Remote Oil Line Hose Diameter
 

Since I've got the '98 Jimmy up on jack stands in the garage from troubleshooting the P0420 I decided today would be a good time to replace the leaky remote oil lines. I did a lot of reading about various solutions people have tried, both on this forum, on the S10 Forum (of which I am also a member), and various other places on the Internet. I didn't want to spend the money on having custom hydraulic lines built so I didn't go that route although it is very impressive. I also don't have the skills for braising so I crossed that off the list. I didn't necessarily want to replace newly-leaking lines in a couple years so I skipped buying the replacement crimped lines. I chose the method outlined on the S10 Forum...

Repair your leaking oil cooler lines! (Pics fixed) - S-10 Forum

I went to NAPA to get all the parts so I would have them on hand. I took the oil lines and oil filter adapter off the block and got everything out where I could clean and degrease them. The adapter went back up in place with brand new gaskets. I was careful to torque the bolts down to factory spec.

Things got weird when it came to the oil lines. When I removed the lines from the filter block behind the bumper I found that there were two sets of washers on the end of the lines. There was the normal set of rubber washers in a steel enclosure and also a set of rubber washers covered in some type of silicone. That made me suspicious that someone previously had done some kind of work on the lines.

I cut the aluminum crimps off the lines and cleaned them up per instructions. I measured the replacement 1/2" hose to cut it to length. Before I cut the hose, however, I checked to see how well it fit onto the aluminum lines. It was way too large. The hose I took off the aluminum fittings said it was 13/32". At that point I stopped and went to AutoZone and just bought the Dorman replacement lines.

Are the factory lines actually 1/2" or are they 13/32"? I suspect that the truck had some kind of aftermarket replacement lines. The lines were not double-crimped like what I've heard of factory lines; they are triple-crimped.

thats a pretty cool fix, just keep a eye on the hose clamps as they will loosen up as the rubber hose smashes over time. thats pretty much where they always leak too is on that crimp.

when i bought my 93 they were leaking i did the even more fullproof repair and bypassed them and threw them in the trash. and just mounted the oil filter to the block but i also ripped out my factory front diff so lot of room to mess around

I didn't do the hose clamp rebuild on the lines. The hose that was recommended in the post from the S10 Forum was too large for the lines that were on there. I didn't want to waste any more time on it so I just got the Dorman lines from AutoZone and called it good for now.