Pinkish trans fluid after installing radiator

Question

2004 Toyota Camry XLE 2.4 l 4 cylinder 2az FE engine 142,000 MI

I ended up getting a radiator replaced with an aftermarket carquest brand with transmission cooler inside radiator. The shop put the wrong radiator in my car and I drove it to Miles home and parked it for the night. The next morning I went outside and seen a leak at the bottom of the radiator on the splash shield. I called the shop and they had me bring it in immediately and said there were two models for that year car and the auto parts store sent them the wrong model. So they put in the correct model and I have no leaks. This is back in 2024 around a year ago but since then I've noticed the transmission fluid I can't get a correct reading and the color of the fluid is a pinkish color. The garage also used fram 301 all makes all model antifreeze in my Toyota which I just realized after I looked at the invoice number up. When driving the car it does not overheat and I can get up to third gear but the car stays between first and second gear and second gear on the highway but if I'm going up or down hills in rural areas there is a delay of shift in the automatic transmission for a few seconds. I have to press on the gas to get it back into gear again. I checked the fram 301 and it said that the color is yellow. I know Toyota uses the super long life coolant which is a pink color and the transmission fluid is red just like the power steering fluid. Also before I drive the car and check the transmission fluid the dipstick shows fluid between the cold and hot mark. Then when I start the car for the day and drive around for a little bit after the fluid has went into the transmission the reading is at the cold level. When the temperature warms up above freezing I drive the car about a half hour and check the transmission fluid on level ground and it almost reaches the hot mark. I realize now I should have went with a denso OEM radiator with transmission cooler instead of the aftermarket carquest with transmission cooler. Could water be leaking into the transmission somehow to lighten the color from red to Pink? What test can I do to find out what's going on? I could take it to a reputable garage not like the last one but I don't want them trying to sell me the kitchen sink either. I thought about doing a drain and fill with the ATF fluid and see how that works. There are no external leaks near the transmission pan and nothing dripping on the ground. But I do see what looks like a wet spot in the back of the transmission near the firewall on the bottom but no leak. It also seems like the transmission fluid itself does not get hot the way it used to. What would you guys do in this situation?

Chuck Tobias · Accepted Answer

If you had coolant mixing into the transmission fluid your transmission is shot.

Chuck Tobias · Answer

[quote data-userid="180219882" data-postid="327970"] I'm going to take out some transmission fluid and boil it to see if there are bubbles to know if there's water in it. [/quote] It's not just water, it's coolant. (You should have about a 50/50 mix of water and antifreeze.) There's not much else that's going to turn the fluid pink. In extreme cases it would look like a strawberry milkshake. [quote data-userid="180219882" data-postid="327970"] I'm wondering how did this happen [/quote] Typically that would happen when a trans cooler built into the radiator is leaking, allowing the coolant and transmission fluid to mix. [quote data-userid="180219882" data-postid="327970"] Can I hold them liable for this damage ? [/quote] You would have to ask a lawyer. Probably difficult to prove, particularly since you're dealing with a 21-year-old car. [quote data-userid="180219882" data-postid="327970"] couldn't I flush the coolant system if the radiator is not shot and do multiple drain and fills on the transmission to clean it out? [/quote] That might help temporarily but damage to bands and clutches has already been done. Maybe you'll get lucky.