ATF/Expansion Tank Thermostat

Hey guys, did a complete cooling system overhaul today.

Problem is I broke the ATF Thermostat when I took off the expansion tank. I only saw one or two threads on here talking about this problem, but they were worthless.

I haven't received any lights on the dash, and the car seems to be driving fine. My question is, how long has anyone driven with the ATF thermostat like this? I plan to replace it this week, but I want to know if it can make it up to Williamsburg (~100 miles) and back safely.

I know what the damn thing looks like, but does anyone know how it works. When I took off the expansion tank, the black cap broke off and shot up a spring. Is my tranny getting cooling right now? Or will it overheat?

Thanks in advance.

honestly i'm not sure how it works...but i've seen this happen quite alot. happended to me twice...replaced 'em both at the time i did it so i'm not sure about driving without it. i don't THINK it would hurt anything but i'm not sure.

I did overhauled my cooling system and replaced everything except rad and middle hose (thin hose connected to the exp tank) Dont know If I kept mine. WIll send it to you for free just pay the shipping.

Originally Posted by reynaldo

I did overhauled my cooling system and replaced everything except rad and middle hose (thin hose connected to the exp tank) Dont know If I kept mine. WIll send it to you for free just pay the shipping.

I can't wait to get one shipped, I am going to the dealership on Monday. Thanks for the offer though.

mine is broken too, there are two tabs the the thing is connected too which is holding the spring down right? well the tab on my broke off but when i removed the exp tank. I had it aligned dead center before i shoved the exp tank down on it... i've been driving it since and no issues... its been about 5000 miles give or take...

Originally Posted by hongchu

mine is broken too, there are two tabs the the thing is connected too which is holding the spring down right? well the tab on my broke off but when i removed the exp tank. I had it aligned dead center before i shoved the exp tank down on it... i've been driving it since and no issues... its been about 5000 miles give or take...

next time it opens...it will stay open then

Thanks for the help, got the part at the dealership and put it in today.

hey guys recently change electronic thermostat , was wundering if , to much prestone could ,or air in the system could cause the expantion tank to have crack. in the car the thermstat was operating at perfect temperature, and no sign that is was overheating , when i got back from a test drive , the tank was crack and lost all of my prestone, any of you guys had this happend to you , and know a reason why the tank would of done that , or is it just a bad luck , usually things happends for a reason . let me know

The expansion tank will fail after a certain amount of time/miles. I don't think too much coolant or air in the system will cause it to fail. However, I have heard speculation that a bad cap may lead to a tank crack - the cap may not release pressure when it should. If this is true, then overfilling the cooling system could lead to a crack in the tank because it won't allow the release of excess pressure. But this is purely speculation. The more probable explanation is that, like many other parts, the expansion tank will only perform to specs for a certain amount of time before it cracks under pressure.

I was also in the process of removing my expansion tank and removed with retainer or monting bracket as called by the service book, and of course when pulling these two apart the cap which holds the spring and ATF thermostat broke, not only that but the tabs which hold the cap also broke off, so my question is, the retainer/mounting bracket looks fine, but can I replace the damaged parts inside this inlet tube and is it an easy DIY or if I purchase a new retainer/mounting bracket will it come with these parts already installed . Thanks for any help you can provide.

i have had the same tab broken and spring issue when replacing my tank... i aligned it dead center and push the tank in and everything have been working fine... its be almost a year and no issue. My heat and ac works fine and as good as when i first bought my car. I really don't see any real function in it but what do i know lol... its a spring with a metal thingy that seems to do have very little importance.

got a problem i changed my thermostat and expantion tank but when i start the car up the tank and the upper hose get so hot like its about to explode , i think i bleed the system the right way