Hayden Automotive678 Universal Rapid-Cool 9.5” x 11” Add-On Transmission Cooler – Not for Direct Replacement of the OE Cooler

First of all, the quality of the radiator itself is very very solid and well made. The heat sink fins are not too thin like many other aftermarket coolers. It’s very well made, and I’ve always had great luck with Hayden products, like their fan clutches, and transmission fittings.I originally bought a Chinese knockoff 40k trucool transmission cooler and I had to return it even before I even put it in my truck because of how poor the thickness of the radiator fins were. I could literally bend them with my finger nails. Did not feel comfortable about putting it in my truck. It was a massive leak waiting to happen.So I bought this Hayden cooler. It was actually cheaper than the 40k knockoff, and it’s much stronger and better built. I will be installing this tomorrow.EDIT: I installed these 2 days ago. Install was very easy, it look me about 3-4 hours because of all the custom mounting brackets I made, and all the hose routing with protective looms on it. But install was very easy and straightforward.I’ve been driving for the past two days with my scan tool hooked up to monitor the transmission temp, and I’m very happy to see that my transmission temperature does not go above 165F, even in slow stop and go traffic. Before I installed the cooler, my transmission temperature temp used to be around 190F-200F, but I’m glad to see how much cooler it is after the install.Very happy with the results, and this modification will definitely make my transmission last much longer.

I cannot say how I truly feel about this unit seeing it has only been installed for 2 weeks, but the mechanic that installed it stated it was a good model and brand. Stated it would do the job on my 1990 Chevy Silverado 5.7L engine with 4 speed trans. The internal cooler in the radiator ruptured and got water in the trans and flat ruined it. So I NEVER want that to happen again so I decided on and external one for my truck. I trust my mechanic and believe this will keep it cool and will NOT have another episode of water in the trans. Stated it was fairly easy to install and fit on the A/C cooler using the supplied hardware. Fits snug and so far so good. If you are looking for a external trans cooler I will recommend this one as my mechanic gave it a Thumbs Up..

Very good quality for half the price

great. arrived installed one week no leaks

Good quality product installed on a 2011 Acura MDX. I followed the video installation guide for the MDX provided by a well-known internet trailer company but they used another manufacturer's transmission cooler. I used the Hayden because I put a Hayden on my last car and had thousands of trouble-free miles with it -- plus, it was significantly cheaper and virtually identical.Here are some notes for anyone else looking to install the Hayden 678 on a 2nd generation MDX (probably also applies to Honda Pilot but not sure):-When I installed the provided hose on the cooler hose barbs, the first one slid on effortlessly but the second was a battle, even with silicone lubricant. I fought it for about 30 minutes and still couldn't get it to seat all the way down. I ended up cutting about 3" from the hose and then it slid on perfectly. I examined the interior of the cut section and it didn't have any flaws. I can't understand why I had such trouble.-As in the video I mentioned, you can do this installation without removing the front bumper/fascia by bolting the cooler it to the existing transmission oil cooler bracket, however, the flange on the Hayden cooler is not wide enough. You will need to fabricate some metal tabs to add width to the flange.-Also as in the video, I secured the right side using one of the provided plastic "zip tie" fasteners.-You have to remove the plastic skid plate/cover from just behind the bottom of the front bumper to access the transmission lines. I also had to jack the front of the car up and put it on jackstands to get some clearance to maneuver my arms.-There is a flat, roughly triangular metal bracket right below the transmission lines that is held in with three 17mm bolts. I removed the front two and loosened the back one and pivoted the bracket out of the way. Unless you have incredibly small hands and/or a lift, I don't see how you can do this job without moving that bracket but in the video he somehow does. There is also a small hose in the way that I disconnected 2 white clips from the car frame so I can move it around a bit.-I was concerned that there wouldn't be enough hose but there was about 9" more than you actually need for the MDX. Just be very sure where you cut so you don't come up short on one end. I used a pair of anvil pruning shears and they cut it beautifully.-On my 2011 (and in the video) the return line was the line that has a canister-style filter on it about 6" from the metal barb. Confirm though by running your engine, shifting through the gears, then shut the car off and feel the two hoses. The cooler hose is the one you will tie into.-Slipping off the hoses results in transmission fluid loss. I probably spilled about 1/8 quart doing this. If you have another person with you it might help but the area to work in is so tight I can't imagine it would help much. I slipped the new hose onto the newly exposed metal barb and then connected the old hose to the other length of new hose using the flared aluminum pipe Hayden provides and 2 hose clamps. Make sure you have the hose clamps on the hoses before you do the switch. You will need an extra hose clamp as well with this installation method.-When I turned on the car to check for leaks, everything was fine except I was getting a few very tiny bubbles at one of the connections on the flared aluminum pipe. I think the hoses on the Acura are about 1/16" wider than the 11/32" hose Hayden provides. I tightened the clamp down further and the bubbles disappeared.-Remember that you MUST replace not only the transmission fluid you spilled but also you must add a little bit more as there is now more capacity due to the new cooler and hoses. I added about 200 millilitres to start and will check after driving for 15 minutes and top up as necessary. Adding transmission fluid to the MDX is a minor hassle - you either need to have a funnel with a long flexible tube to fill via the dipstick or you need to open the fill port on the transmission which requires a long socket extension and some brute strength.I hope this helps someone!