model AR oil pump removal

[billCollins]

So i have a 1942 model AR tractor with no oil pressure. I have resigned myself to the fact that I'll need to check everything (clean and inspect the oil pump, strainer, new filter and oil, check the relief valve, etc). My problem is how to best remove the oil pump outlet pipe as I'm removing the pump....can I get a wrench in the small space that is between the pump/strainer and the bottom of the crankcase and unscrew the oil outlet tube or will i need to reach into a drained crankcase and unscrew the fitting?

 

[Loosehandle]

Before I'd do all that, I would check the oil pump drive coupler and replace the filter especially if its been in there a long time.

 

[billCollins]

to check the coupler i'd need to pull the pump/strainer assembly, so I still need some advice on the best way to do this....

 

[Mark-Ia]

To check the coupler, remove the crankcase cover, follow the oil pump shaft up to the top of the shaft. Your coupler should be there. If its broken, all you need to remove is the round plate below the pump. not the complete assembly.

 

[billCollins]

i see, so could i also spray some diesel fuel or air up inside there to clean the strainer while the gear pump shaft is removed (ie, is there enough room to insert a wand of some sort...)

 

[Mike(NEOhio)]

To check the coupler, remove the crankcase cover, follow the oil pump shaft up to the top of the shaft. Your coupler should be there. If its broken, all you need to remove is the round plate below the pump. not the complete assembly.

Whil you're in there reach down and feel around the pump screen for sludge. Roll up your sleeve or drain it first.

 

[PJH]

To check the coupler, remove the crankcase cover, follow the oil pump shaft up to the top of the shaft. Your coupler should be there. If its broken, all you need to remove is the round plate below the pump. not the complete assembly.

As Mark said. Also, when removing the round plate, temporarily replace the plate bolts with longer bolts to allow the pump drive to drop down the needed amount and still keep the gears in place.

 

[billCollins]

So today I changed the oil and filter, opened up the crankcase. The square drive for the pump looked good but the oil line that comes out of the pump and to the filter assembly wasn't connected at the pump/strainer assembly. Tightened up that tubing fitting and buttoned up the crankcase. The oil pressure needle barely comes off the low peg so I guess my next step is to tighten down on the relief valve. Any advice on how many turns I should try? Are replacement relief valve springs available?

 

[billCollins]

I was able to finally raise my oil pressure this weekend by adjusting the the "pressure relief valve" which is actually a pressure regulating valve since it's constantly letting excess oil out to control pressure.
I tightened down on the screw which is on top of the spring and didn't see pressure raise until abut 2 full turns on the screw, then was confined to about a 1/8 of a turn to get a control band between Low and High pressure.
I know that increased oil pressure will lead to higher oil consumption so I'll keep an eye on this. If this becomes a problem I plan to use High mileage oil from Valvoline and go from 30 weight to a 40 weight oil.

 

[Pappy]

I was able to finally raise my oil pressure this weekend by adjusting the the "pressure relief valve" which is actually a pressure regulating valve since it's constantly letting excess oil out to control pressure.
I tightened down on the screw which is on top of the spring and didn't see pressure raise until abut 2 full turns on the screw, then was confined to about a 1/8 of a turn to get a control band between Low and High pressure.
I know that increased oil pressure will lead to higher oil consumption so I'll keep an eye on this. If this becomes a problem I plan to use High mileage oil from Valvoline and go from 30 weight to a 40 weight oil.

Why would you think the higher oil pressure would cause excessive oil consumption? Could someone explain this, please.

 

[Mike(NEOhio)]

I was able to finally raise my oil pressure this weekend by adjusting the the "pressure relief valve" which is actually a pressure regulating valve since it's constantly letting excess oil out to control pressure.
I tightened down on the screw which is on top of the spring and didn't see pressure raise until abut 2 full turns on the screw, then was confined to about a 1/8 of a turn to get a control band between Low and High pressure.
I know that increased oil pressure will lead to higher oil consumption so I'll keep an eye on this. If this becomes a problem I plan to use High mileage oil from Valvoline and go from 30 weight to a 40 weight oil.

I had to do the same thing on my A after I switched to T4 15W-40 from the Valvoline 30 I always used. I was worried some because it's really in good shape mechanically. I have the same question as Pappy.

 

[billCollins]

Why would you think the higher oil pressure would cause excessive oil consumption? Could someone explain this, please.

It's what John Deere advises...higher oil pressure leads to higher oil consumption. I think that's due to more oil being supplied to the rocker arm/valves/head assembly and the oil then getting sucked into the engine.