Trans Fluid Flush

[Bill MacLeod]

When flushing the fluid today, I pulled the lines from the aux. cooler to determine flow direction. Both hoses displaced a steady stream when the vehicle was started.

So which direction is the flow? From the bottom of the rad cooler, or to the rad cooler? Why did the fluid pump from both lines?

This has me perplexed, so if any tranny experts would care to explain, I would sincerely appreciate it.

Thanks in advance.

Bill

 

[dogfriend]

I noticed this too when I flushed the tranny. I used the "pump one quart out, then pour one quart in" method to flush the tranny when I switched over to Syn ATF.

When you first start the engine, you will get fluid from both lines, however the flow from the return line will diminish until there is barely any coming out. I think that pressure from the trans in the return line blows the return line clear.

On my truck, the line which goes to the top of the radiator is the supply line to the cooler (pumped from the trans to the cooler) and the line on the bottom of the radiator is the return line to the trans.

 

[Bill MacLeod]

Well, I was able to get a quart/litre out of each line before I shut it down. Both lines seemed to be "pumping" at the same flow rate.

Could plug either line and have the other one flow, so this really puzzles me. And, wasting good fluid as the pan was just drained/refilled.

So on the 5R55E trans, flow is into the top of the rad and out the bottom?

Bill

 

[james t]

put it all back together and go drive it for 10 minutes. then crawl under it and feel the lines at the tranny. the one that is hot will be the send line. the one that is warm will be the return. you can then mark and/or trace the lines from there.

 

[Bill MacLeod]

Unfortunately thats not really possible in this weather we are having. Its about 10* F right now. Thanks anways James. Wish I had an infared temp gun.

Anyone have a flow diagram/chart from a shop manual?

Bill

 

[TheRookie]

that technique should work fine in the cold

 

[dogfriend]

I know that I had mine hooked up correctly because the filter would get hot after running for awhile. If you hook it up backwards and you are using the Permacool type filter (oil filter) the check valve in the filter will prevent the flow and it shouldn't get warm.

This is the closest I could find to a diagram. It says that the lower fitting on the trans is the return line.

 

[Bill MacLeod]

Thanks Dodfriend. That is exactly what I need.

Item 3.1 says it all.

Thanks again. I'm going to print this.

Bill M.