C4 flush

[bbyrnes1]

Hey guys,

Automatic trannys are a mysterious mystery to me as to how they work, I just like it when they do.

I'm going to fill my C4 up with Amsoil. I have the tranny drained, but I'm sure there's still some fluid left in the converter. I'm planning on doing the "gentle flush" as I've heard people call it and unhook the feed line to the cooler and let it pump out the old fluid as I fill it up with the Amsoil.

The only problem is the fluid in it is new, so it'll be hard for me to tell if it's pumping out the old stuff or the Amsoil.

What will it pump out first: the fluid in the converter or the new fluid I'm filling it up with through the dipstick tube? I appreciate the help, and if anybody wants to give me a "Transmissions for Dummies" lesson that'd be great too.

[Donnie]

The first fluid to reach the cooler,comes from the converter, does your converter have a drain plug? but the fluid that you add will soon be picked up by the pump...& mixed....Hope that answers your question..............If you want my advice ===SAVE YOUR MONEY ! ! >>>Donnie
Get a case of BRAND name type F & go>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

[bbyrnes1]

Just a conceptual question; how does the pump fill the converter? The nose of the converter is filled with the stator support and input shaft. It doesn't seem like there's much room for fluid to be circulated in and out of it.

[Donnie]

It may seem like it to you because you cannot see the area around the stator support because it is out of view when the converter is installed in the trans.
If you were to have a pump apart & just holding the stator support in your hand, you could install it into the conv & see the space...
Or just use a caliper & measure it.............it will come to you ................Donnie

[bbyrnes1]

Donnie,
Could you explain how the fluid circutry works in these, such as the fluid gets sucked from the pan into the pump, then the pump to....

I'd like to know more about this tranny, and transmissions in general, but don't want to take it out of the truck and take it apart to do so.

Thanks a lot.

[Donnie]

Hi, fluid dynamics 101 basic: this is a short post on the fluid route's in some Ford transmissions..Chry uses a hollow input shaft as do MANY others...The fluid leaves the pan as it it sucked up by the pump, it leaves the pump & goes into the valve body where it is first directed to the pressure regulator, this valve controls pressure for the main part, but is influenced by other circuits which I'll leave out for now..this is BASIC 101 remember? it is divided in the valve body where some fluid goes to fill the converter, some fluid is directed to the selector valve which will send it on to the section of the valve body that you have chosen, E.G. In the D position it will fill the foreward clutch drum & apply that clutch pack & some fluid will be directed to the gov & to the mod. valve & to the 1/2 shift circuit..in the valve body.. after the vehicle is driven fast enough the gov pressure will over come throttle pressure (this is controlled by the mod. valve) which is monitoring your foot/throttle opening..& then a 1/2 shift will occur.<>.when it is time for 2nd gear, fluid is then sent to the 2nd gear band along with the foreward clutch, & the band will apply, & as speed is gained & it is time for 3rd gear, the band will release & the 3rd/rev clutch will apply..the foreward clutch stays applied in all foreward positions.........This is a VERY BASIC explanation of how things work.. To go into more detail, will only confuse you..The valve body has MANY more functions to perform during the above explanation, but this is sort of what I think you were asking.
The converter fluid travels along thru the stator, both on the inside & outside to enter & exit the converter. If you notice inside the stator there are bushings that support the input shaft. these are lubed in the process by conv oel.
the converter oel after being cooled returns to the rear of the trans & acts as lube oel to keep the back end (planets) lubed..
I have only touched on theory here, but if you want more, just ask..............Donnie