3rd gen Transmission Cooler Upgrade

Do you still have the external trans cooler in front of the radiator? I understand the 2021 models don't. My 2021TRD Sport does not have it. Got it December 2020.

Again, you're far north in the Lake Superior area which is about 48 degrees North. Here in the desert we're 32 Degrees north just 50-60 miles north of Mexico. Big temp difference from Deciduous Forest as opposed to Desert bioms

 

Towing in the mountains the scangauge AT1 reads up to 219 degrees, normally 194.
Looking for help with adding Hayden 698 transmission cooler to a 2023 SR5 4x4 that does not have a small cooler already, but two radiators, the inside obviously engine coolant and the outside...?
Is the fullsize outside radiator the stock transmission cooler??

Where do I tie the Hayden hoses into? Having trouble with this.
Outside radiator has a nominal 1/4" aluminum pipe on bottom left which connects into an all-aluminum 1/2" pipe back through firewall. No rubber hose anywhere to cut and tie into although there is a capped, threaded fill/test port.
Outside radiator has a nominal 1/2" aluminum pipe on upper right- see pic, which goes back to rubber I can tie into. There is also a capped, threaded fill/test port further back.
If this is the tranny cooling system, do the fill/test/valve ports allow me to tie in? What size/model please.

I also purchased an aluminum bracket that fits the Hayden but no holes line up with the existing frame. Drilling down low will require pulling off lots more trim.
Definately not plug and play, holding off until I get my ducks in a row.

LOWER LEFT, SMALL DIAMETER:



UPPER RIGHT, LARGE DIAMETER:



UPPER RIGHT, INSIDE ENGINE COMPT:


PROPOSED INSTALL LOCATION, ON LEFT:

 

Hi Max8, do not cut into the lines you are referring to. That is the A/C condenser in front of the radiator.

 

You are pointing at the wrong hose altogether. you want the one here circled in blue

 

Thanks for the tips. Still unclear where both inlet and outlet are. Found this picture of a 2014. Anyone have a pic or diagram of 3rd Gen?

 

@Max8, Hoo boy....you sure don't want to disturb the hoses you are pointing at, those are the AC lines. The radiator in front of the engine radiator is the AC condenser.

Look at the pic below: The blue circled line is the hot oil from the transmission. Look straight down below it (NOT the one you are pointing at!), but further down. That is the cooled oil return line back to the transmission.

 

Thank you! Without pulling all the skid plates hard to trace from transmission.

 

You are quite welcome. I am sure of those because I recently added my own oil cooler. Works like a charm.

 

This assumes that the trans fluid temperature is hotter than the radiator fluid. What if the trans fluid is cooler than the antifreeze???

when working on adding the cooler - and feeling the lines - your not climbing a hill with a trailer

 

ATF is designed to run in a range of temps. Toyota opens the thermostat at 195 which is the middle of that range.

The closed thermostat lets the ATF warm quickly to that mid point.

I suppose it could run cold in an arctic environment when the thermostat never opens at all. No cooler needed, ever.

Most of us run in warm temps then additional heat from towing.

 

I agree with JohnDeere630 !! . I kept the line (blue circled) untouched and detached the bottom line. Added new Hayden from that port to the top of the 678. Then reattached the Lower line from the Hayden to that detached original return line. Based on the strength of GPsevenSixx post # 103 below.

I added a

$52 Hayden 678 Universal Rapid-Cool 9.5” x 11” Add-On Transmission Cooler – Not for Direct Replacement of the OE Cooler

Hayden 678 Trans oil Cooler to my 2021 TRD Sport.

I mounted it in front of the Radiator/AC Condenser cooler. It sits about 3” in front of those 2 coolers and about 3” behind the front grill. Big front nose on that truck - lots of room.

It is mounted on the drivers side as high up and to the right as (you face the truck from the front) much as possible , away from the front radar grill gizmo as comfortable, to keep it in the direct ram air inflow as I could. Moved horns to pass side.

I removed the original Bottom return hose from the radiator trans oil cooler and routed some

$20 Hayden 106 Transmission Oil Cooler Hose 3/8-IN Diameter x 4.5-FT Length

Hayden 106 trans hose from that port to the TOP inlet of the Hayden 678. Based on info from Hayden - a post, from Hayden reply:
From GPsevinSixx post # 103
.

Bottom return line from the Hayden External Cooler to original radiator return line connected with 3/8” id brass double barbed joiner. See below pic.. Obviously, kept the original hose connected to the tubing under the car, Didn’t touch that.



Hayden 678 Rapid – Cool cooler unit, with Hayden 106 hoses 3/8”, Fuel injection hose clamps from Harbor Freight. Hillman ¾”w/1/8”t/3’L aluminum stock for my homemade mounting braces. Misc warpy and external tooth lock washers, bolts and nuts with plastic inserts for locking. Black paint. Vise and hammer for persuading purposes.

Hoses covered in places with larger cooler hose for protection when threaded thru radiator wall and behind, where there is possible contact with other hoses. Paid attention to not KINK the hose at any spot. More than 4-5 in radius bend in rubber cooler lines for me. I blew through the whole set up, cooler and extra tubing, before final hook up to test resistance. Hardly anything felt.

PINNED the T-Stat. Added a quart of WS tested for leaks.

Entered in Oil temp Mode via great post of Post #517

https://www.tacomaworld.com/threads...smission-fluid-level-check-diy.547455/page-26

T-Stat PINNED, check bolt loosened-drained to a ‘dribble’. Maybe 10 oz came out. Additional oil of maybe 2/3 qt needed for the extra hoses and cooler. So, Trans fluid level/amount is accurate.

See below results with me in the PU with about 400 lbs of gear last month. T-Stat kept PINNED.

.

Its 95*F outside, Coolant is 190*F going 65 mph, with Trans oil temps are about 160*F. I can add 10*F by occluding the Hayden with a cardboard blocker and will do so for winter.

Done 5,000 miles ago . No troubles. Above results typical. In winter, I will put cardboard in front of about ½ the cooler and it seems to add 10* F.

I live in SE Arizona. We had 110 days of above 100*F this summer of 2024. Up to Grand Canyon, down to Puerto Penasco, Mexico: Some towing about 1500 lbs and some not. You can understand my concern about oil temps

Per post from Dbarffish at post # 449. If running through the radiator, when the trans fluid is cooler than the antifreeze, I’m sure the trans oil does get warmed up some. But look at the operating results shown above with trans oil routed through the Hayden.

Its is nice to have available, the extra cooling potential, when needed.

Looking at the results, I probably could have gotten along with a Hayden 677 considering my driving habits and lifestyle. Because of my cooler mounting location/method, I could keep the same hoses/lengths and just make another mounting brace and swap it out.

 

With a 40% cardboard occlusion in front of the

$52 Hayden 678 Universal Rapid-Cool 9.5” x 11” Add-On Transmission Cooler – Not for Direct Replacement of the OE Cooler

Hayden 678, temps raised about 10*F.
Notice the post above that at #451, the temp was 94*/F99*F but the trans oil temp was 158*F.
So, a 40% occlusion with a 20*F decrease, ( see below), in outside temp gives me almost the same cooling - or warming temp result.

 

I'm looking at adding a cooler to my 2023 V6 SR5. Planning to use the Hayden 698 although a smaller one might be sufficient. Wife is worried I am not using the dealer but the dealer says they won't install non-Toyota stuff (at least that's the way I interpret it - they said they can't install a cooler that isn't Toyota). And I have read others saying it doesn't affect warranty (unless you do something wrong that causes damage of course) so I'm not really worried. They are supposed to get back to me about installing the smaller one that was on the early Gen3s but they said they have to check into that - I'm thinking I want a bigger one anyway. I picked up the needed hose and a 3/8 double barb fitting and the hole in the center seemed awfully small. It's a Tru-Flate 21-467 and the hole is about 0.2". I see on their web site it is intended for connecting air hoses together. hould I be looking for one with a bigger ID?
https://www.truflate.com/all-tru-flate/21-467

 

@JimLS I installed the Hayden 699 on my truck (2023 V6 SR5) and used the kit's stock 3/8" hose and barb just fine. (I did substitute pex clamps on everything). I towed a 3000 lb trailer from Maine to Texas, and the trans temp never went above 195 degrees. (The thermostat doesn't open until 190 degrees, to the best of my knowledge.) Had it been hotter outside, I'd probably have pinned the thermostat. I am very pleased with the cooler's performance.

 

@JohnDeere630 Thanks for that reference point. We have a 3900 lb trailer so probably about 5000 loaded. We are thinking of doing an extended trip to the west coast next year so thinking as long as I am doing a cooler I should just go big. Very little additional cost or effort to do a bigger one and no down side that I know of.

 

Good thinking.
See if you can get those Fuel injection hose clamps from Harbor Freight. I think they, the FI hose clamps, clamp the hoses better.
I like the 678 cooler. It does work, I'll say that ....
recent trip stats with T-Stat pinned. Say 600 lbs - me telescope and camping equipment.

 

Just got a call from what I consider one of the better local dealers I had called about adding a cooler. They said they discussed it with others there including the shop supervisor and just weren't comfortable with the added fluid changing how the solenoids and valving might be affected. Then said that they weren't saying I couldn't do it but would need to go to a shop that was more familiar with the changes. Seems like a strange excuse that they just don't understand how it just adds cooling and not affect shifting or just don't want to do anything not standard Toyota configuration. They did give me the name of a company that makes a bracket for a hayden cooler so I think they did look into it.

 

I installed my kit from Mishimoto and bought some extra 3/8 transmission hose and in line oil filter.

 

Any more pics of your setup? Are you using the bracket the Mishimoto came with? What oil filter are you using?

 

The upper bracket where it bolts up to the horn had to be slightly modified. This Mishimoto kit is for a 2nd gen but work well for 3rd gens too. Been running for a month now, no issues.