ZF 63 ATF check

[jmauld]

I was going to check the ATF fluid tonight and when I started to unscrew the red dipstick tube I could hear pressure bleeding off.

I checked the mercruiser manual and it doesn’t mention anything about this. Is this normal?

I do see that I need to run the engines for two minutes at 1500rpm before checking.

 

[Strecker25]

I was going to check the ATF fluid tonight and when I started to unscrew the red dipstick tube I could hear pressure bleeding off.

I checked the mercruiser manual and it doesn’t mention anything about this. Is this normal?

I do see that I need to run the engines for two minutes at 1500rpm before checking.

normal. The fluid gets hot and after it cools generates a little vacuum in the case. If I check ours after a run it doesn’t hiss but if it sits a while always does. We have the ZF80 but same idea

by the way - check the manual on the proper dipstick reading. Our screw in style is supposed to be checked without screwing it in, I didn’t realize that at first

 

[jmauld]

I just read that as well. Glad I did because I would certainly screw that in to check it.

 

[firecadet613]

Normal. I keep a printout of this with the manuals on the boat so I don't forget.