Transmission cooler flush

[SOURDOUGHJIM]

Has anyone used Kooler Klean or like product on the trans cooler? Any special fittings or hoses helpful?
'04 V70.
The 2-3 trans upshift is worse if I use the a/c in city driving. Might help if I flush the cooler, I think. I have no issue with engine temp. The temp gauge needle is rock solid in the center, a/c or not.

[dikidera]

The temp gauges on these cars is strongly vertical even up to 120c, so you can be 65-120 and it will show full vertical.

The trans has many things that can happen. Worn out fluid, worn out valve body from clogged solenoids, and of course a clogged filter(partial).

[SOURDOUGHJIM]

I've been doing dump and fill on the transmission along with engine oil changes. Two so far. I have a new B4 servo cover that I haven't installed yet.

[MoVolvos]

Has anyone used Kooler Klean or like product on the trans cooler? Any special fittings or hoses helpful?
'04 V70.
The 2-3 trans upshift is worse if I use the a/c in city driving. Might help if I flush the cooler, I think. I have no issue with engine temp. The temp gauge needle is rock solid in the center, a/c or not.

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If you look at your fluid you should be able to tell whether it's necessary. If temp is affecting the shift the transmission itself is the problem not the cooler.

I have bypassed the radiator's transmission cooler altogether in the 03 Honda Odyssey for probably over 5 years now. Currently at 248K and have never seen temps over 180 all year round. Using a temp gun at the cooler for measurement. The slight bump click when putting into gear at start up is gone and so has the slight slip in the lower gears from time to time. The fluid still looks clean without any smell.

When warmed to operating temp the transfluid will be about the same as the radiator so around 170 - 180. With the auxiliary cooler in front of the radiator and ac condenser it will always see ambient and even on a hot day at 100 so it's quite a difference from 170-180. Heat is the enemy of the transmission.
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Same unit in the 03 Odyssey.

https://www.ebay.com/itm/175200706964?e ... BMhLDgyZBk
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ATF Temp Chart.png (382.56 KiB) Viewed 355 times

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[SOURDOUGHJIM]

BKM, thanks for the info. I did have the auxiliary cooler in the back of my mind but since I drive it very easy and don't do any towing, I figured the factory cooler should be sufficient. Maybe not.

[MoVolvos]

BKM, thanks for the info. I did have the auxiliary cooler in the back of my mind but since I drive it very easy and don't do any towing, I figured the factory cooler should be sufficient. Maybe not.

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Since the problem is heat related I would say get a cooler ASAP in order to potentially prolong the transmission and from further damage. I believe the upper is the return line from the radiator to the transmission. You can either cut that line and insert brass barbed connectors with the same inside diameter of the line and install the cooler in front of the condenser or you can just remove the line at the transmission. If there is a difference in shifts from the reduced heat do a complete flush.

To be honest the reason I bypassed the Honda radiator was my friend had a bent unit delivered for his Odyssey so Amazon provided another. The radiator in my Odyssey from eBay lasted a year or two so i decided to try his bent unit not knowing how long I had with the Odyssey. The radiator's aluminum threads of the trans-cooler stripped easily so after much research decided it was okay to bypass it. Can't believe it has been running great for so long.

The reason for having it at the discharge line of the radiator is during the summer it will be as hot as the coolant so you want the fluid to have the ambient air cool it further before entering the transmission.

The transfluid in the Honda is Havoline Multi-vehicle Synthetic ATF. I did a flush like the video. Around 4 cases used in various make and models without any issues. On another car I just use a gallon of Super Tech fluid first then 2 more gallons of the good stuff so it's a cleaner flush.
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Basic Idea


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[MoVolvos]

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Interesting that the ReMan requires a radiator bypass in order to honor the warranty. The brackets were too much work and not necessary.


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[Oro]

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Interesting that the ReMan requires a radiator bypass in order to honor the warranty. The brackets were too much work and not necessary.

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OP, I agree w/him; I have found the complicated brackets unnecessary and the “zip tie” ones adequate. I’ve put a few trans coolers in different vehicles of mine over the years. One being a 2004 XC70. It’s not hard. Do it downstream of the existing cooler as Movolvos said if you go that route.

Honestly though, cooling capacity is unlikely your main problem (though more in these is a good idea). Have you tried addressing the health of the valve body solenoids? I’ve cured ills with them by using Lubegard AT protectant (the red bottle). Amazon has a very good price on the quart bottle right now. The ester oil base will clean the bores and pistons, and condition the seals. This will improve response and line pressure. As an added bonus, the ester oil will improve heat transfer in the unit and drop temps (just a bit, not a lot - I’ve actually tested this with external temp gauges in a GM transmission). Normally I would start with a more aggressive, very short-term cleaning method and then swap all the fluid out at once. But if you’ve done several drain/fills, you may want to skip that and just let the ester oil work a little more slowly for you.

If you put in a cooler, it’s pretty easy. The hardest part is only getting the bumper cover off; this was when I put the cooler in the XC. From here you have space to insert the cooler and access to the existing cooler lines to splice into them.

[SOURDOUGHJIM]

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Interesting that the ReMan requires a radiator bypass in order to honor the warranty. The brackets were too much work and not necessary.

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OP, I agree w/him; I have found the complicated brackets unnecessary and the “zip tie” ones adequate. I’ve put a few trans coolers in different vehicles of mine over the years. One being a 2004 XC70. It’s not hard. Do it downstream of the existing cooler as Movolvos said if you go that route.

Honestly though, cooling capacity is unlikely your main problem (though more in these is a good idea). Have you tried addressing the health of the valve body solenoids? I’ve cured ills with them by using Lubegard AT protectant (the red bottle). Amazon has a very good price on the quart bottle right now. The ester oil base will clean the bores and pistons, and condition the seals. This will improve response and line pressure. As an added bonus, the ester oil will improve heat transfer in the unit and drop temps (just a bit, not a lot - I’ve actually tested this with external temp gauges in a GM transmission). Normally I would start with a more aggressive, very short-term cleaning method and then swap all the fluid out at once. But if you’ve done several drain/fills, you may want to skip that and just let the ester oil work a little more slowly for you.

If you put in a cooler, it’s pretty easy. The hardest part is only getting the bumper cover off; this was when I put the cooler in the XC. From here you have space to insert the cooler and access to the existing cooler lines to splice into them.
908D5C0B-456E-4EC4-B4D6-1FA28E9E47BC.jpeg

Thank you so much for the input and info. I live in rural America, the previous owner may have had the car in city traffic most of the time. Most of my driving is 55mph or higher with a small amount in city if I do a bit of shopping.

[SOURDOUGHJIM]

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Interesting that the ReMan requires a radiator bypass in order to honor the warranty. The brackets were too much work and not necessary.

.

OP, I agree w/him; I have found the complicated brackets unnecessary and the “zip tie” ones adequate. I’ve put a few trans coolers in different vehicles of mine over the years. One being a 2004 XC70. It’s not hard. Do it downstream of the existing cooler as Movolvos said if you go that route.

Honestly though, cooling capacity is unlikely your main problem (though more in these is a good idea). Have you tried addressing the health of the valve body solenoids? I’ve cured ills with them by using Lubegard AT protectant (the red bottle). Amazon has a very good price on the quart bottle right now. The ester oil base will clean the bores and pistons, and condition the seals. This will improve response and line pressure. As an added bonus, the ester oil will improve heat transfer in the unit and drop temps (just a bit, not a lot - I’ve actually tested this with external temp gauges in a GM transmission). Normally I would start with a more aggressive, very short-term cleaning method and then swap all the fluid out at once. But if you’ve done several drain/fills, you may want to skip that and just let the ester oil work a little more slowly for you.

If you put in a cooler, it’s pretty easy. The hardest part is only getting the bumper cover off; this was when I put the cooler in the XC. From here you have space to insert the cooler and access to the existing cooler lines to splice into them.
908D5C0B-456E-4EC4-B4D6-1FA28E9E47BC.jpeg

I think I found the additive you spoke of. Lubegard 60902