M4050 Oil Pressure Issues?

[jethrobodean]

Google search for these gives limited results, so asking a much more focused group:

Are there any "common" issues for low oil pressure on the M4500 series tractors? Google brought up some for the B & L series is my main reason for asking.

Backstory: After years of loyal service & good maintenance, Oil light comes on at idle once things are warmed up. First on the list is to get a manual gauge on & see what I actually have, but trying to go on the offense & get a plan together in case it gives me bad news, I rely on the old girl too much. (Just did a fresh oil change, nothing out of the ordinary there)

 

[85Hokie]

Re: M4500 Oil Pressure Issues?

just curious...... what weight oil you place in it?

I know little of the M4500 - other than it is a oldie..... wonder if that had a cam plug problem?

 

[jethrobodean]

Re: M4500 Oil Pressure Issues?

I've always used 15-40

 

[85Hokie]

Re: M4500 Oil Pressure Issues?

I've always used 15-40

Nothing wrong with that!

How many hours? How long this been a problem?

 

[jethrobodean]

Re: M4500 Oil Pressure Issues?

Not 100% sure on hours, as meter quit working. Ballpark 2500-3000, based off of when it quit.

Just been an issue in last 5-10 hours. Noticed it after mowing one day last month. Haven't run much since that really warmed it up until this last weekend.

 

[100 td]

Re: M4500 Oil Pressure Issues?

Will be interesting to find out if it has dropped a screw from the end of the cam, or if it something else. I can't recall reading about any screws coming out, but I haven't been here long. Personally, if it's low enough for the oil lamp to come on at idle, it's possible some components could be lacking proper lubrication, so I wouldn't be working it until it's sorted. YMMV

 

[jethrobodean]

Re: M4500 Oil Pressure Issues?

That's why plan A is to get a gauge on it to see what I actually have for pressure.

Looking at the diagrams, it does look like there's a set screw in each end of camshaft, so it certainly seems a possibility, whether it's one that I really want to hear or not.

 

[D2Cat]

Re: M4500 Oil Pressure Issues?

The oil pressure indicator light comes on at about 7 PSI.

Don't know if that engine had cam plugs. If you can confirm it does, you can get to the front one by removing front covers. Then you can use a tapered roller bearing to push into the hole and weld there. Just have to be positive your welding ground clamp is tight and as close to the weld as possible to keep any arc from going thru bearings.

It takes a bit to get to it, but it's a 5 minute repair.

Those plugs fall out because they were aluminum and after many heat cycles they expand and contract at different rates than the steel they are seated in.

 

[jethrobodean]

Re: M4500 Oil Pressure Issues?

Not sure if this image will show up or not. #6 lists as a set screw, but #7 is a "plug pin". While possible that the set screw has come loose, if that #7 is the usual culprit for working loose, probably worth looking into first. Seems it might be accessible by knocking out the rear plug if I'm lucky.

 

[85Hokie]

Re: M4500 Oil Pressure Issues?

that would be the animal ....#7 .....if'n that is out......
Once read somewhere that the back of the case cover/freeze plug keeps that from falling out - then again, never been in there to see.

What is the name of part #11 in your chart? Does not look like a "plug" .....but it shows it going into the cam or the front of the gear.

 

[D2Cat]

Re: M4500 Oil Pressure Issues?

On the B6100 the plug was driven in the cam hole, and was an interference fit. No attachment to hold it in place. That's probably why the heating/cooling cycles causes it to come out.

 

[North Idaho Wolfman]

Re: M4500 Oil Pressure Issues?

On that engine it could have either a plug or set screw, (yes it will be the same on both ends), it depends on the motor serial #.

Pin Plug <=1572
Set screw >=1573

The serial # will be on the flat deck of the block next to the injection pump, it's a stamped # not a cast #.

 

[JerryMT]

Re: M4500 Oil Pressure Issues?

I've always used 15-40

The owners manual calls for 10W30 but that's most likely not your problem. Check the oil pressure with a gauge.At rated speed, pressure should be 43-64psig.Allowable limit is 36 psig.At 500 rpm 7.1 psig (Reference M4500 WSM)

 

[jethrobodean]

Re: M4500 Oil Pressure Issues?

On that engine it could have either a plug or set screw, (yes it will be the same on both ends), it depends on the motor serial #.

Pin Plug <=1572
Set screw >=1573

The serial # will be on the flat deck of the block next to the injection pump, it's a stamped # not a cast #.

On the M engine? Things got off on a B series for a second, so just verifying. This was an early model M4050, so if that's the case, likely the pin.

The owners manual calls for 10W30 but that's most likely not your problem. Check the oil pressure with a gauge.At rated speed, pressure should be 43-64psig.Allowable limit is 36 psig.At 500 rpm 7.1 psig (Reference M4500 WSM)

I typo'd to start with in thread, just verifying for everyone, it is actually an M4050 (But should be same engine I believe?)

Thank you for that info though.

 

[jethrobodean]

Re: M4500 Oil Pressure Issues?

that would be the animal ....#7 .....if'n that is out......
Once read somewhere that the back of the case cover/freeze plug keeps that from falling out - then again, never been in there to see.

What is the name of part #11 in your chart? Does not look like a "plug" .....but it shows it going into the cam or the front of the gear.

#11: Cir-clip, extern

 

[North Idaho Wolfman]

On the M engine? Things got off on a B series for a second, so just verifying. This was an early model M4050, so if that's the case, likely the pin.

I typo'd to start with in thread, just verifying for everyone, it is actually an M4050 (But should be same engine I believe?).

Talk about an OOPS!
There are close to the same... But a pizza is not a calzone!
M4500 1978-1985 S2600-A
M4050 1982-1985 S2600-AL

The M4050 only used the set screw, so if it's not a bad pressure switch, you're looking at a rebuild, No other option!

 

[jethrobodean]

Good news or bad, thank you for the information.

Will likely be a week or 2 before I get it in for troubleshooting. Hopefully not worst case. I kind of dread hunting down parts for this thing.

 

[BI Trencher]

Good news or bad, thank you for the information.

Will likely be a week or 2 before I get it in for troubleshooting. Hopefully not worst case. I kind of dread hunting down parts for this thing.

I know it’s been a long time, but what was the find/ solution?
I have by both a m4050 and a m4500.

 

[JohnDB]

Welcome to the forum

The op was last seen 2018 so I don't think you'll get an answer from him/her.
@Fishfarmer had an oil pressure problem on an M4500DT a while back, I think he traced it to a partially blocked engine oil pump sump strainer (surplus gasket gunk?) but he'd be better to explain.

 

[Fishfarmer]

Google search for these gives limited results, so asking a much more focused group:

Are there any "common" issues for low oil pressure on the M4500 series tractors? Google brought up some for the B & L series is my main reason for asking.

Backstory: After years of loyal service & good maintenance, Oil light comes on at idle once things are warmed up. First on the list is to get a manual gauge on & see what I actually have, but trying to go on the offense & get a plan together in case it gives me bad news, I rely on the old girl too much. (Just did a fresh oil change, nothing out of the ordinary there)

I had the same issue with my M4500DT which I thought (hopefully) was the cam plug. The oil light was flickering on at slow idle. The manual says that was normal but I beg to differ. After more use when it got hot the oil light came on at revs, so I immediately stopped to save blowing it up. I connected an oil pressure guage with two foot of hose in place of the sensor. I started it and it went to about 15-20 lbs cold. This wasnt good. As it got warm again it dropped to below 10lbs so I stopped and decided to strip the engine down thanks to good advice from JohnDB.

I pulled the cam out and the plug hadn't come undone. Wolfman gave me the serial numbers but I forget now whether I have a pin plug or set screw. I can look up the serial number if it helps you. My engine is S2600-A. But the cam plug wasn't the problem with my engine.

JohnDB suggested the oil pickup could be clogged. After years of engines running and straining the gunk over time they block, no matter what oil you use IMO. So I bit the bullet and took off the whole front assembly. Bear in mind I also had an engine knock which I couldn't diagnose. This gave me more reason to strip it down. Its a PITA that you cant drop the sump on these to check, unlike a car engine.

Well JohnDB was correct, the oil pick up strainer was 1/2 to 2/3rds blocked. I also replaced the oil pump which may not have been necessary, the old one seemed alright but for the price why not. I also backflush all the galleries with kerosene.

Bottom line is my oil pressure is 60lbs cold now and when it heats up I am running at least 40lbs at revs and it drops to 20lbs on slow idle. I still leave this pressure gauge on. I have fixed it to the front so you can see what the pressure is all the time. I hope this may be of some help to you.