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Transmission coolant line

Hannibal_805

NAXJA Forum User
Location
Alabama, USA
Greetings all,
A few weeks ago I was replacing the Transmission coolant line and discovered that the quick connectors on my 1996 Sport are worthless. I feel ashamed for buying them. I have heard that some people have made their own connectors, while I can see how this would easily be done on the front of the hose (radiator side)...the rear poses somewhat of a problem.

I'm unsure what I could replace this http://cpwstore.carpartswholesale.c...57eb1843f043&cpwid=cpw12598912514afeb8f486e15
is the main issue.

I'm just tired of struggling with these connectors only to have the shot right back out by the pressure of the transmission fluid.

Any help on modifying these lines would be greatly appreciated. Surely someone has done this before?
 
ahhhhhhhhh! I HATE those quick disconnects. They are neither quick, nor disconnects after thirteen years of road dirt. I didn't feel like figuring something out though, so I simply bought all new fittings - the quickdisconnect fittings on the transmission actually unscrew, they are standard NPT thread on the other side. Stick a big pair of channel lock pliers on them and they will unscrew pretty well. Dorman makes a set of new lines (624-300, 624-301, 624-334 are the part numbers) and also the screw-in quick disconnect adapters (800-714, you need two.) I got my full set from RockAuto for less than $70.

What you could do is get some brass adapter fittings for the NPT thread and some small brass NPT pipe lengths, screw the adapters into the transmission, and the pipes into those, then use bits of transmission hose (cheap at your local autismzone) and hose clamps to connect the two together. Kinda ghetto, but it'll stay in and you'll be able to get it apart again easily ten years from now. Make sure you use plenty of PTFE thread tape on the NPT threads if you are going to do this - heck, if you use the quickdisconnect fittings make sure you use plenty of tape.
 
Exactly what I wanted to know, thanks so much. This is a tremendous help, hopefully I can have it all fixed it up and ready to get back on the road by Tuesday.

-Han
 
If you are looking for a cheap fix. You can pick up Flexible black transmission hose from any parts store. To connect the hose just cut the steel lines and use 2 hose clamps and a little RTV.
 
Make sure you use plenty of PTFE thread tape on the NPT threads if you are going to do this - heck, if you use the quickdisconnect fittings make sure you use plenty of tape.

actually dont use any of it. it doesnt resist the atf fluid and can break down and clog parts of the trans. NPT threads are designed not to leak. if they do they need tightened or the threads are bad.
 
The thread on the transmission side is metric- M14x1.5. I cut the end of the cooler lines and flared the ends for AN/JIC fittings from McMaster-Carr. You can also get barbed fittings in M14x1.5 and run some good quality hose like Aeroquip all the way to the front.
Check out the link for more info.

http://www.naxja.org/forum/showthread.php?t=999847
 
Guys- I can't thank you enough for your feedback. This was actually the third forum I tried and I think I found my home for future queries/projects. Everywhere else I went were either unhelpful or unresponsive. Truly, you all are awesome.

-Han
 
actually dont use any of it. it doesnt resist the atf fluid and can break down and clog parts of the trans. NPT threads are designed not to leak. if they do they need tightened or the threads are bad.
I can find only one reference stating this about PTFE tape - and it's on answers.yahoo.com, so I take it with a grain of salt. Plenty of aftermarket cooler companies I found are suggesting PTFE tape as well. Also, efunda.com lists virgin teflon as compatible with ATF - it gives it the highest rating. Cole-Parmer's chemical resistance database does not include ATF but gives Teflon an A/excellent rating for everything else, including all other oils and gasoline. I would therefore say it's safe.

As for NPT threads - you're completely incorrect there. Why do you think plumber's dope is needed when installing natural gas lines, which are NPT? I tightened the NPT hardware on my OBA setup down until the threads nearly stripped and I was still losing 5psi a minute out of my tank and could hear the hissing from the driver's seat, after a few wraps of teflon tape on all threads and reassembly it will hold 150psi for weeks at a time.

EDIT: Looks like I was wrong on the NPT threads, they're metric - but still, PTFE tape will not decompose and is good insurance.

http://www.votionspeed.com/servlet/the-569/PTFE-Braided-Stainless-Steel/Detail
PTFE Braided Stainless Steel Lines, -6 AN
SKU:
These lines are sold per foot! Example: (qty: 4 = four continuous feet of this hose)

These Braided Stainless Steel Lines are specially designed to work in any automotive project.
Compatible with the following fluids:

  • High octane gasoline, up to 117 Octane
  • Regular gasoline
  • Ethanol (E85 or E100)
  • Diesel fuel
  • Biodiesel
  • Methanol
  • Nitrous oxide
  • Engine oil (synthetic or regular)
  • Transmission fluid
  • Engine coolant/antifreeze
  • Brake fluid
  • Hydraulic clutch fluid
  • Air Conditioning Refrigerant (R12 or R134A)
  • Air and water
 
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Hmm I've always heard to never use it on anything like that but I could be mistaking it with something else. For me I'd rather not take the risk.at work we had an oil filter. Break down and clog a cam oil gallery killing the cam. If that tape broke down I don't see it doing much less
 
If you are using so much tape that it has a chance of getting into the lines you are doing it wrong. Start a thread or two back with the tape so it is clear of the fitting hole.
 
All right, so since I last checked back in with you guys I've made some progress in between classes and what have you. At this point the situation is this: everything is connected, front and back, soft hosing to hard line with clamps...works perfectly. However where I used the the brass barbed fitting it leaks at the base as kastein indicated it would. I have a couple of choices at this point as I see it. I can remove it (the fitting) and try using one of the little green o-rings at the base that were on the former socket alternatively get some Teflon tape now that I know its safe to use there.

Thanks in advance
-Han
 
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Not sure the base of the barbed fitting will have the right seat for the o-ring to go into, I'd probably throw the o-ring on and ten or fifteen wraps of teflon tape as well for insurance. Make sure you wrap the teflon tape a thread or two down from the tip, as Talyn noted, and also make ABSOLUTELY SURE you are wrapping it in the direction that will keep smoothing it down and tightening it as you tighten the fitting in. Wrapping it the other direction will result in it bunching up, not sealing, and possibly getting into the line as trippled said. It's pretty easy to get it right, just hold the fitting however it's comfortable and visualize tightening it, then make sure you start wrapping such that the spool of tape is being "turned away from" as the fitting tightens.
 
When I do transmission lines, I flare the hard line side (single flare is sufficient, double is real nice (smooth edges), and slide the transmission hose over that - then double clamp. The clamps hold the fluid in, the flair prevents the hose from slipping off.

I like running hard line when ever I can. The exception is between the engine mounted hardline and the radiator, which is rubber fuel line. Transmission hose is not high pressure.

Ron
 
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