Thread: Transmission lines to radiator

I have heard/been told there is some type of check valve in the fittings at the transmission where the hard lines plug into tranny and then run up to the radiator.

I am wanting to pull the hard lines all together and just run some SS braided lines up to the radiator. But if there is a check valve at the transmission I dont think Id be able to pull the quick connect fitting there to replace it with a fitting for use with the SS line or just regular rubber lines. Does anyone know if there is a check valve there?

Also, can anyone tell me what side the hard lines are. Are they 1/4", 5/16", or what?

Thanks in advance.

Yep, all quick connects up until Jan 04 production dates had a check ball in the fitting that is the feed to the cooler. This is a anit-drainback checkball and spring so the converter doesnt drain down when the car sits which can cause a delayed take-off as the converter isnt fully charged when you start the car. I just had to 99 GTP trans the past few days, I was shocked when I saw that they both had thread on cooler line fittings BUT one had the checkball and one did not! The 97-mid99 transmissions without the checkball in the feed fitting, the one that points straight down, have this checkball and spring in the channel plate inside the trans. Every channel plate will accomodate this setup, it just isnt used on the models with the ball and spring in the fitting. 04 and up fittings use quick connect lines and NO checkball but they will not fit any earlier cases. The threads were changes so you could not simply swap them. Scotty the easiest thing for you to do is get thread in style case fittings, the feed one WITH the checkball in it and then you can make your own lines that will thread into those fittings and not have to worry about any problems. If you strike out let me know, I get them new from the dealer but you need to make sure the parts guy knows exactly what you are looking for!

Wait, so I can change out the quick connect fittings with some thread-in fittings that will maintain the checkball?

If I understand you correctly, the checkball and spring is only on the feed line (the one pointing straight down) correct? There is not such thing on the return line?

Do you have any part numbers I can take to the dealership? Better yet, do you stock these where I can buy a set from you?

Correct, there is only the checkball on the feed fitting, the one that points straight down and there is nothing in the return fitting-the one that points forward in the car. The fittings have the same thread, I have changed them before. I know I have new quick connect fittings but I will look for the other ones. If you want I can get them for you or at least get you some part numbers but it will be Monday before I can find that out for you.

Thats fine Dave, if I can get them through you Id much rather do that. However, if its a hassle for you, if you can give me the part numbers I'll go to the dealership and order them.

Now I just want to reiterate, I want to get rid of the hard quick connect lines and run SS braided or even just regular clamp on rubber hoses from the tranny to the radiator. I just want to make sure we're on the same page. If I can get some SS braided lines made up, I'll go that route, if not I'll by me whatever size rubber line I need and put on a SS braid sleeve.

You want to either run good braded hose or part steel line, Im not a big fan of running long lengths of the rubber hose. It MUST be transmission cooler line hose if you choose to do so! Good braded hose should be fine also.

Okay, cool. I'll just have some high quality braided lines made up and go from there.

What size transmission cooler line should I use? The lines on this tranny seem a touch larger than any others Ive seen.

Hey Scotty, let me know what you come up with. I am trying to replace my tranny lines as well. I bought the ZZP oversized radiator and I was going to just run that with the stock lines, but I think I will kjust get some modded lines made up and sell the oversized radiator.

Will do bud. Im a ways from getting there as I still got to get the tranny in the car, but Ive been documenting all these extra projects like the braided hose, valve train upgrades and all that good stuff so I can do some how to's, reports and that sorta thing. So I'll have all the details on the braided transmission line and all that it takes to do that successfully.