DT361 engine oil pump

[IA1456]

Is there anyone out there that has any knowledge on the oil pumps on a 361. I've got a 1206 that I overhauled and spun a rod bearing at about an 1 hour of use. The rod bearings look like they where starved for oil. How can I tell if my oil pump failed ? I'm afraid to start it that the damage will happen before I can see what my oil pressure is? Any suggestions

 

[caterpillar guy]

With the oil pump off set the intake in a pan of oil and turn the gear it should move oil through the pump. There is a pressure regulating valve that could have gone bad also in that system. If you have a plug in the crank or in a block oil galley that would cause your problem. If you could pull the timing cover and spin the cam shaft without the valve train it would pump oil throughout the engine if the complete lubrication system is assembled on the block. The oil pump is driven off the camshaft. There could also be an air leak in one of the joints in the oil tubes allowing air in and the pump to not prime. If you have the crank out blow air through each passage to tell if there is a plug and also to know they are open. If you have a separate oil pump of some sort you could also fasten that to a plug hole in the block and deliver oil to the block to see if oil flows to each place by watching as you pump oil through the engine while it has the pan off. No need to turn the engine this way either. This method would probably be the easiest. IF there was oil in the filters when you took it apart it probably was not your pump.

 

[IA1456]

I agree on the not being the pump but I can't ignore the fact it looks like there wasn't enough pressure to oil the bearings

 

[caterpillar guy]

Well since I'm not there I can't see it. There is a pressure regulator valve in the casting by the pump and oil filters that controls the pressure from 98 55 psi I think it is. If that went south you could I suppose lose oil pressure enough to cause damage. Though I would suspect a plugged galley first. And to find that I would pull the bad rod off and try pushing oil out through the crank with a pump hooked to one of the threaded holes in the oil galley then see if oil comes out of the rod . If not you have found your problem. If the crank was warped and they siad they could grind it straight that will also cause it to go out. I had a guy sell me that line a hundred years ago and the bearing went out like yours did and with in 20 miles on a car.

 

[Janicholson]

Put a pump oil can output through a small hose into the oil gallery where the pressure sending unit is screwed in. With the oil pan off, you should be able to see well enough that if you pump pressure into the gallery (might take a few refills) the leak will show up. It couild be a gallery plug that was removed for the rebuild. Was assembly lube used when putting it together? I make sure I run pre start oil into the engine with a little pump, or oil can. As soon as the trigger gets hard to pump, it will be primed. Jim

 

[used red MN]

I am really sorry to hear you are having so much trouble with this project. What do you know about this tractor before you tore it down for the overhaul? I checked back on you older posts and I see after assembly the camshaft key sheared and half or so of the push rods were bent. You determined that was possibly from the cam retainer plate having incorrect dimensions. After the push rods bent did you pull the head to check for piston damage? Damaged pistons can gall to the cylinder and cause rod bearing failure. Others have gave you some ideas on checking the oiling system. Pumping oil into the system with a pump to see if there is a major leak off somewhere is a good idea. Building a pump out of an old used automotive oil pump that can be turned with a drill is not to difficult. Just make sure it has been disassembled and cleaned. As far as oil pressure on start up, most engines after a couple of 10 second cranks should develop oil pressure at cranking speed.

 

[IA1456]

The tractor you are referring too with the cam shaft issues was a different tractor couple of projects back thanks I do appreciate your detailed input

 

[MontanaRancher]

For what it is worth I have installed mechanical oil pressure gauges on my old tractors, just don't trust the lights.

APF