Diy External Transmission Cooler

[Shankem-Deep]

Since I had the bumper and grill off for my winch install, I figured it would be a good time to add that tranny cooler i've been needing. Picking a tranny cooler is a challenge in itself. I went with a B&M Hi-Tek SuperCooler 70297. It has a built in thermostat that switches the fan on when the transmission fluid reaches 175 deg. I liked the fact that I didn't have to wire any switches or add anything. There are several schools of thought about which way to plumb the external cooler. I decided to go through the radiator 1st and then through the external and back to the transmission. I used brass fittings and 3/8 rubber transmission hose. I didn't modify anything that can't be put back to stock if something goes wrong. I used 1x1 angle iron as mounting brackets. This is a super easy mod that needs to be done if you run larger tires, pull a trailer, or haul heavy loads. Heat is your transmissions enemy. I've had my transmission slip after pulling a trailer loaded down with 4-wheelers and RZR's. I've also had it slip on me after 4-wheeling for awhile in the summer time.

 

[max1008]

Where did you buy the adapter/nipple for the flare fitting?

 

[cliffyp]

Plumbing sections of hardware stores should carry all that. Auto parts stores too, although the selection isn't as good typically.

 

[max1008]

and i take it that the upper transmission line is the trans return line?>

 

[cliffyp]

The upper port on the transmission side is the return line.
I checked the TM to see about the radiator side but couldn't find it. The lower port on the radiator should be the return line. You can just trace the the line from the top port of the trans and double check that it does go to the lower port of the radiator.

 

[Shankem-Deep]

The upper port on the radiator is the return line to the transmission. I used fittings to attach a rubber hose from that upper return port to the external cooler. Then another hose from the external cooler back to the hard return line that goes back to the transmission. If you run the external cooler after the radiator this is how to do it. In this manner you would leave the bottom radiator port (supply) alone.

 

[cliffyp]

The upper port on the radiator is the return line to the transmission

That's why I wanted to check the TM. My memory switched the two.

 

[max1008]

Yep, installed the cooler today and on warm up the lower line got warm quicker, therefore it the feed. The upper is the return.

 

[McLovin]

Hey guys, I know its a old one, but I dont want create a new thread. I hope its OK for you.
Would like to add also an external cooler like 'Shankem-Deep' it did.
But I have some doubts about this connection here:


I could imagine, this is something like a break line (double flare or so?) connection.
If it is so, then it cant work this way, because between fittings A and B should be a 'horizontal' <--> pressure.
Without this pressure, oil will come out between Fitting B and hard line, correct?

I think, it can work only, when Fiting B is totally rusted to the hard line.

What do you think?
Are there maybe better solutions?

 

[cruzer747]

If that coupler is a flare coupler than it would work fine. As pictured it goes from line>flare fitting>flare female coupler> flare to fpt adapter>mpt to barbed fitting.

IMHO this is ok IF you specifically want to return to stock for whatever reason. If it is to be permanent then it should be done with the fewest fittings (points of failure and cost) possible. Also they do have a more graceful adapter to go from flare to barb in one step. That is if you want to use rubber hose which is a far second compared to SS tubing.

My solution was a cooler that had AN fittings. Got ss line (5/16 od...same as stock) and a pair of an-5/16 compression fittings to attach to cooler. bent the pipe to snake into by the radiator outlet. have the feed from upper radiator going to cooler and connected with a flare connection. Had to use a torch to soften the ss up enough to let the flare tool roll it, re-used stock nut. Had a leak at the radiator which was solved with a $1 flare washer. Then leaving the cooler it goes straight in to a compression union and I had to cut the stock line. I cut it right behind the original flare so if I wanted I could go back to stock just by reflaring.

Looks pro, bends were done by hand/vise with the aid of an alternator pulley. Also the ss adds a touch more cooling

Pics on my thread if you want to see. Most of the final tranny cooler pipe routing Also put the cooler switch at the pan as it will not see the right temp to turn on/off up front. Be aware also if the adapter for the temp switch is used, the little threaded hole to mount it goes to fluid so id needs to be screwed on with sealant. stupid design.

 

[McLovin]

...Also they do have a more graceful adapter to go from flare to barb in one step...

Ya, I have searched today for such fittings, but not easy to find.

Will this one work for me (SAE 45 Inverted Flare Female, 3/8" x 1/2-20) for the hardline side?

Tompkins 4305-06-05 Push-On Hose Barb Fitting, Barb to SAE 45* Inverted Flare Female, 3/8" x 1/2-20", Brass: Amazon.com: Industrial & Scientific

Tompkins 4305-06-05 Push-On Hose Barb Fitting, Barb to SAE 45* Inverted Flare Female, 3/8" x 1/2-20", Brass: Amazon.com: Industrial & Scientific

www.amazon.com

This here could work for the radiator side, right (unfortunately out of stock)?

Tompkins 4303-06-05 Push-On Hose Barb Fitting, Barb to SAE 45 Inverted Flare Male, 3/8" x 1/2-20", Brass: Amazon.com: Industrial & Scientific

Tompkins 4303-06-05 Push-On Hose Barb Fitting, Barb to SAE 45 Inverted Flare Male, 3/8" x 1/2-20", Brass: Amazon.com: Industrial & Scientific

www.amazon.com

or

Brennan Industries 2115-06-05-B Brass Straight Tube Fitting, 3/8" Hose x 1/2"-20 Male Inverted Flare Swivel Straight Brass: Amazon.com: Industrial & Scientific

Brennan Industries 2115-06-05-B Brass Straight Tube Fitting, 3/8" Hose x 1/2"-20 Male Inverted Flare Swivel Straight Brass: Amazon.com: Industrial & Scientific

www.amazon.com

...Pics on my thread if you want to see. Most of the final tranny cooler pipe routing ...

Really nice write up, thank you for sharing

Here some pics of stuff, what I have here (Translife Flex-a-lite 4126 - 10"x20"x3/4" with 3/8" barb fittings):

 

[cruzer747]

All of your fittings look like they will do the job. Stock thread is 45' 1/2x20 so you are fine there. Make sure to get hose rated for tranny fluid.

I would say that as a survivor of many a leaking rubber transmission line (sooner or later it will happen) dooing it hardline is a bigger up front investment but it is worth the extra time. I think you mentioned you have the brush guard off. not something you will want to do for a leak down the road! Anywho, good luck and may your tranny live a long life!

 

[McLovin]

All of your fittings look like they will do the job. Stock thread is 45' 1/2x20 so you are fine there.

Thank you for your confirmation

Make sure to get hose rated for tranny fluid.

I have ordered a special hose for hot ATF oils (sorry, its in german):

MMT-Industry Products - Ölschlauch-Ø8x14mm

www.daimex.de

But I think the bottleneck would be not the hose, rather the clamps, right?

would say that as a survivor of many a leaking rubber transmission line (sooner or later it will happen) dooing it hardline is a bigger up front investment but it is worth the extra time...

Now, you make me bit nervous.
Are such burb / hose connections really so 'error-prone'?

 

[cruzer747]

Now, you make me bit nervous.
Are such burb / hose connections really so 'error-prone'?

I hope someone else can weigh in here.

In my experience it is the heat of tranny fluid and the heating cooling cycles of the connections and then probably using whatever cheapest ATF rated hose available at the local stores (they do make different flavors and grades). I put up with a bit on a low mileage run around town hot rod, but for something that you need to drive out into the woods on 500 mile trips I do not want to even consider a dry/leaky/loose hose as a potential to spoil my camping trip if it happened to allout fail. I dont think I would worry so much but the brush guard and grill take me over an hour each way and that is having access to my tools at home! (the dual receivers in the front have a welded plate that make the inner 4 bolts a major PITA!

I am sure any ATF hose is fine for 5+ years with no leaks properly done, I would just rather pay it forward knowing that the ss will outlive me. Saying that I think I should have added some stress reducing attachments to cut down the vibration at the front of the grille.... hrmmm. If mine ever leak or break I will revisit this thread!