I started the hose install today:


I started with the top 'send' line from the transmission:


I routed the send line in this photo with the A/C lines. I decided to piggyback another users' idea and place radiator tubing along the bulkhead walls to prevent the hose from chaffing against the metal:Fortunately for me, this excess radiator hose was on top of a trash can at an auto parts store as I entered. As I exited the building, I just picked it up and used it as a hose protector.

Here's the other side (engine bay) of the bulkhead:


I installed the hose end from the top fitting on the cooler to this metal line:

Another angle:


Since I was installing a new hose, I no longer needed the hose that came from the manufacturer, so I had to cut it to assist in the removal of the hose from the fitting:


Only this amount of fluid came out after removing the first cooler line:


Here comes the ghetto part: I know I need to flush out the cooler portion of the stock radiator so no old transmission fluid mixes with the coolant/antifreeze in case the wall separating the two is ever compromised. What could I do? I had no proper tools to flush out the tranny cooler part of the stock radiator. Here was my 'fix': B&M's Cooler hardware includes barbed hose fittings that you can screw together. I used the larger fitting:

I inserted the large metal fitting from the kit onto the original hose from the radiator and tightened a hose clamp around it. I screwed the other metal fitting onto the first. I clamped a second piece of hose I bought at AutoZone to the second fitting and brought that new piece of hose to the top of the radiator.....:

Here's a close-up photo of the two fittings from the B&M kit together and hoses connected to them:

The ghetto part is this: I knew I had to use water to flush that cooler portion out. I brought out a large cup of water, put some of the water in my mouth, put the hose to my mouth and forced the water down the hose with all my might. I do this twice and found it very difficult to push the air through with just my lungs. I came up with a better idea.

In this photo you will notice a bicycle pump next to the engine oil dipstick. I brought it out, placed the end you would normally place against a tire valve stem, against the hose I forced water down into and starting pumping the tire pump. It worked like a charm. All the air was forcing the old transmission fluid and water out. I could not see it coming out, but I heard it and my little helper (daughter) was able to see when the 'red stuff' was no longer coming out and then she said it was 'white' (water).....or mostly water.

I left the stock hose on the other end of the radiator and it had been aimed down to the drip pan as I forced the air into the cooler part of the stock radiator:


I was off the target by a bit. I should have pushed the drip pan to the back of the vehicle a bit more. I got some 'Pink Milkshake' I artificially produced on my own onto the cardboard I had laid down on the parking lot to catch any mistakes I might make.

Here's the result of tap water being forced into a hose to push out the old transmission fluid out of the stock radiator:

After that, I brought a section of auto parts store-purchased 3/8" ID (Inner Diameter) into the mix. I closed off the send and return metal fittings off the stock radiator with this hose. I decided to bring it behind the power steering cooling tube just for s**ts and giggles.

The lower cooler hose:


And the routing. It is the hose on the bottom:


The completed install:


I went out on a lazy sunday drive after that with the kids. I had checked periodically for leaks and felt the heat from the B&M cooler against my hand and it was working just fine. Sweet Mod. Kudo's to those forum members out there for submitting photos and their knowledge for all, including myself, to share. I would have never known this was a problem on this generation.

When the time comes, I am going to install a pro comp 8 or 9 inch radiator fan and maybe a thermister and switch for automatic on/off operation......but I just might make it a manual switch instead and turn it on and off when I feel the need; i.e. stop/go traffic/hill climbing/long and steep grades. Amazon has some for a good price.

Hope that helps somebody out there.

BigFish or anyone else, did you use 8' of 3/8 hose for the install or 4'? Also did you used the 5/16 hose at all or can I use that instead of one of the 4' of 3/8 hose. I'm going to start this tomorrow and need to have all the materials prior to starting. Thanks.

Also do I need to force the fluid out of the stock cooler? Or will it drain out when I remove those lines?

SCRunner12:

I went to AutoZone and bought 3/8" in diameter hose at four feet just in case the hose supplied with the 70268 B&M cooler was not long enough.

It's always better to have more than you need than not enough.

I used both the supplied 5/16" and the bought 3/8". Obviously the narrower diameter is a tighter fit, but just using the transmission fluid as a lubricant to slide it on the nipple end of the send or receive line helped during the install.

The reason I forced the remaining transmission fluid out of the radiator was in the remote possibility the separation between the radiator and transmission oil cooler portion ever weakens to the point of opening up, then the transmission fluid and coolant/antifreeze will never mix and I won't have to replace a transmission or an engine. As in the photo, I closed off the trans cooler portion with the remaining 3/8" hose. If the wall weakens and opens, the coolant will not come out of the radiator and onto the ground. I used tap water to flush out the trans. cooler portion of the radiator.

When I did remove the stock lines from the cooler, some fluid drained out, but not all. I wanted to ensure I could get as much trans. fluid out as possible.

And that is that. Hope that helps.

Thanks for the reply. Yeah that helps out and I'm looking forward to completing this today. If I have the tools I will force the fluid out otherwise I may just leave it for now.

SCRunner12:

I forced out the fluid the poormans' way. Hooking a hose up to it and forcing it out with my lungs and water. Worked fine, but I think I described it well enough.

Glad to know my response helped and good luck.

Well I just got it done. Took about 2 hours, but I can now drive my 4runner without worrying it will be milkshaked. Big thanks to BigFish and pdx650.

Good job, now fix your sig!

Thanks, I just did it.

SCRunner12:

I owe all my knowledge on my B&M install to Zcruiser and Bigfishallday. No need to say thanks to me, but I do appreciate it.

I do work, maintain, and train new soldiers on the Apache helicopter. One thing I've learned is that with massive amounts or rotation comes a lot of vibration. If there are two components that are touching each other that are not supposed to be touching, the vibration with inevitably destroy both components to the point of replacement. This is the reason I suspended my cooler in front (not touching) the A/C condenser or let the cooler rest on the frame below it. That is the only part that was my idea I bring to the plate.

Happy to have another convert in these pages. Good job.

Anyone with that kind of job and responsibility has my respect, regardless.

The stuff I make goes on Navy ships where we have to worry about long-term prop vibration and damping of resonant frequencies. (In fact I've been to Newport News a couple times.)

Thanks Zcruiser. I appreciate the mention. Like wise to you too.

Unbeknownst to me my wife recorded me working on my trans. cooler install for a few seconds from the kitchen window. Here it is:

YouTube - ‪1997 4Runner Transmission cooler‬‏

Haha, that's hilarious! It is neat that your kid likes to help out.

Thought some of you may be interested in this, basically measures 1x15"

FWIW I picked up a new radiator from Autozone for 136.99+tax, and a Jegs 60382 ext trans cooler for $50,... cheap insurance