Well I got the heat exchanger lines off today so I could see what size the fittings are. I found out that the rear fitting is a 1/2"NPT and the front is a 3/8NPT. I also found out that the front fitting has a check vavle in it. Has anyone removed this? Will it cause any problems getting rid of the check valve? Any help would be appreciated.

 

Your supposed to remove it if you put in a shift kit. Dont want it to plug up and over heat

I couldnt find a check valve on my truck. It was supposed to be on the line going into the radiator air cooler.

Was yours not visible inside the line in the front of the intercooler?

I wonder if I have one hidden in there that I could not find.

 

Check valve got 86'd in '98, I believe.

 

The check valve is in the fitting that goes into the heat exchanger. It is on the hot line from the tranny to the heat exchanger. I didn't think the 99's had one either until I found it.

 

The in line "hot" is the rear line. I replaced that with ported line. No check valve in that line

Was your check valve a " hidden" valve in the line that you would not notice till you took the line off?

 

The check valve is right at the end of the line going into the radiator.
It is there to help the trans heat up and not stay too cool.
In my opinion a bad idea. Tranmissions work better cooler, than hotter.....
I had one on my gasser and it was always the problem when the trans would expire.
I removed it and ran a straight cooler without going into the radiator and all was well.

Find the valve and remove it!!!!!

 

Yes it is hidden, It looks just like the other fitting in the heat exchanger except it has a spring and plate in it. It is a one way check valve. Heck I didn't know it was a check vavle until I pulled it off and got a face full of fluid. Then I had to look at it and figure out why. I have heard it is there to keep the convertor full of fluid. I am just curious if it would hurt anything to leave it off.

 

The shift kit I installed has a anti drain back up-grade, and instructions said remove the valve , its not needed and you wont have to worry about it getting stuck.

 

The check valve in mine was above the hot line at the heat exchanger. The long line came off, then there was a short braided rubber line no longer than 6" attached to the heat exchanger. It was a pain to get that one off. A pair of needle nose pliers is all it took to pull the ball and clip out.

 

I replaced mine with a 95 line, ported for temp gauge. Had the ball/spring in it.... had to drill it out.
Hurts nothing, and improves flow... but tranny fluid may drain out overnight. Just allow time (30-60 sec) for refill on first start up to prevent servo wear.

RJ

 

its there so the torque converter stays primed, if it is removed u might have to let the truck idle a few seconds in neutral before it will shift into D.

 

I just had a Smr kit installed,,the shop said they could not find the check valve,are you talking about the heat exchanger located on the pass side under the manifold?,,I guess I need to find it and remove it soon

 

It is connected to the heat exchanger.

 

I could not find a check valve on my truck either. I didnt have one. Or dealer per preivious owner removed it when tranny was replaced under warrenty.

I put in a SMR shift kit also.

Remove the check valve if you have one. Any upgraded trans or shift kit fixes the drain back issue.

 

There is a hard line- straight about 5-6 inches long. it is between the trans line and the heat exchanger. If I remember, it is to the rear of the exvhanger. i think they started putting them on the 2000 model year.