oil filter 77 300d

[james f. coon]

I'm new to diesel's and the mechanics of the 300d but learning quick. Drained the oil a few days ago. Contaminated with charcoal lighter fluid. (That's a whole new story). Took oil filter out today. Noticed there was no oil in the oil canister and hardly any oil in the cooler. Is that the norm when the oil is drained? Also because when I fire up cold start the oil pressure is at 45 lbs but after it runs a while the pressure drops to 15 lbs. Someone suggested the spring in the oil filter canister may be bad causing the oil pressure to drop. I don't even see a spring in there. Removed the canister and no spring in there, nor in the innards of the section that bolts to the block. I took the oil pressure line off and there wasn't any spring there either. No help nor phots in Haynes. Anyone know where abouts that spring should be?

Any help would be appriciated, Jim

[Lycoming-8]

If this is a W115 bodied 300D then yes there is likely supposed to be a spring in there with the filter. It has been quite a while since I changed the oil on the old '68, which I believe was at the bottom of the can and the 2 filter sections sat stacked on top of it. If this is a W1123 then I doubt that is any different from the other W123 diesel filters and won't have a spring.

Also if your pressure is down to 15 or 20 psi at idle after warm that is in the ball park. However if the lower pressures are while running, there are some problems. Post some answers back and we can probably straighten out what is going on.

[DieselBone]

being a 77 its a w123 N/A

[james f. coon]

Originally Posted by Lycoming-8

If this is a W115 bodied 300D then yes there is likely supposed to be a spring in there with the filter. It has been quite a while since I changed the oil on the old '68, which I believe was at the bottom of the can and the 2 filter sections sat stacked on top of it. If this is a W1123 then I doubt that is any different from the other W123 diesel filters and won't have a spring.

Also if your pressure is down to 15 or 20 psi at idle after warm that is in the ball park. However if the lower pressures are while running, there are some problems. Post some answers back and we can probably straighten out what is going on.

77 300D is a 123 series 617.912.
Thanks, jim