How To Replace Upper Engine Oil Cooler Inlet Hose 1992-99 GMC K1500

With the vehicle safely raised and supported, we're gonna come right under here to the oil filter. Remove the oil filter. That's gonna give us better access to where the cooler lines are. Just hold on to these. It's right out of here. Get our nice recycling bucket here. The next thing we're gonna do is remove this bolt right here. Use your 18-millimeter to loosen up this top bolt here. Let's see if this moves. Even if that moves, it just doesn't move where I need it to. Here we are. Let's use our 15-millimeter, we're gonna remove the both of these, and then we're gonna loosen this one and loosen the one on the other side. Looks like we don't have to loosen them, even better. Now, if you look up along the front or at the top of the front differential, you're gonna see a bracket that holds your two oil cooler lines together. On the driver's side of that, the area that you can't physically see, there's a 13-millimeter nut. We're gonna remove that nut completely. There's a nut. Let's see about getting off the backside of that bracket. Put those two together, set them aside.

If you come underneath the skid plate, you're gonna be able to see this wire tie. Go ahead and snip that right off of there. So, once I broke it free with the wrench, I'm just gonna use my pliers because it's much easier to just continue grabbing this way. We'll get this line completely off of here and then we can move along to the top. Looks like it's pretty close. Here we go. Now that that first line is out of the way, we can make our way up to the top one. So, now if you're just doing line on this, you shouldn't necessarily have to remove this. There's little tabs that you can usually squeeze and then you can pull the line out. Ours is broken, so we have to do this. Nice. Easy peasy. Let's go ahead and take off this hose right here. Pull it right off of there. There should be one leading to right here as well. We don't have one, but go ahead and take that off as well. Use your 13-millimeter on this bolt and remove it.

All right. Let's grab this up and out of here. Set that aside. We've got our 21 wrench on here, let's see if we can break that free. If you need to use a little bit of penetrant, it would probably be helpful. This one is actually fair. Awesome. Okay. Let's grab one of those. See if we can get it to work its way up and out of here. There we are, friends. If you look right along here, you're gonna see a little plastic lip. There should be another one right here. Ours is broken. So, what I'm gonna do is I'm gonna squeeze the one lip that I can and align together. Apply a little bit of pressure and then we're gonna try to get this off of here. This is gonna be pretty stuck, so I'm just gonna use a little hammer. I'm gonna give it a bonk and see if it pops free. There we are.

Now, as they say, there's more than one way to peel a potato. You can either put this in from the top and then down, or you can go from the bottom and up. I'm gonna go from the bottom and up. So, with that said, I taped off the end to make sure that no dirt and debris can get inside because obviously, I don't want anything inside this line. At this point, I'm just gonna go right along the other line that I have in here and then just run it right up and along. It's gonna make its way all the way up to the top portion of that radiator just like this, this one like that. And that looks perfect. We'll leave it just like this. And now we're gonna continue on to putting on our fitting. Start it in there by hand. Use your one-inch socket with a ratchet. It's gonna take a little while, but just turn it right in there. Okay. That feels good right there. I'm just gonna take a look. Yeah. Looks like I'm about halfway down the threads. That's perfect.

So, now we're just gonna grab this little plastic piece by squeezing the ears and we'll pull it right out of there. At this point, this is gonna slide right over the top of that line. There it is. Slides right over. You can see that the ears went over the knob on the line. Super important. Make sure this is nice and clean, and then we're gonna slide it in. Okay. It's lined up. Push it right in. Make sure you give it a nice tug. If it comes right out, you know it's not locked in. This feels great. Now, for this one since we're not replacing this fitting, I'm just gonna put a little bit of this tape over it like that. That's gonna help make a good seal. Line this up so it's nice and straight, and then we're gonna screw it right in. Now, to get this line on, we went ahead and we took off the fitting just like we did the other side. So, to continue, we cleaned up the fitting threads, we put on a little bit of this thread sealant on there. We've got our new clip, just slide it right over the line. And then we're gonna install this the same way we installed the other one. Slide over the line. There we are. Okay. That's in. Give it a nice tug. Yeah. That's going nowhere. That's back on here.

The next thing we wanna do is put the oil filter on here. It's a great idea to do the oil change while you're at doing all this. If you are, of course, you wanna replace the oil filter and then put a little bit of lubricant on the O-ring. This is just a test vehicle, so I'm just gonna put this one back on. I cleaned down the O-ring and added a little bit of lubricant. Now, it's time to get this bracket back on here with, of course, our 13-millimeter nut. It goes right up here to this bracket that holds both those lines. It should go through the hole. Now, we're gonna put the bolt on the other side and we'll snug it up. Okay. That's nice and tight. The lines are secure.

All right. So, we removed a wire tie from up here, so let's go ahead and put one back on. That's just gonna keep these lines so they're right up against each other, not moving around too much. Trim off the excess, of course. Let's get our protective tape off of here. Make sure your gasket is still on there. It's a good idea to put a little bit of lubricant on it. Here we are. It's important to make sure you start this in by hand. Put this all goes down like that. Okay. That's nice and tight, the line doesn't move around. Perfect. Slide this back in here nice and easy. Your little hose up on there. Put the clamp back where you got it from, it's gonna hold it on there securely. That feels good. Do the same to the other one, assuming you have one. Now, we're gonna tighten up the mounting bolt right here. Sweet. Okay. So, this all looks great.

The next thing you would wanna do, of course, is to clean everything down. You're gonna check your oil level to make sure you still have oil in it, run it for approximately a minute, turn it off, and then recheck that oil level. At that point, you're gonna know exactly how much oil you should add. Get it right up to that maximum line and then take it for a road test.