Transmission Cooler Installation - 2004 Chevrolet TrailBlazer

content loading

Customers compare D13503 to these similar products

Products Featured in this Video

How to Install a TranSMIssion Cooler on a 2004 Chevrolet TrailBlazer

Today on our 2004 Chevy Trailblazer we'll be installing the Durale Series 8000 Plate-fin Transmission Cooler Kit, part number D13503. Before we can begin installing the cooler, we'll fist need to go ahead and gain accessto the front radiator and/or A/C cooler. To do this we'll go ahead and remove the frontbumper cover and the grille. Starting with the front bumper cover underneath, we'll goahead and remove the two fasteners here on the driver's side, securing the bumpercover to the bumper structure. We've got a push-pin fastener we'll remove first andthen a bolt. Now we'll go ahead and repeat the same process on the passenger's side.Next we have four push-pin fasteners located near the license plate bracket that willneed to be removed.

Now, we've got three more fasteners that will need to beremoved in order to remove the bumper cover; however, it's easier to remove thesefasteners after we remove the grille, so we'll go ahead and do that next. This justhappens to be the nature of the beast when disassembling. Using our trim tool or aflat-bladed screwdriver, we'll carefully pry the grille away from the core supportwhere it's secured. These are all a wedge-style fastener, so we'll just need to be carefulnot to break them. Now that we've got the grill removed you can go ahead and see thefasteners underneath the chrome trim; they're not visible when removing.

All right,we'll go ahead and set the grill aside for reinstallation later. Now we'll go ahead and remove the two bolt fasteners on the bumper cover and thenthe center push-pin fastener. Now with our fasteners removed, we'll go ahead andremove the bumper cover and set it aside for reinstallation later. Now we'll go aheadand get back underneath the vehicle and locate the transmission cooler lines. As youcan see, we have an inlet and an outlet coming into the radiator here; now we'll beadding to this.

We'll need to cut the transmission cooler line, so that we can double-flare each end to install our hoses. The easiest way to do this is to first remove the linefrom the radiator. We'll remove the clip cover and then the small C-clip that securesthe line into position. Now we can go ahead and remove the manufacturer's coolerline from the radiator. However, before we go that far we'll go ahead and startassembling the oil cooler.

To do that, we'll first install hoses. Well first remove the protective cover caps off theoil cooler and now we're ready to install the oil cooler hoses. We'll be installing thehose that comes with our install kit, and I'll be using an additional piece, as the installhose is not quite long enough for where we're going to mount it. The additional piecewas taken from the Durale High Temperature Replacement Hose, part number D13003. Now with the hoses installed, we'll go ahead and slide on our hose clampsand tighten them down. Next we'll go ahead and install the Durale Universal RigidMount Kit, part number D13002. This kit includes multiple brackets and fasteners.Well be using two of the bendable metal brackets to assist in securing our oil coolerto the radiator core support. Next we'll go ahead and install the brackets, using thesupplied fasteners to secure them. Keep in mind to allow them to be a little loose untilwe get them in place. Now with the brackets attached to our cooler we'll go ahead and put our cooler inposition on the vehicle. Well feed the hoses in first, down between the power steeringcooler and the radiator, and under the vehicle to the back of the radiator as we workthe oil cooler into position in front of the air conditioning condenser. We'll go aheadand take the bendable brackets and attach them as necessary, using the suppliedfasteners to secure the oil cooler to the core support. Now with those two fastenerssecured we'll go ahead and completely tighten down the two that go to the oil cooler.We'll choose the driver's side line to remove, add flared fittings to the line and add ournew hose. Let's keep in mind this transmission is full of fluid. Next were going to goahead and make room for the hoses that are coming underneath the lower air dam.Well simply take a plastic rotary tool into our drill and notch out the plastic. Thiscould also be done with a pair of side cutters, a small saw blade, or maybe even autility knife. You can see our lines will now fit through without pushing the air damout of place. Next we'll go ahead and mark out where we'll cut our steel line, and we'll even take acouple of extra inches out to allow for the addition of our new oil cooler hoses. Nowwith our markings made we'll go ahead and take our tubing cutter and cut the line.Next I'll go ahead and cut out the section that we have already previously indicated.Now we can go ahead and, using our double-flared toolkit, flare out each end. To flareout an end you'll need a set of double-flaring toolkit. If you don't have one or access toone, in most cases it can be rented from a local auto parts store. To flare the line we'llfirst need to figure out what size line we have it should be indicated on the flaringbar. Once we do that we can go ahead and secure the line to the bar loosely. Nowwe'll take the appropriate cup size, which can be determined by the stem of the cupfitting into the line the larger the better. However, as you can see when you go toolarge, the stem will not fit in the ilne, so we'll go back down one size. Now we'll usethe width of the cup to determine the width of the line that we'll need to stick aboveour flaring bar. After we've made that adjustment we'll go ahead and secure andtighten down the flaring bar. This will hold the line in place as we make the doubleflare. We'll go ahead and put the cup back into the line and then take the flaring cone,smashing the cup down into the line causing the single flare. Now we'll go ahead andremove the cup and just use the flaring cone in the line to make the second flare forour double-flared line. Now with that completed we can go ahead and remove it fromthe flaring bar, set it aside, and repeat the same process on the other side of our cutline, which will still be on the vehicle. Next we'll go ahead and take our hoses, match them up to the lines, and cut off anyexcess. Well go ahead and slide our clamp onto the line and then we'll slide the hoseonto the line. As it will be difficult to get over the flare, I recommend you use sometransmission fluid as lubricant, both on the line and on the hose. Now that we have our first line onto the hose, we'll go ahead and take the clamp, put itinto position and tighten it down. Next we'll go ahead and repeat the same process onthe other side. Now with both hoses onto the lines we can go and reinstall the line onthe driver's side. We'll reinstall the C-clip and the clip retainer. Next we'll go aheadand take a couple of zip ties and secure the two hoses together. Now with that done,before we start reinstallation, we'll go ahead and start the vehicle, run it until thevehicle gets to operating temperature, and check for leaks. While doing that you alsowant to check your fluid level and top up as needed. While we're checking for leaks, Ialso recommend to check the owner's manual for proper fluid and fluid levelspecifications. Now that we've verified that we don't have any leaks, we're ready to goahead and start reinstalling the front bumper cover and grille. Now with everythingreinstalled, the will complete the installation of our Durale Series 8000 Plate-finTransmission Cooler Kit, part number D13503, in conjunction with the DuraleUniversal Bendable Mounting Kit, part number D13002, and the Durale HighTemperature Replacement Hose, part number D13003 on our 2004 Chevy Trailblazer.

Questions and Comments about this Video


Awesome help... Replaced the power steering cooler from this video. Thanks You!

Etrailer Expert
Reply from Patrick B.

Glad our video was helpful. Let us know if you need anything else.

Info for these parts were:

Employee Zack K
Video Edited:
Zack K
Employee Andrew K
Video Edited:
Andrew K
Employee Joshua S
Video Edited:
Joshua S
Employee Sue W
Video Edited:
Sue W
Employee Nicholas E
Test Fit:
Nicholas E

At we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.