Greguw

Hi guys

I was doing some reading on here about the trans oil lines ... Mine were a mess ... they were not secured any where ... just floating and rubbing .

I isolated the lines and remount them so they could not rub ... them fittings look kind of funky ... no leaks .

I followed the line's ... looks like the front line feeds into the heat exchanger then comes back a cross then runs up to the cooler and back out to the rear of the trans .
Dose any one know what the fluid pressure after the exchanger is ... I can't figure out why dodge use's clamps on the hose's going in and out of the cooler .
Mine did not even have fuel injection clamps ... I put to injection clamps on mine ... I'm not replacing the lines yet ... they seem to be in pretty good condition .
But I would like to add to the return line a mag filter ... I have used them on a few of my trucks in the past ... I was just wondering the operating pressure and if the rear fitting on the trans was the return line ..

Thanks Guys

Greg

infidel

The return fluid from the cooler dumps into the oil pan where there is zero pressure.
The only pressure in the cooling system is due to resistance to flow in the lines and front cooler. My guess is the highest pressure is less than 20 psi at the start of the output line. Past the front cooler my guess is that the pressure is close to zero.

redramnc

There is some pressure in the lines so that the anti-backflow checkvalve can be overcome. This may be some of the reason the clip that fails most often is on the out line. The real issue with the push-in line connections is the heat generated by the trans and carried by the fluid to the cooler can cause the nylon? retaining clips to soften, fail, and leak, sometimes massively with no warning. The screw-in line fix ain't cheap at $300 and is an aggravation to get done but then dumping all your trans fluid going down the road is much more expensive and much more of an aggravation.

No real good solution except to change the lines to something other than the original setup.

Greguw

Thanks for the info ... Right now I'm way over buget on this new project ... The line look like they will be fine til the summer .
I will replace them ...Do you know what size pipe thread is ...looks like there is one in the trans on the return side and looks like theres on coming out of the heat exchange tank .
I will do some reseach on if I'll do them in all steel or I have access to a company that makes stainless steel braided teflon lines that have 1/4 or 3/8 npt on the ends ...I think that would be a good choice ...temp rated for allmost 500 degree's and 250psi .

Thanks for the info .

Greg

TIMMY22

be very carefull greguw, they are not your standard pipe tapered pipe thread (NPT). Two common pipe thread sizes exist, the tapered National Pipe Thread (NPT) and the straight National Standard Free-Fitting Straight Mechanical Pipe Thread (NPSM).

If you thread a NPT into a NPSM hole in an aluminum casting (tranny) you will either cut a taper or crack the casting.

Dodge desingned this to screw you if you don't buy the fittings from them!



I've been all through this, your best bet if you want to avoid dodge is to get hydralic lines made with the NPT ends on each end then buy say a 3/8" NPT to 3/8" NPSM coupling for the ends.

on my truck it was like 3/8" into the tranny and 1/2" into the cooler.

Greguw

Is are the threads straight JIC type ...They are a straight and you can get them in any size ...They are commonlly used in the hydraulic fittings .

Thanks for the info ... Like I said everything is nice and dry for now .

Greg

TIMMY22

JIC fittings have a 37 degree flare on the end. They seal at the flare, not on the threads. Pipe type fittings seal at the threads. So, no they will not work.

TIMMY22

http://www.discounthydraulichose.com...og%20ST509.pdf

starts on pg. 13

http://www.discounthydraulichose.com/

Greguw

Hi guys

Don't ever order from that link ...I'm like 10mins from these guys ... I went there for oil lines ... I told them my exact need and they made me these hose's that leaked and one of there fittings cracked .
They use cheap brass fittings and if you look at there areo steel fittings the threads are chiped ...
Stay far away from Discount Hydraulic link if you want quality .

Later guys

Greg

northslope

I changed mine at the exchanger, as I recall they were both
3/8" npt

Greguw

Hi Guys
I am looking at the fittings on the transmission ...my fittings on my trans look like there 1/4 NPSM ... not 3/8 ...the heat exchange tank looks like they are 3/8 ...
Were there transmissions with smaller feed holes ...?

Thanks
Greg

TIMMY22

No, That sounds right. One is larger than the other. When you clamp the tubes at the oil pan, take some short pieces of 5/8 heater hose, slit them down one side and sleeve the tubes where the clamp goes. This will prevent vibration chaffing the tubes. A small ammount of teflon tape on those threads will help too.

Greguw

I am ordering stainless steel braided teflon hose's ...the lines are 13/64 ... just a hair under 1/2 ID the lines come with female 37 degree JIC .

Then I will track down the JIC to straight 1/4 thread ... I am also going to install a inline screw on trans filter ...If you other guys are intrested .

You can hit Grainger for a Hydraulic oil filer with a 20 micron filter its a parker brand , but the housing is the same and you can also order the little gauge ...its cross over to baldwin is a BT839 for the filter ...same trans filter .

Later Guys

Greg

Greguw

Hi Guys
Any one know if 3/8 ID Hydraulic lines will be large enough for the trany to work properly ... I was have a hard time getting everything to work with 13/32 hose ... but I can do every thing in 3/8 ID .
Thanks Guys

Greg

John Faughn

I thought I'ld tag on here since its close to what I'm diong, I've got a leaking hose [ about 8-10 " long ] under the exhaust manifold { heater to line ] and this weekend I saw somewere somebody had an improved version with out a check valve , now that its a week day , I can'nt find that link , 2 ? , is the check valve a need it item [why or why not] then where can I get one , I know where I could have one made but its my only ride right now and to have it made they would want the lod one or all the specs. It would be a lot easyer if I could buy one premade .