An oil cooler hose supplies the transmission and engine oil with a way to circulate and cool down. This hose runs from the individual parts to the radiator in the front of the engine compartment. Without the oil cooler hose the engine, or the transmission, will get too hot to operate smoothly, and burn up. Leaks in the oil cooler hose need to be attended to immediately. Here are some steps for the average do-it-yourself mechanic to replace the oil cooler hose in a few hours.
Step 1: Locate Oil Cooler Hose
Before you start to disconnect any lines or hoses, you must make sure you know where they are. Follow the oil cooler hose from the transmission or the oil pan, and trace its route to the radiator. You may find just a single line or a dual line, depending on the type of vehicle you own.
Step 2: Disconnect Hose from Radiator
Slide a drain pan underneath the oil cooler hose connection on the radiator side. Use a wrench to loosen the coupling, turning in a counterclockwise direction. Be ready for some oil to leak out of the hose. Keep in mind that it may be a little warm to the touch.
Step 3: Disconnect Hose from Oil Pan
Depending on where the oil line is going to, disconnect the line from either the oil pan or the transmission. Use a wrench to loosen the coupling and remove the line.
Step 4: Remove Line Holders
If the oil cooler hose is kept secure with a line holder, use a small socket to remove the retaining bolts. The oil cooler line should then drop away from the frame and the clamps holding it in place.
Step 5: Remove Oil Cooler Hose
One of the hardest parts of replacing the oil cooler line, is removing it from the engine compartment. The oil line is going to be weaved in and around different parts. Make sure you do not cut the line when removing it. You may need a spare some day.
Step 6: Install New Oil Cooler Hose
Once the old oil cooler hose has been removed, clean off the attachment points. Weave the oil line in through the engine parts again, and line it up with the line holders. Attach it to the line holders, and secure them in place by driving in the bolts with a socket wrench.
Step 7: Connect Line to Couplings
With the new hose lined up with the couplings of the radiator and the terminal point, make the connections by threading the couplings onto the lines. Tighten them down with a line wrench, and make sure they are not too tight.
Step 8: Refill Oil Reservoir
Once the oil cooler hose is connected, you need to refill the reservoir with any oil that leaked out. Fill the oil and then start the car. This will allow the oil to circulate through the oil cooler hose. Check to make sure there aren't any leaks along the line. If there are, tighten the couplings a little more.