1996 - 2000 GM OBS 4WD K Truck Vortec V8 5.0L / 5.7L Oil Cooler Line Leak Repair (Chevy & GMC)

In this video we tackle an engine oil leak on the engine oil cooler lines on GM K truck (4WD) models (e.g., K1500, K2500, K3500) with the Vortec V8 engine (either 5.0L or 5.7L). Whether from Cadillac, Chevrolet, or GMC.
The vehicle illustrated is a 1998 Chevrolet Cheyenne K2500 with the 5.7L vortec engine, but the procedure, parts, and technique shown is applicable to any 1996 thru 2000 old body style (OBS) GM truck GMT400 type such as the Chevrolet Silverado, GMC Sierra, Chevrolet Suburban, Chevrolet Cheyenne, Chevrolet Tahoe, GMC Suburban, Cadillac Escalade, or GMC Yukon. The 1995 and earlier K trucks are very similar, but do not share the same retaining ring clip or cooler line design that were introduced in 1996.
Also applicable to some Holden branded GM K trucks in Australia of this same time period.
The eBay and Amazon search links below are paid links, for which I may be compensated and earn a commission, if you choose to buy the parts and tools shown in this video thru them:
GM 15112871 (supersedes GM 15996516) inlet oil cooler line: ebay.us/RdVXVg and on amzn.to/3CHewVi
GM 15724727 oil cooler line metal retaining ring clips: ebay.us/Qxum3t and on amzn.to/3u0CHdD
GM 15112870 (supersedes GM 15996517) outlet oil cooler line: ebay.us/AEMskz and on amzn.to/3CHGX5r
For the black plastic oil cooler line retaining clip GM 15725347: ebay.us/ZM6GB2
GM 12337820 plastic oil cooler lines zip tie: ebay.us/d4neXP
GM 463015 oil cooler line o-ring seal: ebay.us/EaN9Ku and on amzn.to/3JeYuV1
GM 15043741 oil cooler line connector fitting: ebay.us/mirqYi and on amzn.to/3R6F0Hg
Lisle 43890 fan clutch removal tool: ebay.us/EQg2Ht
And if I've saved you some $$ here, consider some coins for the coffee tip-jar! ko-fi.com/drshock
1996 1997 1998 1999 2000
Chapters:
0:00 - Problem overview
1:10 - Removing the upper & lower fan shroud
9:02 - Disconnecting the cooler lines from oil cooler
11:07 - Disconnecting the cooler lines from oil filter adapter
15:34 - Disconnecting the cooler line retaining bracket clip
16:26 - Removing the cooler lines from the truck
17:38 - GM service manual procedure tips
20:42 - Replacement GM part numbers
21:49 - Installing the cooler lines to oil cooler
25:36 - Installing the cooler lines to oil filter adapter
30:12 - Parts explosion diagram
30:41 - Torquing the oil cooler line fittings
31:36 - Re-installing the cooler line retaining bracket clip
#drshock #obstruck #obstrucks
Disclaimer: DrShock, the alias for the human content creator for this KZbin channel, is not responsible for any damages, injuries, losses, or liabilities associated with any repairs, upgrades, or maintenance performed on yours, or any other, vehicle whatsoever. No warranty, express or implied, is made as to the accuracy or completeness of any information provided within this channel. Viewing and using the “as-is" information of this channel is totally at your own risk. Always wear personal protection equipment and follow appropriate vehicle manufacturer service manual guidelines with original manufacturer parts only when performing any repairs, upgrades, or maintenance upon any vehicle.

[@BusyFingers]

Dear Dr. Shock, and all reading these comments. I’ve owned my 98 K1500 for just over two years, and in that time have watched countless instructional videos about it. There are many here on KZbin and many are good. But I can say now, with absolute confidence, that none compare to the quality, detail, patience and empathy with which Dr. Shock provides explanation and demonstration in his well edited, well presented videos. I can say this with such confidence because as of today, I, a self-declared amateur, beginner mechanic have successfully repaired oil cooler lines, oil filter adapter (with fittings) following the expert e-guidance of Dr. Shock. To celebrate, I’m treating myself to a Dr. Shock t-shirt and I certainly hope that proceeds of that end up in the Dr. Shock coffee fund. Thank you so much Dr. Shock.

[@mclagett1043]

Dr Shock could easily be a tech school instructor, or even a master mechanic/instructor of instructors for any major auto manufacturer... If you need a letter of recommendation, I got you!

[@andrewgardiner3484]

I like that you get as close as you can to the actual difficult areas to show what to expect. Some videos just blow right by those parts and only give an overall and misleading explanation of what just took them an hour to accomplish with no mention of how hard it was to do.

[@NWPencrawler]

Dr. Shock, great video. Love the detail, especially all of the OE numbers and correlation to the FSM. Also, great explanations all around. Makes me confident performing this on my own truck. Thanks very much!

[@danieljohnson4418]

Excellent video! I have found that your GMT-400 content is truly top-notch. Thank you for your contributions to our vehicle community.

[@ScottKelley-pk2mr]

Your video made this a fairly easy job, thank you so much.

[@lstackhouse345]

I watched your video and was able to replace my lines on my own probably saving me an arm and a leg from a shop.

[@ED-ti5tc]

I bought AutoZone hoses about 8 years ago. 2 years ago, I bout blowed up my 98 when one of the cooler lines separated at the crimp on the motor side. Dumped all my oil in no time. Great video!

[@fallenone6]

How did the auto zone lines hold up for you? Did you catch the leak on time before it did any engine damage.?

[@Coolchange447]

Great Video Very Explanatory Thanks And Alohaz From Kauai Hawaiian Islands 🤙🤙🤙

[@hoffmanshaven]

This video helped me. I'm trying to get the little clips back into the fittings what a pain!

[@dannystandifer9077]

Great video and details, thank you sir for your help.

[@jacklandismcgowan1413]

Great video.👍👍👍 Let us know when you find the perfect flashlight .😎

[@racencowboy26]

Great video

[@jamesburns-md9uz]

Thanks!

[@langjeff59]

Excellent Thank You

[@AGCGartner]

Did it just like this shows but in the bottom connection, there must be that white plastic "clip" that goes in there to prevent the oil leakage which I now have. Have to take it out & reinstall w/ the clip.

[@benkanobe7500]

Always first-class video with excellent and not superfluous narration. We all appreciate the GM OEM parts and links. Thank you! Is that the "Camper Special" option for a second battery? I would love to add that to my '96 Suburban as I have a Winch. I think it is NLA. Any guess where to get one?

[@DrShock]

Earlier years would have had a storage box in that location, but on the 1998 it was just empty. If you ordered the aux battery, or had diesel, there would be a second battery installed in that location.

[@nelsoncabrera93]

Thank you for the great video do you recommend power washing the entire bottom area with degreaser ? Especially the are where that clip is ?

[@DrShock]

Something paint safe and not an actual _pressure washer_ with water but yeah. A aerosol degreaser intended for engines, or brake cleaner works too. Now would be the time to clean this area out, if for nothing else to confirm the repair was successful.

[@danieljohnson4418]

I stripped the threads on my new GM radiator when attempting to torque the fittings to specification (before torquing the fitting, I started it by hand and made it hand tight using a wrench). Beware.

[@mattn6624]

Hey, Dr. Shock. So the end of the lines going into the filter housing under the engine do not need o-rings on them? Thanks for the video!

[@DrShock]

Nope, no o-rings on a GM OEM quick connect style fitting. The seal material is integral to the female port on the filter housing itself.

[@dastgahjoosh]

Any significant differences for doing this on a 2000 OBS Tahoe with the 5.7? Your part numbers match with the part numbers I get when I look these items up. I currently have the front end dismantled for suspension work and I think it might be a good time to change these cooler lines as they are leaking.

[@DrShock]

Should be identical for a Tahoe Limited/Z71 for model year 2000.

[@dastgahjoosh]

@@DrShock thank you!

[@freemanfornow264]

What do you use to clean an engine bay with that much crud? I've been trying to get mine clean and I cannot find anything that will touch it..... mine also has a lot of crusted on dirt from old gold mine areas that WILL NOT come off without scraping with lots of force and my ENTIRE undercarriage is coated with it!! Any advice will help and THANK YOU VERY MUCH for the clear concise instructional video

[@DrShock]

Thanks. What I used for this was initially Gunk engine degreaser, the spray on gel version. Give that a good afternoon in the sun and then rinse it all off with brake cleaner spray. You'll need several cans but it eats it right up. Wipe off the tough spots with blue shop towels. Once the leaks are stopped, eventually the engine bay heat will dry the rest up where it can be removed easier after another month or so and a re-application of the mentioned products.

[@freemanfornow264]

@@DrShock thanks I will give that a shot

[@BusyFingers]

Hi Dr. Shock. Trying to solve a mystery slow leak at the oil cooler inlet to the radiator. Lines are new (GM genuine), orings new. Is that fitting itself, where the cooler line connects to the radiator replaceable? Or does one have to swap the entire rad? Thank you.

[@DrShock]

The original GM/Delphi radiator didn't have replaceable transmission cooler connect fittings as best I can recall. O-rings only used on the engine oil cooler side of the radiator. Aftermarket models might vary. It's been awhile since I replaced one of these but here's a vid that might highlight the fittings on an OEM radiator - kzbin.info/www/bejne/nqqYgnVuZayWq5Y

[@BusyFingers]

@@DrShock Thank you, as always!

[@fallenone6]

​@@BusyFingerswas your lines leaking oil inside the radiator?

[@cocking1]

I have a 96 c1500 do I need the 96 service manual or should I get the 98 second edition

[@DrShock]

It's usually best to get the matching model year of your specific vehicle. The service manuals get very detailed, into content that does vary year by model year. But if you're in a pinch newer is better than older, just understand that there may be drawings and schematics that have changed.

[@BusyFingers]

Dr. Shock, if the point of origin of the oil leak in the cooler line is NOT the fitting, do the lines develop cracks, fissures in them? Is that the source? This over a period of 20-25 years, of course...My 98 1/2 ton has similar symptoms...Thanks for another great video.

[@DrShock]

What I usually have seen, on both gasoline and diesel cooler lines, is leaking at the crimp fitting between the aluminum and rubber. This particular truck is getting its third set over 24 years for that reason. But it can be a leak at the fitting due to o-ring failure. And it can be a leak in the rubber due to aging/cracking too. Rarely it will be leaking from the aluminum, but I suppose that too is possible with age and corrosion.

[@BusyFingers]

@@DrShock Thanks for the reply. In my case it definitely looks to be further down, closer to the crimp fitting, and making a real mess. I see from other comments and testimonials that it’s best to avoid the after market, especially for this particular part. Thank you again Dr. Shock.

[@darrennelson6803]

Whats the part number on the fittings that go in the filter adapter adapter

[@DrShock]

I added a link for that part into the video description.

[@darrennelson6803]

I ordered all my parts off your links!! Great video and wonderful description!!!! Subscribed!!

[@fallenone6]

Well explained video, helped alot. Did you use new fittings on the oil filter side or the same ones? Do i have to drain oil before replacing the lines? Can these lines cause oil to get in the radiator, if so does replacing the lines fix the problem?

[@DrShock]

If you have oil in the radiator with an integrated oil cooler, you need to replace the radiator as that indicates a likely internal leak between the oil cooler and main coolant core. These lines have nothing to do with that symptom. You do not need to replace the engine side fittings unless they are damaged/corroded. I would recommend doing this repair along side a regular oil change to reduce the cleanup involved.

[@fallenone6]

@DrShock if it is the oil cooler line since I don't have money for a new radiator will it be ok to by pass the oil cooler line instead of replacing the radiator? I don't do no heavy hauling with it.

[@DrShock]

First definitely do the additional diagnosis to confirm a root cause before buying _any_ parts. There could be more than one source for this than the radiator. I could never _advise_ someone to remove or disable a factory installed oil cooler, because the powertrain team for a particular truck configuration may depend on that functionality for more than just towing. But if you had to bypass it _temporarily_ until the budget allowed for a more correct repair, I could see that being workable for light duty on-road use.

[@fallenone6]

@DrShock would you happen to know what other causes would cause oil in radiator? And how would I know for sure If it is from the cooler line? I know for sure that my lines are leaking based on them being drenched in oil, so I will have to replace them regardless if I choose to not disable them.

[@DrShock]

None of the causes will be inexpensive to address. But oil in the coolant, _without_ any coolant in the oil, points to defective radiator (due to oil cooler containment failure), defective intake manifold gasket, or defective cylinder head gasket. In that order of probability. You should confirm this is engine oil you're seeing, as it's also possible that it's from the transmission fluid cooler, which would also point to the radiator (ATF cooler containment failure).

[@chrishemingway4491]

I use engine degreaser to clean up the engine and the residual oil that leaked because with brake cleaner it can sometimes effect the integrity of other seals I mean not saying I haven’t used brake clean before because of course I have but throughout the years of doing it I have learned to not use brake clean because other mechanics have told me I will cause myself more of a problem then I have so just a fyi

[@DrShock]

The thing with brake cleaner is not to buy the _cheapest_ one. Some of those have solvents that can take paint off. CRC and similar higher cost brands will not harm paint, and will not harm modern seals. If you're working on something earlier than the late 1980s, I definitely would not use it though.

[@fredglespie4045]

What to do if it’s leaking from the fittings?

[@DrShock]

Replace them (seal is internal to the fitting attached to the engine block). While not shown, the part number is in the description for this too.

[@andrewgardiner3484]

Why turn off the under hood light when what you should have done and you should ALWAYS do is to disconnect the negative battery cable from the battery whenever working under the hood.

[@DrShock]

We pull the hood light to not run the battery down as this procedure can take some time. You do _not_ need to disconnect power unless you are working on electrical or fueling components. In fact, many repair steps with more modern vehicles _require_ power as part of scan tool driven testing and diagnosis. It certainly will not hurt anything, other than resetting your state emissions test drive cycle, if it makes you more comfortable to do so though. But always follow the OEM service manual as closely as practical, as the engineers who designed the components will tell you if that step is necessary or not.

[@v34jj]

There is a screw in the star shaped fuel injector assembly can you help me because I have it unlocked

[@freemanfornow264]

Oh and by the way I'm currently in the middle of making -8AN lines to replace the factory lines..... only spots it can leak will now be either at radiator fitting or at oil filter adapter fitting..... stainless steel integrated braiding with nylon exterior braided lines... should be slick

[@hoffmanshaven]

How much do those 8AN lines cost? If you don't mind me asking. I am thinking I'll be replacing these Doreman lines sooner than later. Thanks