rectangle tank under radiator connected with radiator hoses

[Bajasoon]

Hello,
I have a 2004 winnebago journey with 300 cummins engine. just got home from long trip and after parked, I see fluid on the ground and dripping from...not the radiator, but a rectangle box / unit just under and likely attached to the radiator. seems separate though. But radiator hoses go into it, then out the other side. It lies flat against bottom of radiator. Not sure if seam is leaking or just the hose where it connects to it. Have looked everywhere and at diagrams I could find, but all refer to the plastic overflow tanks on top. That is fine as changed that 2 years ago. This is, as mentioned, a rectangle shape metal box / unit directly under the radiator.
Any one know what it is? It also seems to have metal fittings and may run to HW heater etc.
I'm at a loss!
Thanks for any info
Dawn

[JaminSamin]

From your description I’d say it’s the transmission cooler.

[Jon_C]

Sounds like the transmission cooler. If so there will be 2 radiator hoses and 2 smaller braided hoses going towards transmission.

Is it antifreeze or transmission fluid leaking?

[Rob_M]

Chances are the hose clamps just need tightened. Mine was seeping when hot. Go over all the hose clamps (there are a ton of them) while you’re at it. Radiator and intake piping.
BUT also look over all the rubber hoses for cracks and hardness as they don’t last forever. They are likely 19 years old.

If it is indeed coolant, check your coolant level also.

[Bajasoon]

Thank you guys for your response! I'm going to go under and examine it all today...was busy unpacking since returning home. I'll take pictures as well and trace the lines. I do suppose it is a transmission cooler, although it doesn't look anything like any I've seen on line...no fins, and nothing like a "cooler" . It is a solid piece from what I've seen. Today I'll put work clothes on and go underneath more. As far as the fluid, I was trying to determine that. It is brown but not very oily. When up there, I'll be looking at my notebook to check service notes. I believe the trans fluid was changed 2-3 years ago. I guess it wouldn't still be 'pink', and this fluid is brown..but not thick and filthy.
I am surely hoping it is just the hose (s), and will change them out, but I'm now wondering if I can run the engine and will the leak begin even if I'm not moving (working the tranny). Maybe I can see if the tank is also split (yikes!) or if it's just the hose. If I did / do need a new cooler, is that a cummins part, freightliner part, or winnebago ? I assumed cummins, but don't see any 'coolant " parts on the site I went to.
OK...I'll be back with more info, hopefully, and sure do appreciate your help!
Thank you, much, (i didn't even think trans cooler!),
Dawn (Bajasoon)

[Rob_M]

Originally Posted by Bajasoon

Thank you guys for your response! I'm going to go under and examine it all today...was busy unpacking since returning home. I'll take pictures as well and trace the lines. I do suppose it is a transmission cooler, although it doesn't look anything like any I've seen on line...no fins, and nothing like a "cooler" . It is a solid piece from what I've seen. Today I'll put work clothes on and go underneath more. As far as the fluid, I was trying to determine that. It is brown but not very oily. When up there, I'll be looking at my notebook to check service notes. I believe the trans fluid was changed 2-3 years ago. I guess it wouldn't still be 'pink', and this fluid is brown..but not thick and filthy.

I am surely hoping it is just the hose (s), and will change them out, but I'm now wondering if I can run the engine and will the leak begin even if I'm not moving (working the tranny). Maybe I can see if the tank is also split (yikes!) or if it's just the hose. If I did / do need a new cooler, is that a cummins part, freightliner part, or winnebago ? I assumed cummins, but don't see any 'coolant " parts on the site I went to.

OK...I'll be back with more info, hopefully, and sure do appreciate your help!

Thank you, much, (i didn't even think trans cooler!),

Dawn (Bajasoon)

You are used to seeing a fluid to air cooler. What you have is a fluid to fluid cooler. The “fins” (actually multiple small tubes) are on the inside.

Cars with automatic transmissions have the trans cooler built into the radiator.

[Forza Bill]

Red Fluid leaking?

[Bajasoon]

Hello,
Thanks again for your responses. I took some pictures but will have to learn how to upload them here! One was of the liquid on my finger. It's almost clear, slightly tinged brown, not pink at all. Leak has stopped with RV at rest. Yes, it has 2 radiator hoses..in and out..and 2 braided lines that go into brass (?) fittings into the cooler. I agree it is the trans cooler. (It's the rubber hose from radiator into unit that is leaking).
I haven't lost much fluid according to the resevoir tank. I think I could drive it to a shop about 30 miles away. I would prefer the Kenworth shop, but that is about 60 miles away. i think they might be more familiar but will ask both shops if they can / will change hoses and check all fittings and clamps. Or do you suggest not driving it at all? I could keep checking fluid level.
My next question is, from things I've read, is there a chance the coolant fluid would be leaking INTO the transmission fluid?! This, I understand, would be a disaster. If it is just a matter of the worn hose and clamp leaking out, as it ENTERS the cooler, do you think the trans fluid circulating in there will be contaminated? Will a shop be able to test trans fluid for coolant...test radiator coolant for trans fluid?
A lot of questions, I know! One wonderful, blessed thing is...I just drove her 3,448 miles, always checking underneath for such things, and she waited until parked back at home to display her need of new hoses. How lucky was that?!!!
She is a running machine...and God is good. :-)
Thanks, again, for any further advice. This forum is wonderful.
Enjoy the weekend,
Dawnaltia (Bajasoon)

[Jon_C]

Is the hose cracked and leaking or just dripping out near end of the hose? If so, may just tighten the clamp a bit. It’s common for this to happen.

If your going to drive it to the shop check the coolant level first, and keep an eye on the temp when driving.

It would be rare for the fluids to mix together but not impossible.

Pull the transmission dipstick and look at the fluid on it. Should be red and clear not milky. If its milky don’t drive it, it’s contaminated.

If transmission fluid looks good and you have coolant should be good to drive to shop.

[Rob_M]

It’s highly unlikely that it has an internal leak. Tighten the clamp and see if that stops the leak.
Take it to the shop and have all the rubber hoses inspected and replaced if needed for piece of mind. It’s apparent you would not be comfortable doing this yourself. They all should be tightened, this is part of normal maintenance.

Any shop can do this.

[Bajasoon]

Hello..and thank you all for responses. I'm parked now at home and it will be a while before taking her to the shop, especially since it doesn't leak while parked. The trans fluid is not milky,but also a bit browner than red. Still have to check when that was changed and maybe have it changed again. I've tightened the clamp on the leaking hose but it was pretty tight already. I do suppose those hoses may be 19 years old...so I will have the shop change them. $$$ I know, but much as I enjoy doing mechanical things, my body just couldn't approach that job anymore!
The resevoir tank is still about where it usually is. I really think the leak just started within the last few miles of the 3,500 mile trip. Lucky me!
When ready to drive it to the shop, I'll run it here at home for some time and see how much it leaks. And bring gallons of water / antifreeze with me.
I'm up on a mountain in Vermont with dusty dirt road, so before I make appointment with the shop I'll spend time going over everything to make sure of anything else I need done. I don't like going up and down this road anymore than I have to. Unlike most, I park for the summer season and work here...then when most others are closing their's up, in autumn, I'm getting ready to head south again. :-)
Thank you all, again. Have a safe and fun summer!
Cheers, Dawn

[doorguy]

Sounds to me like you need to change the tranny fluid if you don't know when or if it was ever changed. When I went to the Freightliner traveling 3 day schooling, the instructor spent some time on the Allison transmissions which for motorhomes like ours are the 3000MH model. In our vintage of Journeys, ours is 04 also, they came with "dino" based tranny fluid. They didn't switch over to TransSynd(synthetic) till about Jan 04 or so, ours was a Dec 03 build date so the chassis/tranny was manufactured in the fall of 03. Alllison recommended changing the "dino" fluid out to the TransSynd or one of Allsions recommendations for synthetic fluid; there are others than TransSynd that meet their specs. I believe if yours is already Transynd equipped there will be a sticker placed up near the top left side of the radiator compartment(from the rear) that will specify that it has synthetic fluid.

[Bajasoon]

Hello to all reading this...and thank you, Doorguy, for sharing the info you learned about our motorhomes! Yes, my chassis is also 2003.
So my records show trans fluid and filter were changed in 2018. I don't remember if I actually pulled the stick and made sure it was fresh fluid (which I will this time), but my shop is well known and respected, so I do trust that it was done. They are mostly a big rig shop but are getting into RV's more and more and thankfully so as Vermont has a shortage of those.

I will look up how often trans fluid should be changed, but seeing how it is no longer 'pink', and 5 years out, I will have it done again if not too much $.

Thank you, again, all, for all the info...
till next time...Cheers,
Dawn

[Bajasoon]

HI again,
Barry, (doorguy) I do have a Transynd sticker. I'm thinking that it was changed out from older type fluid when I had the service done. The sticker doesn't look that old. (I don't have service records from before 2016 when I purchased). I don't think much was serviced as it only had 21,200 miles on it. But fluid isn't pink, and the invoice from that service lists the filter at $17, so they only changed the spin on. This time I think I should get the internal one changed as well. ? I have about 66,000 miles on her now.
I saw, too, that you use a Ready Brake system...as do I.
I really like it. When installed, I had them also install a little light on the dashboard that comes on when the tow car brakes are applied. This has saved me a few times when the cables under the pedal, or another issue, needed adjustment and I knew I was dragging the car brakes. My rig came with a Blue Ox hitch and so I need to use an "adapter" ( from Ready Brake) ...a metal column about 4-5 inches tall that the cable runs through and keeps the cable up off part of the hitch. I have bought new cable 2x as the plastic wears off from rubbing through the small hole. Now I just don't replace it. I keep my eye on the cable and it seems fine. I'm wondering how you like the system? I don't see many out there!

I've been reading a lot about the transmission. It seems I may have a 2000mh and not a 3000. I have a serial # written down that I believe I got from Freightliner a few years ago when I called. But when I google that # (6310320663) it seems to be a 3000. My chassis is, I also believe, a 2003. I will call Freightliner again and also try Winnebago but have a feeling I should go under and find the actual plate and see what is stamped on.
My rig was in great shape when I bought it in 2016, but, unfortunately, the main volume book of manuals was not with it. Over the years I've been filling a notebook with downloaded / printed out info. What I never knew...and just learned...is that I can check the condition (basics) of the trans by using the touchpad for codes!
Never knew that!
But, I shouldn't complain...the one (owner's) manual that did come with it DID tell me where the coffee cup holder is! Thank goodness for that.

Seven years and I'm still learning even the basics! Thanks, everyone, I learn most everything right HERE!
Safe weekend, Dawn