if you have a relief valve.. check it to make sure it is up to spec.. though with cold temps int he 50's.. it likely is fine..

soundguy
 
   / MF-205 Industrial Oil Pressure Drops When Warm/Hot
  • Thread Starter
#9  
No, it is the perkins diesel. A dealer parts guy told me to use 20-50w a long time ago, and that is what I have been using...the book says 30w dg (heavy duty, high detergent), but the pressure did the same thing on running 30w.

It does have a relief valve...and I'll check that. Thanks for the reply. I don't understand how worn main and rod bearings could affect oil pressure like this...I guess I'll google that and see if I can understand it...thanks.

I was also wondering about the valves and guides or seats. My neighbor was saying if it drinks oil the valves and stuff in the head could be shot too. I don't understand that yet either, but do you think the valves, guides, or seats have anything to do with the oil drinking? I thought oil drink was caused by worn piston ring blowby.
 
   / MF-205 Industrial Oil Pressure Drops When Warm/Hot #10  
Worn valve guides can cause oil usage. PSI is not directly effected however. You have a weak pump or plumbing leakage (worn bearings) or both.

Poke 8 holes into your water hose and see what happens to the pressure at the end. :)
 
 
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