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

[@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.

[@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!

[@danieljohnson4418]

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

[@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.?

[@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.

[@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!

[@hoffmanshaven]

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

[@ScottKelley-pk2mr]

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

[@jacklandismcgowan1413]

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

[@dannystandifer9077]

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

[@superdoublekapowzler2383]

Just changed out a radiator, and had to grind 1/8" off each oil cooler line because the length between the o-ring and end of hose was too long. had to stuff a cotton ball in there and then grind. no leaks so far!

[@langjeff59]

Excellent Thank You

[@Coolchange447]

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

[@racencowboy26]

Great video

[@alexlozinski8965]

Hi, thanks for the great video. The printout you show at 30:13 shows one hose go from the upper rad fitting go to the upper filter adapter fitting. However, Figure 42 from p. 6B-38 in the 1997 FSM shows the opposite (for the 5.7l, albeit not very clear). I connected mine according to the latter with the longer inlet hose (GM 15112871) going from the top of the rad to the IN (lower) fitting on the filter adapter. I think you may also have done this in the video? Anyway, this is confusing me a little, I wonder if it actually matters?

[@DrShock]

Thanks. That's a good catch. The diagram is from the GM EPC (electronic parts catalog) so very generic and just used for parts identification (the illustration numbers map to GM part numbers in the catalog). Definitely go with the GM service manual drawing for your year and engine for how things wire / connect up. I showed that parts diagram just because it is useful to see all of the parts involved, but it is not intended to depict assembly and you likely have identified an error in the parts drawing in that regard. The GM hoses are labeled inlet and outlet as well, so you can't mix them up wrong.

[@alexlozinski8965]

@@DrShock OK I realized why I was getting confused! The figure I referred to shows a vertical filter adapter, so I think the lines cross only on the 2WD, but the routing you show at 30:13 is correct for K models.

[@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.

[@scotthawkins5078]

Is there any reason not to move the transmission holder(rod) out of the way? I can not get enough leverage to insert the new cooler lines into the oil filter adapter.

[@DrShock]

If you mean the bracing rod for the automatic transmission, you shouldn't have to remove that but as long as you reinstall it there's no issue temporarily moving it out of the way. You might also try some _light_ oil lubricant on the end of the line to ease insertion into the oil filter adapter fitting(s).

[@scotthawkins5078]

@@DrShock copy that. Thank you. I actually just fixed it with the help of my son. No leaks. Whoo hoo!!!

[@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.

[@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

[@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.

[@ricorivias1876]

Hey bud first off I love your videos , very helpful indeed, I have a question for you about a1998 Chevy Tahoe 5.7 I wanted to ask which lines go in the the other side of the radiator,it kinda smells like oil can you help me out?

[@DrShock]

Thanks. The cooling lines on the passenger side with this model and engine are likely the transmission fluid cooling lines.

[@thegoodobserver]

Got a question for ya. I have a 2000 denali with the 5.7L vortec. I noticed leakage around the upper fitting on the drivers side. Same ones you're working with here. When I trace the upper line it goes to nothing. Like the line runs down below the engine then has been crimped in some way. It's not connected to anything. Have you ever seen or heard of that before? Either way, your videos are helpful. Glad to have found your channel. Cheers man

[@DrShock]

Thanks. If you found the upper line crimped off, I would expect to find the lower crimped off as well. A previous owner may have elected to do an oil cooler delete rather than repair the problem.

[@thegoodobserver]

@DrShock Thanks for the quick reply! I just looked over everything in more detail and you're right. Guessing it's the radiator itself that's leaking. Just started watching your radiator replacement video and will give it a go. Thanks for the great content. You're a top notch teacher!

[@jamesburns-md9uz]

Thanks!

[@Bobthebuilder.69]

Good video. I started deleting the cooler lines on these obs trucks after I found that the factory oil cooler only lowered my oil temp about 10 degrees on a hot summer day. It's just not very effective when you are circulating your hot oil around in a hot radiator.

[@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.

[@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.

[@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!!

[@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?

[@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.

[@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).

[@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.

[@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.

[@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

[@user-uj3zk2cx8t]

Better off just deleting the cooler lines altogether and changing the oil filter adapter, will never leak again, ever. Oil cooler is not necessary

[@v34jj]

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

[@chinoreyna448]

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