Engine/Transmission (1994 - 1998) transmission cooler lines

[gcorron]

Guys,

I've read the threads on these lines, well guess what??? Now MY lines are leaking. :--)



I've got a "band-aid" on it for the moment, :{ but need some advice that does not seem to be clear in the previous threads. Here are my questions:



1) It appears to be a 1/2" line, that's what the other threads say, if I get the standard ends that come with that, will that mate up to what is there?



2) If I decide to remove the quick disconnects under the exhaust manifold, do I need to replumb? Will 1/2" NPT fit in the transmission and the cooler under the exhaust?



3) WHAT is it leading to under the EXHAUST manifold? I mean, the cooler is up front with the radiator, so WHAT would be under the exhaust - the hottest part of the engine for crying out loud.



4) Not seeing up close real good (you 20 year old guys have got SO MUCH to look forward to :-laf ) I can't see the fittings in the part under the exhaust, are they hard to get out? are they affected by the heat of the exhaust?



Yeah, I can figger this out myself, but let's face it, this forum is a wealth of knowledge with the "been there, done that" experience. It is always nicer to crawl under da hood with what ya need before you get there.

 

[Joe G.]

The cooler under the exhaust manifold uses engine coolant. It also serves to warm up the transmission in cold weather.



The cooler lines are 1/2" OD.



The thread in the transmission for the fittings is 1/4" NPT. It's the next size smaller in the cooler under the manifold. The ones under the manifold are kind of a PITA, but not too bad.



you really want to replace the quick disconnects. Both types are no good. You can replace them with compression fittings (cheapest fix). Some people have had trouble with leaks with those fittings. I have not. You can replace all the cooler lines with hydraulic hose. You can buy new flared fitting cooler lines from Dodge (big bucks!!).



You don't say what year your truck is. If it is a '94 or '95 you will have to deal with the temp sensor in one of the cooler lines. If you use compression fittings and trim the stock ridge around the ends of the lines off, you will need a short nipple in the trans to get clearance for the temp sensor. If you replace the cooler lines with hydraulic hose you have to use some pipe fittings for the temp sensor in the side of the trans or you may have problems getting OD to work.

 

[gcorron]

Thanks Joe,

That should do, I'll have to get under the truck and have a go at it after I make a quick trip to NAPA. I've got a lot of fittings at the house, so should be able to cover it if necessary.



Trucks a 97. I bought it from my brother in '02. The only problem he had is to replace the starter, other than that, nothing but normal maintenance, except I did have to replace BOTH rear seals... . BTW, I can now replace one in about 20 minutes.



Thanks again,



George

 

[y-knot]

As the poster said the lines are 1/2" Aluminum, and yes the transmission inlet and outlet fittings are 1/4". What a crappy system, 1/2" lines and 1/4" fittings, oh well. I have been doing alot of work with stock and modified transmissions and coolers lately, and I have in deeded bought the complete factory lines twice now. I would not call them BIG BUCKS, but they are rather expensive. There are three (3) lines that make up the transmission coolant lines, one from trany to manifold heat exchanger, one from heat exchanger to front mounted cooler, and the third from front mounted cooler to transmission. The older trucks had steel lines, but now they only use and offer as replacements, aluminum lines. The ones to the heat exchanger come with the 1/2" rubber hoses attached and all ends made-up. The list on all three lines are just over three hundred dollars, but I looked around and got mine for 1/2 of that. Thats not really that bad when you consider how much goes into the two going to and from the heat exchanger. The real joke is the fittings that adapt the lines to the transmission, they are simple 1/2" to 1/4" brass fittings but Dodge wants almost 80. 00 bucks for the two! I simply went to the local hardware store and got both for under 3 dollars. So, fittings yes they are sinfully over priced, but the lines are what I would consider fair.

Also, before you knock the stock system and try to re-invent the wheel, take a good look at how well it has worked for everyone over the last 12 or so years. With the exception of a few bad plastic fittings, the lines have worked remarkably well. The leaks that some including yourself have had, are simply the product of rubber hoses exposed to heat and normal aging. The belts and hoses are suppose to be replaced every 60,000 miles or 4 years according to the owners manual, but most overlook the transmission hoses and brake hoses.

 

[dshatzer]

Aaaargh

Alrighty then. One of the rubber transmission hoses on She Who Must be Obeyed(SWMBO)'s 98 CTD has developed a dribbly leak (Scientific term, I believe) as of last night, at the connection where the rubber hoses connect with the metal lines. Am I correct in determining the best solution is to get the Dodge rubber hoses and replace the other lines with steel brake lines and fittings ? It needs to be dead on fixed for a trip from MD to MI next week.



Thanks for the assistance and any constructive ideas