So here is the question. Do these auto transmissions build up a lot of pressure in them? Is that a normal occurence? My friends car, which is a 1998 LX if you go to check the fluid level in the auto tranny after he has been driving it, if you do not watch out it will dang near shoot the dipstick out at you. Mine has never done that. After a fluid change his transmission is also leaking pretty bad. If there is that much pressure building up in the tranny then I assumed that it is pushing fluid passed something. I have a spare auto tranny in my garage from when I had to swap the one in my 98 EX. I saw where there is a breather where the starter bolts up. I will check that out on my friends this weekend when i do some maintenance and make sure it is not clogged or something. If that seems to be alright what else is the culprit?

The transmission has Honda ATF in it. I only use that stuff in these finicky contraptions. Just looking for someone with more experience with these auto trannies to maybe point something out to me that I may have overlooked.

 

It depends on how hot the transmission is, if it seems like it has a lot of pressure as you say, it's probably overheating.

Where is the leak coming from?

 

He is bringing the car to me this weekend for me to check it out further. As of now I am unsure of the source of the leak.

I did not think about the tranny overheating and causing pressure to build up in there.

 

F23? The actual vent may be hidden under the transmission mount, it should be a 90° pressed in fitting. It may or may not have a rubber hose attached to it. When you find it use a wire or pipe cleaner to clear out the fitting.
Be prepared to run and scream like a little girl if a wasp, hornet, or spider has decided to use the vent tube as it's new residence.

 

I told him where the vent was. Last word I got is that he unplugged the hole and it had stopped leaking as bad.

 

Still not leaking as bad as before since the vent was plugged. This is his beater car, but obviously wants it to run alright and not get him stranded. I think what happened is that some maintenance had been done on the car before and that rubber drain hose off of the vent had become pinched in the tranny mount. He unplugged the hose and it has been better as far as the pressure buildup.