Chev 454 oil cooler

I know there are a lot of people on here that would know this answer, I couldn't find a solid answer on google.

1989 Chevy K3500 454, engine oil cooler lines are leaking. They come out of the oil pan rail (block) right in front of the oil filter. Can I just plugs these old ports? I couldn't find an oil flow schmatic on the web. If not I can bend up a short bypass loop.

The reason I am not replacing them $130. This is a old plow truck in Michigan. Just getting it along til the salt attacks something else.

To keep it tractor related, I use this truck to occasionally move my tractor mounted tree spade around.

Thanks,
Rick

This is NOT specific to your engine, but typically if the ports are simply plugged an internal oil cooler bypass valve will be held open by the flow of oil.

There MAY be a smaller plug inside one of the ports that can be removed to prevent this and allow the free flow of oil.

Another thing GM sometimes did was to make one of the cooler fittings with a sort of "probe" attached that plugged the internal passage when an external cooler was installed. Removing the special fitting opens up the internal passage. You might try removing the fittings and see if one is made like that.

BTW, you can replace the cooler lines WAY cheaper by using hydraulic hose with flareless connectors at each end to match the metal part of your cooling lines.

The implement dealership where my BIL works gets a lot of business from the local Chevy dealer who does just that.

ANY shop with a hydraulic hose machine and a good stack of fittings should be able to make you up a set.

The link below will show the type of fitting I am talking about:
Flareless

I have a brand new set I bought to add to a '90 K3500. Never got to it before I sold the truck.

Was just looking at them the other day as I was going through some stuff. I'll sell them for a lot less than $130.

Send me an email if your interested.

The GM oil cooler lines have a tendency to leak. The last set that I ordered, GM had even discontinued them for that application. The aftermarket had them for a pretty good price. A different application I'm sure, but they were a lot less than $130.

I have a 350 in a 3500 daully pick up and all I did to mine cause the lines leaked bad I went to a junk yard a got a stock oil filter adapter and took off that stuipd thing that the oil filter hooks to and done away with the oil cooler part i dont haul heavy or far to need it and dont have the worries about the oil leaking and hurting the motor and the mess

My 97 has started to leak but the hoses are a lot less at O'Reilly's.

Bob,

I removed the two fittings, one does have a tapered plastic probe on it, if that is what you would call it. It sticks above the fitting about 1 inch or so.
The probe is open on all four sides, reminds me more of a metering orifice. I plugged the ports and fired up the engine, oil pressure was fine, maybe a little higher 5-10 lbs.

I have flareless fittings to make a short return loop or even plumb in a new cooler. But, I am trying to understand if that probe changes the flow. I guess it shouldn't since it is open anyways.

I did find this info, after digging pretty deep on a 7.4 Gen V motor.

[i:6cd838aac9]After leaving the pump, the pressurized oil flows through a full-flow oil filter. On engines with an engine oil cooler, the oil also flows through the cooler before returning to the block. A bypass valve allows oil to bypass
the filter and oil cooler should they become restricted. Some of the oil, after leaving the oil cooler and/or filter, is routed to the No. 5 crankshaft main bearing. The remainder of the oil is routed to the main oil gallery,[/i:6cd838aac9]

This still doesn't say if all the oil goes through the filter and then the cooler, but it sounds like it. I think I'll just make up the small line between the 2 ports and call it good.

Do you agree?

Jeff, thanks for the offer on the lines, I will keep that in mind if this fix doesnt work.

Rick

Rick, that fitting is EXACTLY what I was referring to and I am 99.9% certain the plastic "probe" plugs a port down at the bottom of the port when installed forcing the oil through the cooler and with it removed and the 2 cooler fitting holes are plugged oil will safely flow INTERNALLY so no external bypass line is needed.

Of course that leaves a small uncertainty the YOU assume the risk of!!!