Engine oil cooler leak question ....
- Thread starter bugdewde
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Supercharged111
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I really don't get why some of you are determined to reinvent the wheel. AC Delco replacement lines work fine and snap right in. Unlike their cheaper brethren, they actually include new o rings for the radiator side.
454cid
Sooper Pooper
Yeah, I don't want a bucket full of adapters and fittings, either. I was going to buy the cheap Sunsong lines, but I'm second guessing that, now. They're steel which I like instead of the Dorman aluminum, but the Sunsong transmission cooler lines I bought for my Saturn, didn't fit. The quick connect end was too big to fit. They go into a small version of our heater hose quick connects, not a jiffy-tite. I ordered a new AC Delco line and it went together fine.
When I bought a Dorman oil cooler line, I'm pretty sure it had a new o-ring, but that didn't make up for it being a peice of garbage that only lasted about a year.
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2001ZR2
OBS Enthusiast
In my Suburban we are on the 3rd set of lines and just fixed the leak at the radiator like the OP so that is why I might want to reinvent the wheel. Add in my 2001 Blazer and my son's 2001 you start to get the picture. These lines are notorious for being leakers in GMT 400 or 2nd Gen S10 trucks and Blazers.
I am leaning towards the AN fitting and braided hose route.
I am leaning towards the AN fitting and braided hose route.
Supercharged111
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Read for comprehension. Didn't realize it was a 454. Didn't know that about that baffle.
2001ZR2
OBS Enthusiast
Used AC Delco which made it out of the warranty then used aftermarket and those needed to be replaced again but they have the lifetime warranty
alpinecrick
I'm Awesome
evilunclegrimace
Does not always play well with others
These lines are maintenance items just like belts, cooling system hoses and tires. Some of these trucks are 30+ years old, rubber parts have a life span. I keep a couple of sets of lines on the shelf for my '90 and '92. I just changed the lines on the '98 last year and will probably have to change them sometime in the future. It is called truck maintenance for a reason.
bugdewde
I'm Awesome
I tightened it decently with a crescent wrench, but didn't crank down on it because I didn't know how tight it needed to be.
I drove it today for about 30-40 miles with no more leaking.
I will keep check on it, as I'm concerned about it loosening up by itself.
Not really going to replace anything at this point, but the AC Delco with new o-rings sound like the path for me.
I drove it today for about 30-40 miles with no more leaking.
I will keep check on it, as I'm concerned about it loosening up by itself.
Not really going to replace anything at this point, but the AC Delco with new o-rings sound like the path for me.
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If you want to go with a solution that won't leak you can start with the AN10 to 3/8 NPT fitting that has the baffle for big block fittings. You only need one of these, on the other one you can use the flat 3/8 NPT fitting.
The part description reads:
"This part threads into the port on the oil pan rail closest to the oil filter.
This fitting is the pressure supply to the oil cooler.
The return line (port farthest forward) can be a standard 3/8" NPT to 10AN adapter fitting."
https://paceperformance.com/i-51462...vy-oil-cooler-connector-3-8-npt-to-10-an.html
IF you absolutely need to go full AN... Here is the AN fitting to the radiator oil cooler:
https://www.summitracing.com/parts/vpe-16628
The fitting into the radiator is 20mm x 1.5 Male Threads.
As was stated above the OEM hard line into the radiator oil cooler doesn't leak if the o rings are installed properly. The problems are 1st the click in fittings (which are in the oil filter adapter in the small block or directly in the block/oil pan lip in the big block), and 2nd the crimp between the flexible hose and the hard-line.
My 98 K2500 7.4l has the lines that go straight into the block/oil pan lip. My truck leaks like a sieve at the oil filter adapter and at the crimps in the oiler cooler lines where the hard lines join the flexible hose. I have seen leaks from both AC Delco oil cooler lines and Dorman. It appears they are leaking at the fittings at the block/oil pan where the hard lines clip in as well. I just ordered new OEM cooler line fittings that go into the oil pan/block. I'll reuse the existing hardline sections that go into the block and the radiator. I'll cut and flair the hard lines and make my own flexible hose pieces using new fuel line and hose clamps. Don't give me a lecture about the ACDELCO hoses being fine... they aren't... they leak at the crimps shortly after install. If this doesn't work I am going full AN fittings. Haven't decided if I will try to keep the hard lines or go all hose... or some combination.
If you have the GMT400 big block and have a leaky oil filter adapter you need to watch this:
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I just ordered a 5/16 square male pipe fitters socket to remove the plugs in the oil filter adapter, and a torx bit set to remove the oil filter T30 fasteners... so I can replace the o ring and stop that leak.
If you have a small block a completely reliable and super cheap solution (if you need to keep your oil cooling capability for towing or driving hard) is to replace the fittings on the oil cooler adapter with 3/8 barbed hose to 3/8 npt fittings, run 3/8 fuel hose up to the radiator oil cooler... keep the hard line portion that ties into the radiator, cut them flair them and use hose clamps to connect them to your new soft homemade oil cooler lines. Super cheap and way more reliable than either the ACDelco or Dorman lines. If you want to spend more money you can go full AN fittings and braided line... but the cheap system won't leak either.
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