ZF 6 speed Flush
 

Hello.

Saw this video the other day flushing the fluid from a Japanese (I guess) auto.

Seems pretty simple if:

1. The transmission can mechanically do this correctly - i.e renew the fluid this way
2. You are very careful
3. You are brave and/or thick skinned

This fellow has the advantage that his auto can be filled from the top and has a dipstick.



Has anybody heard of this being done on a 6HP** auto via the cooling lines?


Is this what commercial shops do somehow?



Cheers

You could do that but the tranny coolant lines are at the bottom of the radiator on the driver's side .

So not really convenient to get to them w/o the car being lifted.

Also the lines use high pressure push-on fittings which make mating to any other lines a bit of a challenge

I plan to partially drain my unit this way next drain to get the dirty fluid out of those lines as well as out of the pan.

Yes - I figured I would need to make an adapter for the lines - but I got a lathe so unless its got an odd geometry I should be OK.

My biggest fear is oil starvation - I would like to come up with a 1:1 input/output system with as little manual intervention as possible.

I wonder what pressure the pump runs at - couldn't find any specs on this.

That sounds like a little over the top for effort but doable I presume.

I can't imagine it would be a high pressure amount, but w/o that # it is a guess.

You can do a static drain that should clear a good amount out right at the cooler lines,

Half the fun is making the tools.

Especially if they work well and get used again - by me or somebody else.

Static drain - do you mean when I empty the pan or just unplug the cooler and let it drain?

Static drain is releasing the lines at the cooler so the fluid can drain by gravity.

If you have time to machine parts that's great.

I sure don't.

So here is the pressure info direct from ZF:

"The pump is making about 17 bar (246.56 psi) but the valve body reduces and regulates it to about 5 bar (72.519 psi) to the clutches"

Thanks for digging that up. I wonder if 5 bar is carried through the rest of the system (cooling, torque converter).

He only states regulation to the clutches of 5 bars.

My guess is that for cooling the fluid is flowing at high pressure.

You can imagine how the torque converter will heat that fluid very quickly.