for installing the 2500HD fans, I needed to extend the oil cooler lines.
coming from the rad are two 1/2" OD steel lines that need to be re-routed. One method is to cut the metal line, stuff a hose over it and clamp it in place - that's chicken sh*t.
A better method is to use the appropriate fittings to add a section of hose so the lines will fit the new fan shroud.
compression fittings are good for this project for a couple of reasons.
I used the following:
2 ft of 3/8" ID trans oil line [have leftover]
8 worm clamps
4 x 3/8" hose barb to 3/8" FIP straight
2 x 1/2" OD compression to 3/8" MIP elbow
2 x 1/2" OD compression to 3/8" MIP straight
get extra ferrules in case you have a leak and need to re-press any connections.
I used DOT-approved compression connections. (some might have inserts for plastic tubing that you'll have to pull out)
picture was taken from the front of the vehicle, looking down just inside the battery tray
the upper line is cut about 1.75" straight out of the rad, and elbowed "out" from the line.
the lower line is cut after the line elbows, and elbowed "down" from the line.
when you cut the line, be SURE it's at a round spot - if too close to a bend, it will not be round and the fitting will leak, at best.
read this about working with compression fittings:
How they Work:
As the name implies, compression fittings form a tight seal by applying a compressive force to the pipes and pipe fitting. The fitting is compressed against the pipe with a force sufficient to eliminate all space remaining in the joint, thus preventing fluid from leaking.
The compression fitting is composed of an outer "compression nut" and an inner ring called a "ferrule" or "olive" in the UK. This is usually made of brass or copper. When the nut is tightened, it clamps-down on the ferrule, causing it to conform to the circumference of the pipe. Ferrules vary in shape and material according to the pipe material. To work properly, the ferrule must be oriented correctly. Typically the ferrule is fitted such that the longest sloping face of the ferrule faces away from the nut.
It is important to remember to not apply joint compound or teflon tape to a compression fitting's threads. The compression is the means of sealing the joint, not the sealing of the threads themselves. Pipe compound or teflon tape will frequently lead to a leak in the fitting by causing the fitting to loosen as a reaction to the compression. In a standard threaded connection, pipe compound and teflon tape act to seal the threads from the water pressure. In a compression fitting, the ferrule will push against the lock nut. Joint compound and teflon tape will act, in a compression fitting, as a lubricant rather than a sealant and cause the joint to leak.
In addition, it is critically important to the integrity of the fitting that excessive force is avoided in tightening the nut. If the fitting is overtightened, the ferrule will deform and cause leaks. Overtightening is the most common cause of leaks in compression fittings. As a general rule, a compression fitting should be "finger tight" and then tightened 1/4 turn with a wrench. The fitting should then be tested, and if slight weeping is observed, the fitting should be slowly tightened a bit more until the weeping stops.
I hope that's clear, I'd be happy to answer anybody's questions