1995 Tioga Montara Class C on a Ford E-350 chassis, 460 V8, E4OD transmissionHas recently started weeping fluid at both connections to the auxiliary cooler. Just a few drops have slid down and are hanging on the line that runs horizontally below and behind the radiator. No detectable drop in fluid level, yet.Recent switch to synthetic may be a little too slick for the old connections. Strange that both are apparently weeping equally, not just one.Can anyone identify the brand of cooler in case I need to replace the lines? I have posted photos here:http://bit.ly/2RZEajnAlso getting the specs will help me decide whether I want to upgrade to a new and higher capacity cooler. The Hayden chart implies cooler ATF is a very good investment: Hayden chartMeanwhile...the left hose clamp is not loose at all. Very tight. And the photos suggest the leak is actually above the clamp, at the fitting.Next step would seem to tighten the fitting just a bit.Constructive suggestions welcome. Thank you.

I'm going to bet that it is the hose and not the fitting. The greasy accumulation on the fitting hex may have migrated upward on to the hex. Transmission fluid is pretty thin and as it leaks it will pick up dirt. The fresh dirt will soak up the fluid and more dirt will accumulate. Add some wind and a little rain and it could very well look like what you have. I'd replace the hoses any way because of the age and the end looks like it has started to bell from being squeezed by the clamp for a very long time and the heat probably hasn't helped any. You can also make sure the fittings are tight when replacing the hoses.Make sure the replacement hose is good for transmission fluid as well as the amount of heat it will be handling.

WesternHorizon wrote:1995 Tioga Montara Class C on a Ford E-350 chassis, 460 V8, E4OD transmissionHas recently started weeping fluid at both connections to the auxiliary cooler. Just a few drops have slid down and are hanging on the line that runs horizontally below and behind the radiator. No detectable drop in fluid level, yet.It looks like you're correct that it's actually just a rubber hose clamped onto a barbed screw fitting. As such, you have three points of failure. If the hose is original, it may be sweating. Even if not the hose, if original, time to change it out. The second point is the hose to connector with the clamp. As with any mechanical clamp, the hose could now have gaps allowing fluid to escape regardless how tight it is. The last location is the connector to the cooler and the O-Ring could be worn.Also having an older unit, I found the most likely culprit on those flexible hoses are the hose itself. Sweating is an early warning sign of a impending failure. A Motorcraft KM1938 hose and a set of Hayden 394s will run about $45 and easy to replace. Cheap to replace everything with new, so don't put it off too long as hose failure is never pretty.

X3 on starting with replacing the hose, clean up the area and observe.

A little word of caution, switching from mineral based Dexron-Mercon to a synthetic ATF in the E4OD will cause transmission failure down the road. Ford has never recomended any synthetic fluid for the E4OD, only Dexron-Mercon with a timely fluid and filter change, nothing more.

SidecarFlip wrote:A little word of caution, switching from mineral based Dexron-Mercon to a synthetic ATF in the E4OD will cause transmission failure down the road. Ford has never recomended any synthetic fluid for the E4OD, only Dexron-Mercon with a timely fluid and filter change, nothing more.There is a vast range of opinion on this. I read dozens of posts before focusing in on a former Ford transmission engineer who has been in the Ford RV forum for close to 20 years. My take is that he knows what he is talking about.I added his main statements at this page because of the formatting and many linkshttp://bit.ly/2RZEajn

Radiator aux cooler: Leaking fittings | Good Sam Community

Chum_lee
Explorer
Jan 24, 2019
Use the proper factory clamp (size and style) with fresh factory lines and it won't leak. The clamp shown is an aftermarket clamp and it is too big.

Chum lee
maillemaker
Explorer
Jan 24, 2019
Mercon is extinct. Your first statement is correct.

Thanks!

Steve
time2roll
Nomad
Jan 24, 2019
I would get rid of the hose/barb fittings and go with flare fittings.
Probably bend my own steel lines too.

Otherwise just get new hose and use non-perforated clamps.
WesternHorizon
Explorer
Jan 24, 2019
Thank you all for the info.

mobeewan wrote:
I'm going to bet that it is the hose and not the fitting. The greasy accumulation on the fitting hex may have migrated upward on to the hex. Transmission fluid is pretty thin and as it leaks it will pick up dirt. The fresh dirt will soak up the fluid and more dirt will accumulate. Add some wind and a little rain and it could very well look like what you have.

I think you are correct, there is some "wicking" going on. Thanks.
WesternHorizon
Explorer
Jan 24, 2019
maillemaker wrote:
So I think what it says is that Mercon V was reformulated in 1996 to work in either Mercon or Mercon V transmissions.

Or is it that you have to use Mercon only in pre-1996 transmissions?

Mercon is extinct. Your first statement is correct.
maillemaker
Explorer
Jan 24, 2019
So I think what it says is that Mercon V was reformulated in 1996 to work in either Mercon or Mercon V transmissions.

Or is it that you have to use Mercon only in pre-1996 transmissions?
WesternHorizon
Explorer
Jan 24, 2019
SidecarFlip wrote:
A little word of caution, switching from mineral based Dexron-Mercon to a synthetic ATF in the E4OD will cause transmission failure down the road. Ford has never recomended any synthetic fluid for the E4OD, only Dexron-Mercon with a timely fluid and filter change, nothing more.

There is a vast range of opinion on this. I read dozens of posts before focusing in on a former Ford transmission engineer who has been in the Ford RV forum for close to 20 years.

My take is that he knows what he is talking about.

I added his main statements at this page because of the formatting and many links

http://bit.ly/2RZEajn
SidecarFlip
Explorer III
Jan 24, 2019
A little word of caution, switching from mineral based Dexron-Mercon to a synthetic ATF in the E4OD will cause transmission failure down the road. Ford has never recomended any synthetic fluid for the E4OD, only Dexron-Mercon with a timely fluid and filter change, nothing more.
Dave_H_M
Explorer II
Jan 24, 2019
X3 on starting with replacing the hose, clean up the area and observe.
ItsyRV
Explorer
Jan 24, 2019
WesternHorizon wrote:
1995 Tioga Montara Class C on a Ford E-350 chassis, 460 V8, E4OD transmission

Has recently started weeping fluid at both connections to the auxiliary cooler. Just a few drops have slid down and are hanging on the line that runs horizontally below and behind the radiator. No detectable drop in fluid level, yet.

It looks like you're correct that it's actually just a rubber hose clamped onto a barbed screw fitting. As such, you have three points of failure. If the hose is original, it may be sweating. Even if not the hose, if original, time to change it out. The second point is the hose to connector with the clamp. As with any mechanical clamp, the hose could now have gaps allowing fluid to escape regardless how tight it is. The last location is the connector to the cooler and the O-Ring could be worn.

Also having an older unit, I found the most likely culprit on those flexible hoses are the hose itself. Sweating is an early warning sign of a impending failure. A Motorcraft KM1938 hose and a set of Hayden 394s will run about $45 and easy to replace. Cheap to replace everything with new, so don't put it off too long as hose failure is never pretty.

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Radiator aux cooler: Leaking fittings

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