4R100 Fluid Change Problem

[Hank]

My son and fought a real battle this afternoon. We did a tranny fluid flush. I have read everything published concerning this procedure and just knew it would be a snap. Well....there was a problem.

The return line was directed to a container with vinyl tubing while we filled, ran 'til we saw air, filled, etc. What we didn't expect was high pressure fluid coming out of the return line connection on the rear of the tranny. We had fluid running down the drive! The only way we were able to complete the flush was for my son to push a rag in the opening on the side of the tranny while he waited for the air bubbles to show in the tubing from the return line.

What was happening? Why haven't I read about anyone else having this problem? Is there a problem in the tranny causing this? Did the chip I have somehow cause it?

We're done now, but any help in answering my questions will be greatly appreciated.

Thanks in advance!

[Hank]

Hoping someone sees this this morning. It was late when I posted last night.

[badazzstroker]

just make it easy on yourself and drop the pan change the filter and replace the amount that you took out,it is the best way to do it a flush donsnt get rid of contaminants or change the filter.

[sirnunya]

"TESTING:

* Bring the transmission up to temperature. It needs to be at least 100 degrees for this test.
* Turn the truck off.
* Remove the rear line from the transmission and place it into a bucket or similar container so that you can measure volume of your flow.
* Have someone turn the truck on.
* At idle (in park), you should measure 32 ounces of fluid in your bucket - in 15 seconds or less. This is an absolute minimum number. A properly working transmission will flow that amount in about 10 seconds or less. You should not see ANY fluid pumping out of the rear transmission port.

TEST RESULTS:

1. If you have the proper amount of flow, your transmission pump and coolers are working fine. SO, if you are running hot and have the proper flow (with no fluid coming out of the rear transmission port), you most likely have a mechanical problem causing high heat. This could be torque converter slippage or one of many other internal problems. You may have to see a professional at this point to help diagnose the problem.
2. If you do not have proper flow, OR you have fluid coming out of the transmission rear port, you either have a cooler blockage, OR a faulty cooler bypass valve. Here's how to tell.

* Trace the forward transmission line to the front of the truck.
* Remove the line from the 1st place it enters a cooler or the radiator (if so equipped).
* Now, do the same flow test checking flow at this point.
* There are two outcomes.

1. The first is that you now have enough fluid flow- this means your cooler /coolers are partially blocked. To determine which cooler is plugged you would perform the same flow test through one cooler at a time.
2. The second outcome will be that you don't have enough flow even with all coolers disconnected. This means you have an internal pump problem.

IMPORTANT! The outcome of this test assumes that you have NO fluid exiting the rear port of the transmission. If you perform a flow test with the coolers disconnected and you get fluid from the rear port on the transmission, your cooler bypass valve is bad."



got this off of dieselsite....kinda sounds like what you're describing. maybe the trans was not up to temp and the bypass was bypassing??

[Hank]

Good info!

No the truck probably was not 100 degrees. None of the instructions I had downloaded mentioned getting it warm. It wasn't ambient, but it wasn't 100 degrees either. Oh well....guess I'll ask my tranny man. He'll think it is funny that I was trying to cut him out and had a problem!

[greenie]

Originally Posted by sirnunya

"TESTING:

* Bring the transmission up to temperature. It needs to be at least 100 degrees for this test.
* Turn the truck off.
* Remove the rear line from the transmission and place it into a bucket or similar container so that you can measure volume of your flow.
* Have someone turn the truck on.
* At idle (in park), you should measure 32 ounces of fluid in your bucket - in 15 seconds or less. This is an absolute minimum number. A properly working transmission will flow that amount in about 10 seconds or less. You should not see ANY fluid pumping out of the rear transmission port.

TEST RESULTS:

1. If you have the proper amount of flow, your transmission pump and coolers are working fine. SO, if you are running hot and have the proper flow (with no fluid coming out of the rear transmission port), you most likely have a mechanical problem causing high heat. This could be torque converter slippage or one of many other internal problems. You may have to see a professional at this point to help diagnose the problem.
2. If you do not have proper flow, OR you have fluid coming out of the transmission rear port, you either have a cooler blockage, OR a faulty cooler bypass valve. Here's how to tell.

* Trace the forward transmission line to the front of the truck.
* Remove the line from the 1st place it enters a cooler or the radiator (if so equipped).
* Now, do the same flow test checking flow at this point.
* There are two outcomes.

1. The first is that you now have enough fluid flow- this means your cooler /coolers are partially blocked. To determine which cooler is plugged you would perform the same flow test through one cooler at a time.
2. The second outcome will be that you don't have enough flow even with all coolers disconnected. This means you have an internal pump problem.

IMPORTANT! The outcome of this test assumes that you have NO fluid exiting the rear port of the transmission. If you perform a flow test with the coolers disconnected and you get fluid from the rear port on the transmission, your cooler bypass valve is bad."



got this off of dieselsite....kinda sounds like what you're describing. maybe the trans was not up to temp and the bypass was bypassing??

Cool stuff,thanks

[ru sliding]

I was having a high heat problem with my tranny today while at the dealer. Thought I was having a power issue... the tech had the dealers tranny guy take it for a ride. They got back and the od light was blinking....hooked it up and had a hard code for tranny over heat with a temp of 272.

Checked the cooler and lines, line into the aftermarket cooler was hot and cooler along with return line cold. Thought maybe the cooler was clogged so disconected both lines to see if we had flow and we were getting flow from both lines, totally baffled the dealer tranny guy. We blew air through the cooler and it was open, no sludge came out. I had them just bypass the cooler alltoget for now.

My truck did have some blue anodized fitting leading up to the cooler looked like some sorta bypass valve. I had both the pressure and return hoses running through it.

Any thoughts?

[Hank]

Originally Posted by ru sliding

I was having a high heat problem with my tranny today while at the dealer. Thought I was having a power issue... the tech had the dealers tranny guy take it for a ride. They got back and the od light was blinking....hooked it up and had a hard code for tranny over heat with a temp of 272.

Checked the cooler and lines, line into the aftermarket cooler was hot and cooler along with return line cold. Thought maybe the cooler was clogged so disconected both lines to see if we had flow and we were getting flow from both lines, totally baffled the dealer tranny guy. We blew air through the cooler and it was open, no sludge came out. I had them just bypass the cooler alltoget for now.

My truck did have some blue anodized fitting leading up to the cooler looked like some sorta bypass valve. I had both the pressure and return hoses running through it.

Any thoughts?

What year is your truck? 4R100 tranny?

[ru sliding]

it's a 2001 f350 4x4 extended cab.

I just ordered the cooler bypass valve online for it. I think I'll put the new valve on, change the fluid and filter and add some lucas to it and hope for the best.

Normal driving the truck seems to perform and shif well, I hope to just order a new rebuilt bullet proof trans next month and drop it in. I plan on hauling some big trailers with it next year, 4 horse with living quarters and a 20,000# log loading trailer.

[chappy]

I would suggest checking the bypass valve.If your not gonna keep the tranny much longer,then don't worry about the fluid but if your gonna run it much longer,you are gonna want to change that tranny fluid cause its toast now.