need info on oil cooling line mod

[rustypig]

Some here have posted about replacing their oil cooling lines. Specifically looking for fitting sizes etc on the oil cooler and block fitting. Thanks

[triggerman]

rustypig
The 1998 Feature Articles and Product Reviews has 2 articles on 94 engine oil cooler lines. 1 by Jim Bigley and one by Chis McKendry. Its basicly where they fail and how to R+R the new parts (with PN's). I think I did read something about a guy puting in SS braided lines on his truck and the fittings were the hard part of the mod. This article may be the one that is in the 2002 Feature Articles book. If it is I think he goes into the whole fittings issue.

[rustypig]

I've got the 1998 issue. Jims article covers oem line r&R very well. I didn't see the other one in the 98 issue but will check again. I wasn't aware that the SS line mod was put into a 2002 article. Being a hydraulic mech I'd like to go the aftermarket route. I could take off the existing lines and build my own, but I'm looking to minimize downtime as the wife uses this rig daily. If anyone knows for sure about the 2002 article let me know. Knowing the size of the fittings would make things go way faster.

[slagona]

For those that have the 1/2" OD oil cooler lines (Pre HD Cooling mods) with 1/2" NPT Engine Block fittings, -8 AN SS Braided hose could be used to maintain the same diameter as the original oil cooler lines (7/16").

If your oil cooler lines are leaking only at the rubber hose sections - you can replace these hose sections yourself. This should be about a 2-3 hour replacement job and can be done with the original lines attached to the truck.

1) Cut off Rubber hose sections by cutting the aluminum tube as close to the crimps as possible.

2) Put a 1/2" ID Copper Flare Nut on the tube and flare the tube to hold the Flare Nut on the Tubing.

3) Put a Flare to 1/2" Female NPT adapter on the flared tube/nut.

The above can be purchased at any hardware store.

4) You will need four -8 to 1/2" NPT straight Adapters (such as Summit Racing part number SUM-220847). These go into the female NPT adapter on the end of each tube.

5) You will also need 4 -8 AN straight hose Ends (Summit Part # SUM-220890) and -8 SS Braided hose (10 ft section is SUM-230810) in order to make the hoses. Cut the hose to length, assemble the reuseable fittings to the hose and attach to the -8 pipe adaptors sitting on each end of the tubes and you are done!

The above parts from summit are summit brand, and total about $82 (10 ft is probably way to much hose - 6 ft should do it...). The hardware store parts total about $10.

There are a few things to worry about here. When cutting the crimps off the tubes, metal shavings can get into the engine since the tubes are still attached. However, if you cut it correctly and quickly, there should be enough oil in the cooler and lines to "flush" the shavings out. Also, you are flaring aluminum tubing. This may not work correctly for all cases.

If you want to take the entire original assemblies off the truck and replace them, you can start with 90 degree Pipe to -8 adapters, such as Summit # EAR-982288 to put into the engine block. I have not tried this, so I don't know if you have room to put both adapters on the block, clearance from the cross-over, exhaust, exhaust manifold, ..... From there, you could make your own hose same as above. It get's a little trickier to connect to the oil cooler. Someone else will have to give you the fitting size for the oil cooler.

Summit now carries Earls, Russell, Summit, and Aeroquip hoses and fittings. I went with the Summit brand for my last project, they are about 10% cheaper than the others and seem to be comparable quality.

If you decide to take the entire oil cooler lines off in order to enhance them, you can add at least 2 more hours to the R&R - especially if you have 4WD. I had to drop my front differential in order to get the new assemblies on.

If you are going to have the hose sections replaced, make sure the orientations of the aluminum tubes are correct before the hose is crimped on - otherwise it will be difficult (or impossible) to re-install the lines (hose may have to "twist" to install if the tube sections are not oriented correctly).

If you have the HD Cooling Mods or a post '97 system, you should probably use -10 hose (9/16" ID). System is pretty much the same as above, but using 5/8" ID Flare Nuts going to 1/2" NPT fittings. The Engine Block fittings are 3/4" NPT for the HD cooling engines.

Hope the part numbers help - Get a Summit Catalog if you don't already have one - they are great references - plus prices are ok. Also, get an Aeroquip catalog - that also gives instructions for assembling the hoses.

--Scott