Transmission cooler lines high or low pressure? [Archive] - Jeep Commander Forums: Jeep Commander Forum

: Transmission cooler lines high or low pressure?


elgineddie
02-14-2011, 07:12 AM
Hi Team,
I need to fix my wife's Commander's leaking transmissions cooler lines. Thinking about the fix Turbodave did here at this link. (http://www.jeepcommander.com/forums/album.php?albumid=295)

My question: are these lines high or low pressure? If they're high pressure, what kinda PSI are we talking?

Mongo
02-14-2011, 08:14 AM
Which Transmission do you have? Assuming its the 545RFE, since you sig says you have a V8, only the V6 has the Mercedes trans.

I do NOT know the actual pressures, BUT, if asking for the purpose of selecting hose to use, I would only use Transmission Cooler Hose. Its NOT only pressure you have to worry about, its also compatibility with the trans fluid. NOT aware of the pressures being any higher than other transmissions, so if you use "Transmission Cooler Hose" you should be fine.

elgineddie
02-14-2011, 08:50 AM
Thx, I'll be certain to find hose at my local Napa that's transmission-fluid friendly. Not certain which trans she has.

My main reason for asking is because I wouldn't want to simply purchase 3/8" hose and toss it in place with some hose clamps if this is a high pressure application. The danger of the hose popping off is my main concern.

Mongo
02-14-2011, 09:50 AM
Thx, I'll be certain to find hose at my local Napa that's transmission-fluid friendly. Not certain which trans she has.

My main reason for asking is because I wouldn't want to simply purchase 3/8" hose and toss it in place with some hose clamps if this is a high pressure application. The danger of the hose popping off is my main concern.
Most auto stores carry "Transmission Cooler Hose", designed specifically for tranmission cooler lines, that is what you want to ask for, if you ask for "Transmission Fluid Friendly Hose" you might get something that is NOT up to the pressures in the cooler line.

I would think the stronger screw clamp type clamps would be better than the spring clamps. I've used the screw type clamps on trans coolers for older A-727 & A-904 RWD trans for additional coolers, that the lines were all solid flare fittings and NOT had any problems. Some of the FWD trans I have had, had spring clamps OEM on the trans cooler hose, but I can confirm the screw type clamps can clamp more than the spring, so better safe than sorry.

elgineddie
02-14-2011, 01:33 PM
10-4, understood.

As for longevity, I've emailed Turbodave to ask for a long-term check-in. He's had his fix in service for about a year now and I'd love to know how it's held. If he responds to me I'll post it up.

ALSO, any idea how to tell which tube is traveling in which direction?? I'd like to add an in-line Magnefine trans filter and need to know in/out direction of travel.

GeeEssFore
02-14-2011, 08:47 PM
I just had the same problem today. I also will be trying his fix. Ive read that Napa has better clamps then the worm type. I am just wonder what size trans hose to get.

elgineddie
02-14-2011, 09:52 PM
The hose size is 3/8" ID transmission hose. Don't use fuel line.

GeeEssFore
02-15-2011, 05:56 AM
Ya I was just going to get trans hose from Napa

Mongo
02-15-2011, 10:23 AM
I just looked up Transmission Cooler Hose last night at RockAuto.com. They sell Gates Transmission Cooler Hose that is rated for 400PSI.

IIRC, most fuel injection hose is rated for 60-85PSI.

I don't think the line pressure gets that high in the cooler lines, BUT, pressures inside the trans can be in thousands of PSI. So, I think its a matter of pressure surges in the system can make their way through the systems sometimes and thus to the lines, so you have to have a pretty high pressure hose to ensure they won't burst over years of use. I could be wrong on that.

And its NOT only pressure rating, gasoline and oil hose can have different chemical make-up and using the wrong fluid in the hose than intended by its design, can result in weakening the hose, and then you'll get leaks or have it burst.

Fuel Injection "Clamps" have always impressed me as being a good design that would clamp the hose very tightely. Maybe NAPA has something even better. As well, you have to have some sort of crimp at the end of the line, if you're cutting metal lines, you can't leave it as a smooth line on the end. Something has to be there to prevent the hose from being forced off the end of the line. You could get a brake double flare tool, and stop halfway through the process, that would leave a nice buldge on the end of the line to prevent the hose from being forced off. Another, the ring for union fittings, either braze/solder it on the end, or just attache a union fitting, that will crimp that ring on the end of the line, then cut off the fitting.

You already have a filter in the trans, why do you need a 2nd or 3rd in the cooler lines? It might reduce flow through the cooler and heat up the trans, as well, the trans can be very sensative to line pressures, and a pressure change from a cooler in the line could effect the trans. Yea, unlikely, probably wouldn't hurt anything, but IMO, you don't need the filter, so why risk it causing any negative effect, even if its unlikely.

On the 5WA580/NAG1 trans, the output line is on the Driver's side, the return line is on the Passenger Side. This is the V6 Trans. I don't know on the V8 Trans.

"Typically" the higher hose from cooler is the return line, but NOT always, and I could be remembering it backwards, so you need to confirm it.

GeeEssFore
02-15-2011, 02:53 PM
I thought both lines are on pass

elgineddie
02-17-2011, 08:46 AM
I thought both lines are on pass(enger side)

Yes, the lines enter/exit the trans cooler on the passenger side of the vehicle but Mongo may be referring to where the lines touch the transmission itself. Since it's my wives Jeep and it's not in the garage now, I can't peek underneath to check if the cooler lines split up and head to different sides of the tranny. I guess the easy way would be to cut one of the cooler hoses (where I'm going to put the in-line filter anyway), get a bucket, have someone start the car briefly and see which way the fluid flows!!

elgineddie
02-17-2011, 08:56 AM
Been reading up on in-line filters for a while and dealing with my wife's leaking cooler hoses has prompted me to be more active in actually doing it.

Here is a pretty good information link (http://www.fourwheeler.com/techarticles/drivetrain/129_1002_automatic_transmission_and_power_steering _filters/automatic_transmission_filter.html) for those thinking of an in-line filter.

-Ed

Mongo
02-17-2011, 09:46 AM
Yes, the lines enter/exit the trans cooler on the passenger side of the vehicle but Mongo may be referring to where the lines touch the transmission itself.
Thanks, thats exactly what I meant, and that was only for the V6 Trans, the V8 Trans could be different and have both cooler lines on the same side of the trans. Most American trans do, this Mercedes trans in my V6 Commander was the first that was different for me.

elgineddie
03-05-2011, 09:36 AM
I'm finally under my wife's Commander fixing this stupid leak.

PRESSURE:
I haven't been able to find out if these lines are hi/low pressure. I changed my focus 1/2way thru the life of this thread to find out the direction of flow so I can install my specialty transmission in-line magnetic filter from Magnefine (http://www.magnefine.com/).

DIRECTION OF TRAVEL:
On my particular 2006 Jeep Commander 4.7 LTD (I don't know which trans mdl) the cooler lines exit the transmission on the top-passenger side and enter the cooler on the top; then return from the lower cooler hose to the bottom-passenger side of the transmission. That is the direction of travel.

IN-LINE FILTER INFO:
From what I understand, if you want to install a high-flow, in-line magnetic filter on a new transmission, you install it before the cooler. If you are installing it on an "in-service vehicle", i.e. greater than 5,000miles, you should install the filter after the cooler. Obviously observing the directional arrow on the filter itself.

PARTS NEEDED:
Finally, if you are doing this fix, you should get (8) hose clamps and (2) nine-inch lengths of transmission hose. Both rubber hoses I removed measured out to exactly 9" each.

-Ed

turbodave
03-06-2011, 08:07 PM
10-4, understood.

As for longevity, I've emailed Turbodave to ask for a long-term check-in. He's had his fix in service for about a year now and I'd love to know how it's held. If he responds to me I'll post it up.

ALSO, any idea how to tell which tube is traveling in which direction?? I'd like to add an in-line Magnefine trans filter and need to know in/out direction of travel.



Here I am!
Sorry I've not been here, but the commander has had absolutely no problems, which is good of course...

So, I gave the trans lines a real good inspection today. They look just the same as the day I fitted them - except the clamps are getting some powdery corrosion just starting on them. I added a picture in my folder if you want to see!

As regards high-pressure lines, just feel the stock lines: They are very soft and not in any way HP rated. I'd be concerned about using HP rated hose, as they might not burst, but you'll probably be limited on just how tight you can get the clamps as the hose would have such little compliance... I used EFI rated fuel lines.

If the Jeep used Dex6 - I might have a concern, but Mopar ATF is not known for being particularly brutal as regards affecting plastics or elastomers.

Final note - I never did fit an NTZ transprotector - but this is simply because I forgot to! It is still in the Box!
This is the only in-line filter I'd use: Depth-media filtration is where you will see benefits on any transmission that already has a pretty good filtration system... These are standard fit on the Audi Dual-Clutch transmissions, and many others, such as the Ferrari California...

I have no connection to NTZ, but have spent many hours working with transmission filtration systems :-)
They are the best!

http://www.ntzfilter.com/sect1b.asp

bob123
03-07-2011, 10:48 AM
Dealer want $418 in labor and $39.20 for both lines. Now I am thinking about doing it myself.

So when you cut the metal clamp parallel with the rubber hose, the clamp will just peel back and then you can remove the line?

Also, how much fluid did you loose?

Mongo
03-07-2011, 12:29 PM
Dealer want $418 in labor and $39.20 for both lines. Now I am thinking about doing it myself.

$418 for labor sounds ridiculous, it does NOT look like it would take that long to replace those lines with replacement parts.

If the $39.20 is for the replacement parts, why NOT just get the replacement parts instead of trying to improvise a fix yourself, that will cost nearly as much?

turbodave
03-07-2011, 04:38 PM
So when you cut the metal clamp parallel with the rubber hose, the clamp will just peel back and then you can remove the line?

Also, how much fluid did you loose?


The stock swages are actually pretty thick. You need to cut through them the full length as best as you can. I'd presonally use a dremel with the thin cutting discs. Just sink the disc into the swage, get a feel for it just going through the thickness, and don't go any deeper! You have a lot of rubber thickness as a 'buffer'.

Just keep putting cuts in there, until you can remove them. Just remember to not cut into the 'bulge' in the hard-line by the swage however!

Don't remove any hoses fully (you can pull them forwards and backwards, but not off the hard-lines) until you have done them all, would be my advise.

Also - degrease the area first so you have a clean working area. And hose away all the shavings with water before you pull the hoses to minimise contamination risk.

Make sure your new hose hasn't got any crap inside of it as well!

I don't know how much fluid you'll lose - It wasn't much - but I did stuff tissues into the hard-lines after removing the hose to 1) prevent junk getting in there and 2) prevent fluid from pouring out.

Have fun - there is no way this job is worth going to the dealer for - only to have him fit hoses which will leak in another 40 or 50K miles... Do it yourself in a little over an hour. :-)

elgineddie
03-13-2011, 09:09 PM
$418 for labor sounds ridiculous, it does NOT look like it would take that long to replace those lines with replacement parts.

If the $39.20 is for the replacement parts, why NOT just get the replacement parts instead of trying to improvise a fix yourself, that will cost nearly as much?

I agree. For $40 I woulda bought the replacement lines instead of dealing with the mess and toil involved in cutting the old clamp and installing new hose.

elgineddie
03-13-2011, 09:15 PM
Here I am!
Sorry I've not been here, but the commander has had absolutely no problems, which is good of course...

So, I gave the trans lines a real good inspection today. They look just the same as the day I fitted them - except the clamps are getting some powdery corrosion just starting on them. I added a picture in my folder if you want to see!


Awesome! Thanks for the long term check-in! I've checked my repair every couple days and it's holding nicely. Hope it'll last.

elgineddie
03-13-2011, 09:22 PM
Dealer want $418 in labor and $39.20 for both lines. Now I am thinking about doing it myself.

So when you cut the metal clamp parallel with the rubber hose, the clamp will just peel back and then you can remove the line?

Also, how much fluid did you loose?

Fluid to add will depend on how much was lost BEFORE the leak was fixed. Judging on how wet the underside of our Jeep was, and the very little I lost during the fix itself, I figured I'd need about 1/2 qt. And that was about all it took.

elgineddie
05-31-2011, 01:14 PM
Well it's been 5,000 miles & about 3 months since my fix. The DIY leaking trans cooler line fix is holding up A-OK! No leaks, no slipped hoses, no issues. Magnefine filter looks good, no leaks around it either.