R6602 Oil Pressure Issue

[Ol-Paint]

I have a 1962 M54 cargo truck with a R6602. I bought it a little over a year ago and notice the oil pressure runs at 30-40psi until it warms up, then operates at 25-30psi on the road. The throttle sticks, so it usually idles at 1000rpm, unless I kick it down ("blip" the pedal). Idle will drop down to 400-500rpm, but oil pressure drops to 5-8psi!

Is there something else I should be looking at before trying to replace the oil pump? The tech manual seems to point towards checking filter gaskets.

Second, can the oil pan be dropped and removed without jacking the truck up and/or raising the engine? The TM's I've found on Jatonka's site seem to address removal of the crankcase on the multifuels, but not the gasser, and is almost a 3-step process (drain oil, unbolt pan, clean pan) and doesn't really say if anything else needs to be done...or I'm overlooking it.

Other points of information: A couple of weeks ago, I was driving the truck and noticed the oil pressure was low (15-20 psi). I checked the oil level and found that it was ~10-11 quarts low. Presumably, the oil pump was sucking air, which is why I'm thinking I may need to replace the pump. There is no unusual oil leakage, nor were there any puddles in the truck's normal parking space. I do not know how long the engine was low (yes, I neglected to check the level the last couple of times I drove it). I've put about 800-1000 miles on the truck since I got it and I drive it about once a month. I am running SAE 30. It has done the low pressure at 500rpm since I got it, as far as I can remember, but reading up on the TMs, it looks like the running pressure should be 50-60, not 30-40, too.

(Yes, I am kicking myself for both not starting a maintenance/operation log when I got it, as well as not checking fluid levels *every* time I start it. Both items of negligence have been rectified.)

Thanks,

Douglas

 

[porkysplace]

I have a 1962 M54 cargo truck with a R6602. I bought it a little over a year ago and notice the oil pressure runs at 30-40psi until it warms up, then operates at 25-30psi on the road. The throttle sticks, so it usually idles at 1000rpm, unless I kick it down ("blip" the pedal). Idle will drop down to 400-500rpm, but oil pressure drops to 5-8psi!

Is there something else I should be looking at before trying to replace the oil pump? The tech manual seems to point towards checking filter gaskets.

Second, can the oil pan be dropped and removed without jacking the truck up and/or raising the engine? The TM's I've found on Jatonka's site seem to address removal of the crankcase on the multifuels, but not the gasser, and is almost a 3-step process (drain oil, unbolt pan, clean pan) and doesn't really say if anything else needs to be done...or I'm overlooking it.

Other points of information: A couple of weeks ago, I was driving the truck and noticed the oil pressure was low (15-20 psi). I checked the oil level and found that it was ~10-11 quarts low. Presumably, the oil pump was sucking air, which is why I'm thinking I may need to replace the pump. There is no unusual oil leakage, nor were there any puddles in the truck's normal parking space. I do not know how long the engine was low (yes, I neglected to check the level the last couple of times I drove it). I've put about 800-1000 miles on the truck since I got it and I drive it about once a month. I am running SAE 30. It has done the low pressure at 500rpm since I got it, as far as I can remember, but reading up on the TMs, it looks like the running pressure should be 50-60, not 30-40, too.

(Yes, I am kicking myself for both not starting a maintenance/operation log when I got it, as well as not checking fluid levels *every* time I start it. Both items of negligence have been rectified.)

Thanks,

Douglas

Running it 3 gallons low on oil may have damaged the bearings creating low oil pressure . You may want to have a oil sample done to determine what kind of metal is in the oil .

 

[Ol-Paint]

Yep, already planning on that. However, I'm trying to find out what would be involved in removing the crankcase if I have to do bottom-end work on the engine.

Thanks,

Douglas

 

[BEASTMASTER]

I got the same motor and have had it for ten years. been plowing for the town for 8 yrs and the oil pressure is and has been pretty much the same as you describe. I've put over 7k miles on it between plowing and bopping around and don't give it any thought anymore, though I did put in a mechanical gauge when I was worried about it. the thing just keeps on going and going,but you got to get in the habit of checking the oil before every time you use it.and the brake fluid too. do you're circle check and put a couple gallons of 40 wght in it.good luck.

 

[Ol-Paint]

Good to know someone else's engine runs in the same oil pressure range. I'm still going to take an oil sample due to the low level incident. As noted, I'm starting a operating log--since the truck doesn't get the same amount of seat time, I'm finding that I don't have a good feel for the trends and routines like I do with my other vehicles and I think the log will help with both.

Douglas