Hayden Install w/ radiator trans cooler bypass
 

Hello i snapped some pics while doing my trans cooler install. i bypassed the factory radiator cooler after reading about the horror stories. anyways heres a quick write up.

I purchased this runner about 2 weeks ago. Dont know much of the maintenance history but i got great deal. I decided to drain the atf fluid and refill with toyota dex III atf. The manual says 2.1 quarts but i drained about 3.5. I added 2 quarts and it was low after a 10 min drive so i added another 1.5 and now its happy.

I decided to go with the hayden rapid cool 678. got it for cheap at my local auto parts store. It looks identical to the TRD based on pics without the fancy mounts. Also manufactured in Canada. you may want to go with the tru cool if you live in an area that sees low to freezing temps.

Tools i used:
-12mm socket for the skid guard and radiator/chassis guards
-vice grips for the hose clamps
-philips screwdriver for hose clamps
-flathead screwdriver for the front grill tabs
-xtra 3ft of hose. hayden says the hoses need to withstand 250+ deg temps and i read around here that the pressure is about 40psi. i bought some nice goodyear hoses rated at 250psi..
-knife
-atf fluid

pic of the tools
http://i144.photobucket.com/albums/r...d/IMG_0240.jpg

start off by removing the skid plate
http://i144.photobucket.com/albums/r...d/IMG_0234.jpg

then the radiator/chassis guard. after the bolts are off you will find that its still stuck. there are 2 hooks in the front and a slot in the rear thats holding it in place. a combination of pushing up and towards the front of the vehicle will release it.
http://i144.photobucket.com/albums/r...d/IMG_0235.jpg

remove front grill. On my 02 it is held on by 6 tabs. Take a flathead screwdriver and lightly push on the tabs and lightly pull back so its not snapped in place. after you do this for all 6, you can pull the grill towards you and off.

mount the trans cooler with the hoses on. i found it easier this way. i used the supplied mounting tabs. make sure you use the foam pieces in between the cooler and ac/condesor so its not slapping around.
http://i144.photobucket.com/albums/r...d/IMG_0237.jpg

route the hoses down. i reused these rubber hose guards from the factory hoses. i placed them where there are jagged edges to prevent it from cutting the hoses.
http://i144.photobucket.com/albums/r...d/IMG_0238.jpg

once your down there disconnet the trans fluid send and return line, the two small hoses, from the bottom of the radiator with the vice grips. I used the plugs supplied with the hayden to plug these up.

follow the hoses back and disconnect the other 2 clamps that hold the hoses in place. they are connected to this
http://i144.photobucket.com/albums/r...d/IMG_0236.jpg
they are stuck on there pretty good. there is very little room for your hands to get to them. i decided to chop em off with a knife. careful not to damage the metal. i like to wipe it down before i install the new hoses. place your new hose clamps strategically so you can get a good angle to tighten them.

connect the hoses, tighten the clamps and your done. start her up and check for leaks. check if your atf fluid is low. add necessary amount. I chose to drain and fill with fresh fluid. I left the skid plate and guard off for 2 days so i can keep an eye on everything. Its been all good! :nerd:

Dont know how much of a good idea that was since the Hayden coolers dont have a bypass...for cold morning starts. Thanks for sharing the pics.

He's in southern Ca, probably never even rains there hehe.

I never bypassed my factory trans cooler when I added my Hayden and never had any problems. I don't see the reason for doing a bypass. Isn't the reason for adding the additional cooler to provide added fluid and cooling fins to help your tranny run cooler....

The reason for bypassing the factory cooler is to protect your tranny if the radiator internal cooler bursts (there have been a lot of cases of that happening to 3rd gen 4Runners in the last few years.) Do a search on here and you'll find quite a few people that have ended up with coolant in their transmissions because of this.

Ahhh...thanks for explaining. Guess I've been lucky. Maybe this happens in cold weather climates

Most of the failures I've read about have not been in cold weather climates.

It would have to be really, really cold for any weather issues. Unless he parks it outside in 30 below, jumps in the truck-runs it for 20 seconds and the drives off full throttle, he should be fine.

Besides, if there were cold issues, he wouldn't go very far very fast as the oil would still be making its way around the transmission.