bing tracking image
Q & A Icon

Derale Combination Transmission and Engine Oil Cooler Installation on a 2007 Chevrolet Suburban


I have a 2007 Chevrolet Suburban 1500, Z71, 5.3 litre. I tow a 31 travel trailer. I bought the D15902 kit from you and have some questions. 1. Is this the right kit for my needs? 2. How do I tie into the return line that hooks up to my radiator? 3. About how much transmission fluid and oil will I need to add after the install. 4. What other upgrades would you recommend since I am pushing the max tow rating? I have been very impressed with my experience with etrailer so far I just wish there was more instructions supplied with the Derale kit. Thanks for your help!


Expert Reply:

The Combination Engine Oil and Transmission Cooler you purchased, # D15902, will work great on your 2007 Suburban, provided that there is 2 inches of clearance below the OEM oil filter for installation of the sandwich adapter and installation and removal of the filter and there is room for the oil cooler hose to be routed when the sandwich adapter is installed.

Lets break the installation down to engine oil cooler and transmission oil cooler separately since the combo you purchased is essentially two coolers in one.

When plumbing the engine oil cooler you will use the 22 mm x 1.5 mm oil filter adapter included in the kit to install the sandwich adapter. Your OEM oil filter will then install on the sandwich adapter. If there is not room to use the adapter on your engine you would need to go with a Spin-On Adapter, # D35724, and a Remote Oil Filter Mount, # D15708. In this case you would then need to use a 3/4 inch - 16 thread size oil filter, like a PH8A on the remote filter mount. In either case you would then just route the 1/2 inch hoses from the oil filter adapter to the oil cooler portion of the kit and back to the adapter.

We recently installed a remote mount oil cooler on my Dodge truck, see install video link, and the additional oil needed for the larger filter, oil cooler and hoses is less that 1/4 quart.

When plumbing the Transmission Cooler portion of this kit, there are several ways it can be accomplished. One way is to use the Derale Snap-In Radiator Adapter Fitting for GM, # D13035, if your Suburban has this style of fitting going into the radiator. This adapter will install in the transmission fluid radiator return line port and you will attach a 3/8 inch hose from the fitting to the transmission cooler, then attach another piece of hose from the cooler to the return line that you disconnected at the radiator.

If your vehicle does not use the snap in style fitting, you could use two 3/8 inch compression fittings, # D13032, measure the outside diameter of the line to be sure. You would cut the return line with a tubing cutter and then install a compression fitting on each cut end, then attach the 3/8 inch hose from each fitting to the cooler. We have a video showing this type of installation, see link.

Finally, if you have a double flaring tool you could cut the return line, double flare both ends and use hose clamps directly on the return line to secure the 3/8 inch hose.

After installation of a transmission cooler the additional fluid needed will be less that one pint, which would be enough to replace any lost fluid and add any additional fluid needed. I would buy a quart just to be on the safe side.

The only other upgrade I would recommend is a power steering cooler. With a trailer that large you are most likely using a weight distribution system, which will transfer the tongue weight of the trailer across the vehicle and trailer axles for better towing and decreased sag at the rear of the vehicle. Some of this weight is transferred to the front axle placing additional load on the power steering pump. Adding a cooler to the power steering return line will help keep the pump cool and increase the life of the pump.

I would recommend going with the Power Steering Cooler, # D13200, along with a set of fittings that will install inline on the power steering return line, most likely the 3/8 inch barb fittings, # D98028, if you have a rubber return line, measure the inside diameter to be sure. If you have a steel or aluminum return line two of the 3/8 inch compression fittings, # D13032, should work, measure the outside diameter of the line to be sure. The additional fluid will be minimal here also a pint should be enough to replace and add any needed fluid.

expert reply by:

Products Referenced in This Question

Product Page this Question was Asked From

Q & A Icon

Similar Expert Q&A Pages

See More Q&A Expert Answers >>