Is it necessary to warm up the transmission fluid before doing a drain, or is it recommended for some reason? I'm not terribly concerned with getting every last drop out as a good portion will remain inside the transmission anyways.
DO NOT heat it up as it expands and unless the fluid going in is at the exact same temperature and therefore the exact same volume, you'll get false readings. When cold, both fluids are at the same temperature so you can do so many quarts out and an equal amount of quarts in.Is it necessary to warm up the transmission fluid before doing a drain, or is it recommended for some reason? I'm not terribly concerned with getting every last drop out as a good portion will remain inside the transmission anyways.
Is it necessary to warm up the transmission fluid before doing a drain, or is it recommended for some reason? I'm not terribly concerned with getting every last drop out as a good portion will remain inside the transmission anyways.
I don't think with an automatic transmission it will matter too much. Reason being once you start the car and move it the fluid is circulating and what's not caught up in the filter and magnet in the pan is suspended in the fluid. There's still a large percent of fluid in the torque converter which is not getting drained with dropping the pan. So to do a thorough job, after the filter and pan have been reinstalled and the transmission topped up, driven and checked for leaks, a line off fluid exchange should get most of the remaining fluid and contaminants out.Oil solubility goes up as it gets warmer. It can hold and thus drain more contaminants when warm.
So then, do you recommend warm or hot drain? Thanks.Oil solubility goes up as it gets warmer. It can hold and thus drain more contaminants when warm.
So then, do you recommend warm or hot drain? Thanks.
I don't think with an automatic transmission it will matter too much. Reason being once you start the car and move it the fluid is circulating and what's not caught up in the filter and magnet in the pan is suspended in the fluid. There's still a large percent of fluid in the torque converter which is not getting drained with dropping the pan. So to do a thorough job, after the filter and pan have been reinstalled and the transmission topped up, driven and checked for leaks, a line off fluid exchange should get most of the remaining fluid and contaminants out.
OTOH changing engine oil warm is a good idea.
I've always been told warm for a manual box and cold with an auto. In the auto the level can change quite a bit depending on the temperature of the fluid
That's a PITA on a transmission with no dipstick. When I do a DAF....I'm only going through the check procedure once. So a cold fluid drain it is for me.doesn't matter, fill to cold level, go for a drive and recheck/add what's missing.