How to drain/flush a C4?

[Goose]

Hello everyone,

How do you all go about draining and doing a fluid flush on your C4 transmissions? My car has no torque converter drain, and I have heard taking the pan off only removes a couple of the quarts of oil.

I was able to get some oil out by putting a hand pump in the dip stick, but this isn't ideal considering I want to do a total fluid flush.

I was also thinking about running the car with the transmission coolant line off(so transmission fluid spills out), and then filling the transmission with coolant through the dipstick as it flows out the coolant line to the radiator. Is this possible?

Thanks

 

[will e]

My limited understanding is the best way to flush it is to pull the pan and attach a source to where the fluid is drawn into the transmission. I believe the filter is removed to do this. It requires a bit of special equipment.

Another option is to put a drain plug in the pan the first time you do a 'simple' fluid change. Drive is a bit and change the fluid again. Repeat a few times. It still won't get all of the old fluid out of the mixture but it will greatly reduce it.

 

[mustang7173]

Goose,

Since the transmission lines are connected to the cooler tank on the radiator, One can disconnect the return line, adapt a line from the output line into a bucket or bottle, crank the car, let it idle with engine at running temperature and let it pump out the fluid until it starts to show no flow or starts spitting out. Once this is done, reattach and remove the transmission pan. I have done this several times in the past.

I was looking a transmission with the side drain plug, I could not find one. If you can, you could get a aluminum pan that a little deeper that would help remove the heat better, have more fluid, and comes with a plug.

mustang7173