kd460

OK, so I am replacing my lines with hydraulic hose. Have been searching and get conflicting information. I would like to know what size is the threads for the fittings at the heat exchanger. Based on searchig, am I correct in thinking it is 3/8ths npt female going INTO the heat exchanger (following flow of trans fluid) and 1/2" npt female going out of exchanger?

It looks like some type of JIC fitting that is threaded into the female threads I am questioning. They also look to me to be the same size, but I could be wrong. I guess what I am getting at is, can those jic fittings be removed and standard npt male hydraulic lines be used? I will use all 1/2 inch hydraulic, and use an adapter on the 3/8ths fitting (if I am correct).

If the JIC fittings can't be removed, then what adapters will I need for 1/2 inch male thread hydraulic hose? I plan on eliminating the short anti-drain back section completely.

Just want to have everything ready to go when I do a tranny filter and fluid change, I'll swap out the lines as well. Not worried about the connections at the tranny, just the heat exchanger. Thanks, KD

logskidder

Another member told me the fittings are not pipe or jic but they are a straight non-oring thread ( never heard of such a fitting ) i have yet to confirm this, maybe someone else will chime in. But at any rate just be careful before you try to screw in just any fitting. BTW I cant see how a non-tapered fitting would seal without a oring.

kd460

Thanks logskidder, yes, I read the same thing doing a search. I thought the straight threads were at the transmission?? (which is why I'm just gonna leave the steel lines at the trans and go with 1/2" compresion to 1/2" npt to hydraulic hose).

I also read that folks are using the standard tapered npt with no problems, but have read warnings abut cracking the trans case with the tapered fittings (another reason why I'm leaving that alone).

I guess thats part of my confusion/concern. Might just have to buy a bunch of different sizes and just hope for the best, return the rest. KD

TIMMY22

I took my fittings out of the transmission and brought them to a hydraulic supply house to match them up.

The counterman found them to be NPSM not NPT. They did not stock any NPSM fittings at all.

I suspect DC used NPSM rather than NPT to prevent the average joe or aftermarket company from being able to easily replace or reproduce there overpriced lines.

Dr. Evil

JKM might be able to shed some light on this....

Buckshotram

Is the heat exchanger the tank looking thing near the turbo downpipe? I just took my factory line to my local carquest and had them match up the fittings and make me a line out of hydrolic hose. Ill try to find my recipt and see if it says what they are.

kd460

Bucksotram, yes, that is the heat exchanger. Thanks, that would be great if you could. Sure would save me some down time. Just trying to avoid taking things apart, finding out I have the wrong size/fittings, run back to the supply house, then realize they don't have what I need, go to three other places, get adapters for adapters, or "not in stock" put back together with the old stuff, order parts, then do it all again in a week, well, you probably know what I mean. Thanks, KD