ATF drain question

[osprey92]

I am looking to change the transmission fluid but want to do several flushes with Valvoline Maxlife Multi prior to dropping the pan. Has anyone drained the transmission fluid from the top fill hole? Are there any restrictions preventing this from working with a hand/vacuum pump on an 8HP70 transmission?

 

[PoMansRam]

Your ZF8 has a drain plug on the plastic pan, although it's partially blocked by an exhaust cross-over pipe on most models.

I've never heard of anyone trying to pump fluid out from the side mounted fill port. Not sure if it's a clear shot in there and you'd have to hook the hose downward and hope it goes where you want it.

You will get a quart or so out just by removing the fill plug with the engine off. Jack up the drivers side to get more out that way if you want, then idle the engine and refill till it starts dribbling back out.

There's lots of threads on this site on pan/fluid changes and ATF level checking on the 8spds.

 

[MRFREEZE57]

Install a PPE pan. The drain plug is easily accessible and has a replaceable filter. I installed one on my truck and did 3 drain and fills.

 

[osprey92]

Install a PPE pan. The drain plug is easily accessible and has a replaceable filter. I installed one on my truck and did 3 drain and fills.

Doing that when I drop the pan.

 

[osprey92]

I just saw a pic of the tranny with pan off. I'm fairly certain there is no way to get a drain line to the bottom of the pan.

 

[joesstripclub]

I've drained 2 or 3 times on my cheapo ebay pan with no issues, I'm sure you could drain the OEM or PPE pan more than once as well. The factory will get some fluid on the exhaust but its easy enough to wipe off. Cut down the proper size allen key (10mm IIRC) and its pretty easy to drain.

 

[FORGEDRAM]

Did you re use the transmission bolts or did you get new ones?

Install a PPE pan. The drain plug is easily accessible and has a replaceable filter. I installed one on my truck and did 3 drain and fills.

 

[Jane S]

I am looking to change the transmission fluid but want to do several flushes with Valvoline Maxlife Multi prior to dropping the pan. Has anyone drained the transmission fluid from the top fill hole? Are there any restrictions preventing this from working with a hand/vacuum pump on an 8HP70 transmission?

You can buy a 12V pump and do it. It is very easy.

 

[EdGs]

I don't believe you'd be able to get a hose in there.

If you're already going to install a PPE pan, why bother trying to pump it out? Use a cut-down 10mm hex key to loosen the drain plug, and drain it. Or, loosen the pan bolts and let it drip.

Some brakleen on a rag does wonders for cleanup.

Break the fill plug loose before you drain the fluid. You'll be surprised how tight they are. I had to use a cheater to break mine loose.

 

[Wild one]

I am looking to change the transmission fluid but want to do several flushes with Valvoline Maxlife Multi prior to dropping the pan. Has anyone drained the transmission fluid from the top fill hole? Are there any restrictions preventing this from working with a hand/vacuum pump on an 8HP70 transmission?

Pull the lines at the cooler and use a syphon style wash gun stuck in a bottle of new fluid to blow the old fluid out of the cooler in the top of the A/C condensor,and replace it with fresh fluid. Dial back the regulator on your compressor to about 30 psi. That should get rid of the majority of old fluid in the cooler,throw a new pan/filter on and fill it up according to the instructions,drive it till it gets hot,then do the check procedure once more after the transmission has cooled back down (next morning etc.),and call it good.