Oil Lines

[DTrain]

I am in the middle of an engine swap/upgrade in my '99 K3500 pickup. I have pulled the old tired 350 out of the truck and have a rebuilt, fully ready 454 sitting on the stand ready to go back in.

Over time, I have really learned to hate the oil cooler lines that came on the truck to begin with. Over the 354,000 life of the truck, it has seen a few sets of cooler lines. The last set I did I had some custom ones made up the way I wanted. They lasted much, much longer then the weird factory GM lines, but as with every other replacement they eventually had a leak of some sort, even if just minor residual evidence around the fittings.

The 350 I just pulled was the original motor and was 100% stock. It had an aluminum block bolted to the engine that the oil lines threaded into as well as the oil filter. This unit here seemed to be a continual maintenance issue and was always wet with oil of some degree.

The 454 is set up to have the oil filter threaded directly to the engine block. Next to the oil filter location there are two holes, that are currently plugged, where I have found in my research is a different way of threading in oil lines if the vehicle is set up to do so.

I am wondering how important it is to have these oil lined hooked up with the new motor? If I can get away from these, I would be thrilled, but understand if it is a necessary evil. Look forward to everyones experience and opinions on this one.

Thanks,
D

 

[PlayingWithTBI]

Are you planning on any heavy towing?

 

[DTrain]

I am no hot shot trucker, but I am in the carpentry business and I do pull and enclosed tool trailer pretty regularly. I pull machinery a few times a year at the most. That said, it is a one ton truck and needs to be capable and able to do what a one ton truck was made to do.

 

[454cid]

I plugged the oil cooler ports on my truck, but I don't tow much, or carry heavy loads.

If you do decided to go with hydraulic lines you'll need to get the proper adapters. You can't just screw lines directly into the block. You need the fitting with the restrictor on it. My understanding is that It creates the pressure differential that creates the flow.

 

[grampadirt]

I replaced the lines on mine a few years ago after the oem ones got to leaking.I just figured it was part of the Burb and needed to be there.I thought it was a PITA but an afternoon of work and beer drinking and it was done.Oh yeah..throw in a few four letter words as well,LOL.

 

[DTrain]

I went ahead and ordered factory AC Delco lines and fittings. I don’t think I should have to worry about them for a while. I do know the last set I did on the 350 before I did the custom lines were Dorman, which over the last few years I’ve learned my lesson on different products of theirs being total junk. I think going OEM and not having the aluminum unit bolted to the block I oughta be in good shape.

 

[tdc917]

To anyone else whose old lines are leaking (which is all of us if they’ve never been replaced), you can convert them to pre-made braided lines with AN fittings for the same cost of Delco replacements and never have to worry about them again. I wouldn’t recommend even wasting your time with the Dorman replacements, they’ll also be leaking in short order. I have actually heard good things about the Sunsong ones on RockAuto, but decided to just go braided instead of doing the job over once a year. Also, it should go without saying but do yourself a favor and do not run expensive synthetic oil if your lines are leaking. An $8 quart of oil once a week adds up, don’t ask me how I know.

You could also just delete them and be fine. Run synthetic oil if it makes you feel better, but even the cheapest conventional oil will have no issues at 250f for 3-5k miles. The main advantage to the cooler lines is actually the heating effect on cold days IMO.

 

[TheAutumnWind]

To anyone else whose old lines are leaking (which is all of us if they’ve never been replaced), you can convert them to pre-made braided lines with AN fittings for the same cost of Delco replacements and never have to worry about them again. I wouldn’t recommend even wasting your time with the Dorman replacements, they’ll also be leaking in short order. I have actually heard good things about the Sunsong ones on RockAuto, but decided to just go braided instead of doing the job over once a year. Also, it should go without saying but do yourself a favor and do not run expensive synthetic oil if your lines are leaking. An $8 quart of oil once a week adds up, don’t ask me how I know.

You could also just delete them and be fine. Run synthetic oil if it makes you feel better, but even the cheapest conventional oil will have no issues at 250f for 3-5k miles. The main advantage to the cooler lines is actually the heating effect on cold days IMO.

Where do we get the premade braided AN fitting line setup? I need a how to!

 

[PlayingWithTBI]

Almost looks like there's 2 similar threads going on here. Maybe some of this will help?

https://www.gmt400.com/threads/6an-lines-fittings-for-trans-coolers.44354/#post-1039618

 

[tdc917]

Where do we get the premade braided AN fitting line setup? I need a how to!

Not sure if I’m supposed to plug websites or whatever here, but google AN plumbing and go to the first website.

You need a 40 inch -6an hose straight on one end to 90 degree swivel on the other end for the lower. And 50 inch -6an hose straight on one end to either 45 or 90 degree swivel on the other end for the upper. That will be about $100 shipped. Well worth it IMO to not have to make them yourself and risk leaking.

Then go on eBay and get two -6an to 3/8npt fittings, those are for the oil filter housing side. And get two 20mm x 1.5 to -6an fittings for the radiator side. And you’ll need thread sealant, I like the permatex paste with the brush. And get an oil filter housing gasket. I get the OEM GM ones off eBay, they’re like $7. All of the above will be about $25.

Remove your old cooler lines, make sure you get the o rings out of the radiator if they don’t come out with the hose. It’s much easier to take the oil filter housing all the way off, it’s only two bolts. Clean the housing up, thread in your fittings with thread sealant, replace gasket and put the housing back on. Then mate up your new lines to the radiator fitting adapters, I use thread sealant on every connection. Start on the radiator side connection with the lower and run it down to the ground temporarily, then do the same with the upper. Then go underneath, route cleanly through the factory bracket and attach to the housing side fittings. Torque everything to good and tight, don’t strip anything. Degreasing is recommended but optional. Monitor your oil level for a week, then get under again and check for leaks after you get some miles on it. Tighten if necessary and enjoy your new lifetime leak-free lines.