Question on transmission lines and fluids

[spstan]

After driving my 1975 New Yorker I saw a small pool of transmission fluid on driveway. I think one of the lines has developed a leak. My mechanic wants $300 to replace the lines (over the phone estimate). I was thinking of cutting the original steel lines close to fittings and splicing in a piece of rubber hose with clamps at either end. Talking to an engineer friend and he said the hose had to be made of a material resistant to the caustic (right word?) effects of transmission fluid on rubber. Do they make any such material? Or do they have the complete hose with fittings made of this material that I can put on myself? Sure want to avoid a $300 bill.

Also when replacing the fluid that leaked out do I have to use a specific kind of transmission fluid? Cause I do have Ford/Mercury transmission fluid but I don't know if this will work. Thanks for advice. Paul

 

[Snotty]

You an go with rubber hoses and clamps; I did for several years. But, I finally bit the bullet and had them done right by a transmission shop. I recommend you do the same.

I believe Dextron IV is the standard, but I could be wrong.

Another thing: if you aren't driving your car often, leaks from the transmission become common.

 

[Big_John]

First, you really want to figure out where the leak is. The lines usually don't leak... But sometimes they do. They do tend to leak around the shifter and then the fluid runs down and looks like it's leaking somewhere else.

But, if it is a bad spot in the line, buy some 5/16" steel tube at a local parts store. NAPA usually has this. Then get a couple 5/16" compression unions and splice in new tubing. You'll need a tubing cutter.

Some rubber hose won't work with trans fluid. It will swell or break down from the hot fluid. There is hose that will work though, ask for 5/16" trans cooler hose. But if the line looks bad for more then 6" or so, I'd suggest metal.

 

[spstan]

First, you really want to figure out where the leak is. The lines usually don't leak... But sometimes they do. They do tend to leak around the shifter and then the fluid runs down and looks like it's leaking somewhere else.

But, if it is a bad spot in the line, buy some 5/16" steel tube at a local parts store. NAPA usually has this. Then get a couple 5/16" compression unions and splice in new tubing. You'll need a tubing cutter.

Some rubber hose won't work with trans fluid. It will swell or break down from the hot fluid. There is hose that will work though, ask for 5/16" trans cooler hose. But if the line looks bad for more then 6" or so, I'd suggest metal.

Still don't have an answer about transmission fluids. Can I a Ford/Mercury transmission fluid in a Chrysler product . Or does the New Yorker require a specific Chrysler transmission fluid? Paul

 

[Big_John]

Still don't have an answer about transmission fluids. Can I a Ford/Mercury transmission fluid in a Chrysler product . Or does the New Yorker require a specific Chrysler transmission fluid? Paul

You'll get a lot of answers on that one. ATF+4 is backwards compatible to the Dexron that they originally used, so that will probably be your best choice.

 

[bronze turbine]

ATF +4 is the superior fluid. The Ford fluid would work if it's Mercon, but if it's F-L-M it might cause hard shifts and harsh engagement. I know some people will say the F-L-M works great in the Torqueflite, and in fact the instructions that came with the shift kit my brother installed in his New Yorker recommended it. The cheap stuff you can find anywhere that's called "multi-vehicle transmission fluid" (but not the ones for foreign cars) is similar to Dexron III and would work fine.

 

[CBODY67]

Dexron III is the equivalent fluid of MerconIV. Most atf bottles have them listed as "DexronIII/MerconIV". Dexron III goes back to the 1968 Chrysler atf, that came after the old Type A Suffix A fluids. So if you have some, use it. Then after the first of the year or whenever, drive the car enough to get things good and warm (over 10 miles) and do a complete fluid/filter change using the desired fluid.

The Type F Ford atf will work, too. It has a bit more "grab" on initial engagement of the clutch packs, which is why the hot rodders liked it.

In the short term (which might turn into "long term" if it works well), using a short length of appropriate rubber hose (seems like reinforced fuel line has been used successfully?) and clamps.

Enjoy!
CBODY67

 

[57fury440]

What about buying some pre bent lines with fittings in place and replacing them yourself. I know that they make them for the early seventies Mopar C bodies and maybe they would work on yours. I repaired the lines on a daily driver 57 Plymouth Belvedere with transmission cooler line and hose clamps. I ran it that way without any leaks for almost 10 years. Like Big_John said, you could buy some tubing and make your own. It is not that hard.

 

[BAD69FURY]

After driving my 1975 New Yorker I saw a small pool of transmission fluid on driveway. I think one of the lines has developed a leak. My mechanic wants $300 to replace the lines (over the phone estimate). I was thinking of cutting the original steel lines close to fittings and splicing in a piece of rubber hose with clamps at either end. Talking to an engineer friend and he said the hose had to be made of a material resistant to the caustic (right word?) effects of transmission fluid on rubber. Do they make any such material? Or do they have the complete hose with fittings made of this material that I can put on myself? Sure want to avoid a $300 bill.

Also when replacing the fluid that leaked out do I have to use a specific kind of transmission fluid? Cause I do have Ford/Mercury transmission fluid but I don't know if this will work. Thanks for advice. Paul

I just went through this myself. I had a leaky steel line where someone had spliced in a union years ago and that was the source of my leak. I removed the old line and used it as a template. I remade a new steel line using 5/16 line, double flared the ends and added the connector ends, leak fixed!

 

[CBODY67]

For a "top-off", which is what I perceive the OP desires, his existing MerconIV fluid will work fine.

No arguments about ATF+4 being superior (due to its semi-syn formulation, compared to plain "dino" for DexIII/MerconIV), but there is a cost component to that. Just like the DexVI full-syn costs more than DexIII.

Back in the days before DexVI and ATF+ fluids, many hot rodders changed their Dex fluids for Ford Type F fluids. Why? higher friction co-efficients at initial apply of the frictions. Felt like it had a mild shift kit in it. NOT harsh by any means, just quicker and firmer. The only HP ATF we had back then was B&M Trick Shift. Reading the literature, it had the same benefits of using Type F, but it was a unique blue atf. So we started to call "Type F" fluid a "shift kit in a bottle" for GM and Chrysler automatic transmissions.

At sometime in the 1980s, Ford ceased to license Type F as DexIII became their new spec fluid. Then their Mercon atfs appeared with friction modifiers to tolerate lock-up torque converters needing smoother lock-up engagement.

Before Chrysler put the atf filter in the trans oil pan, it was inline. Held in with . . . rubber hoses and Corbin wire clamps.

Happy Holidays!
CBODY67

 

[emsteere]

I purchased pre bent lines with the flare fittings in place. A little arm wrestling to put in between the engine and K frame, but pretty simple otherwise. Certainly not $300 worth of parts and labor. $45 for the pair.