What Tru-Cool heat exchanger would be best suited for my vehicle?
Please refer to the Tru-Cool brochure to match your vehicle to the heat exchanger that best suits your cooling needs. Due to liability issues, we can't recommend a heat exchanger.

What is the thread on LPD-4739?
Thread is 5/8" - 18 UNF 2B thread (3/8" inverted flare).

At what temperature does the thermal bypass activate?
The thermal bypass starts to open at 180° F, and is fully open at 205° F.

Do you have heat exchangers with ANS fittings?

Do you have heat exchangers with 1/2" hose barb fittings?

How can larger tube & fin coolers offer less cooling?
Bigger isn’t always better. Tube & fin designs are inefficient and have a lot of dead space, while the Tru-Cool stacked plate design puts most of the oil close to the surfaces that are in contact with passing air. In fact, when it comes to cooling, the Tru-Cool cooler is up to 30% more efficient than tube & fin designs.

Which cooler should I use for a diesel application?
In most diesel applications, the transmission line is large. The cooler’s fitting should not be smaller than the lines. The smaller lines will restrict the transmission fluid flow.

The fittings supplied do not work with my application. What should I do?
We have supplied fittings for the four most common applications. Compression fittings can be purchased separately from your local distributor. Part numbers are as follows:

  • 735-9139 for 5/16 lines
  • 735-9140 for 3/8 lines

Where should I install the cooler?
If possible, locate the cooler in an area where it will be exposed to ram air. This helps maximize cooling. Install the cooler in series and downstream of the radiator in-tank oil cooler. This maximizes heat transfer and decreases trans- mission warm-up times in colder weather. Most OEM installations are plumbed this way.

How should I mount the oil cooler fittings?
Fittings can be located up, down or sideways. This advan- tage, plus their compact design, makes installation of our coolers quick and easy.

Should I disconnect the radiator in-tank oil cooler when I install a Tru-Cool cooler?
We don’t recommend disconnecting in-tank cooler. If you are going to disconnect, consult OEM. The in-tank cooler offers additional cooling and helps preheat the transmission. In colder climates, the in-tank oil cooler should never be disconnected from the system.

Will putting an oil cooler in front of the radiator increase the engine operating temperature?
Not normally. Putting an auxiliary oil cooler system in the system decreases the temperature in the radiator in-tank oil cooler, and this in turn puts less of a load on the radiator. From a total system standpoint, the engine operating temperatures should vary little from where they were before the oil cooler was installed.

Will installing an oil cooler affect my vehicle customer warranty?
It could, depending on which cooler you install. Vehicle manufacturers do not normally approve of the installation of tube & fin coolers, since they are very flow-restrictive. LPD oil coolers, though, are virtually the only cooler now being used for OEM factory installations. Contact your local dealer for approval.