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Topic: Radiator repair (Read 1098 times) previous topic - next topic

Radiator repair

We have a 1994 40 foot diesel pusher with a 300 Cummins. We discovered we were getting transmission fluid in the radiator and extremely low on transmission fluid. We replaced the transmission fluid and got to our camp spot. So assuming we have a leak in the heat exchanger. Need to know if you can unbolt the heat exchanger from the radiator without removing the whole radiator to have it repaired.

Re: Radiator repair

Reply #1 –
You will need a new transmission cooler. The OEM transmission cooler is an integral part of the radiator. At least in our 1993 Grand Villa.  There is a breakdown of the transmission cooler. What that means is when the engine is running the transmission fluid is being pumped into the engine cooling system. That's not so bad, but when you turn the engine off the engine coolant is going into the transmission not good as it contaminates the clutches in the Allison transmission and the recommended repair is a transmission rebuild/replace. You can get the transmission flushed but you are only setting yourself up for transmission failure down the road. You will also need to replace the transmission cooler. You have two options there: get an OEM radiator or plumb in a new cooler. I had this exact problem several years ago. I will gladly answer any question in regards to this you can PM me or call me at six 0 three 3 one five 8 two eight 0. My repair was not cheap and took several weeks to get completed. I would not recommend driving the coach further I don't believe you will get very far before you have a total transmission failure. Do a forum search on transmission failure you should find my table of woe.

Roland
1993 U280 4341
2010 Jeep Liberty
The Pied Pipers

Re: Radiator repair

Reply #2 –
Search for My Allison transmission is acting up under Foretravel tech talk.

Roland
1993 U280 4341
2010 Jeep Liberty
The Pied Pipers

Re: Radiator repair

Reply #3 –
Roland, Thanks for your reply. We are camped in the forest in Central Oregon and will be here another three weeks. So not close to anywhere we could have this worked on. Do you think I can reroute the fluid that goes to the heat exchanger back into the transmission if I drive carefully? Thanks.

Re: Radiator repair

Reply #4 –
Quote from: Roland Begin –
Search for My Allison transmission is acting up under Foretravel tech talk.

Roland


or keywords transmission cooler with user Roland Begin  ;)

My Allison transmission is acting up

(Reply #54 seems to have the pertinent details...)
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Radiator repair

Reply #5 –
To not have to deal with radiator repair, could one add a separate tranny cooler and just seal off radiator's tranny connections?

Re: Radiator repair

Reply #6 –
Quote from: Barry & Cindy –
To not have to deal with radiator repair, could one add a separate tranny cooler and just seal off radiator's tranny connections?
That is what we had done. It required plumbing the transmission fluid AND the engine coolant to the newly installed transmission cooler.

Roland

Roland
1993 U280 4341
2010 Jeep Liberty
The Pied Pipers

Re: Radiator repair

Reply #7 –
Quote from: Suttons60 –
Do you think I can reroute the fluid that goes to the heat exchanger back into the transmission if I drive carefully? Thanks.
I can't really answer that question I can only tell you what we did. Maybe someone that knows more about the mechanics of this will chime in on your suggestion of running without a transmission cooler. We had our coach towed to an Allison dealer for repair. We are fulltimers so it was a bit of an inconvenience.

Roland
1993 U280 4341
2010 Jeep Liberty
The Pied Pipers

Re: Radiator repair

Reply #8 –
I believe the answer is yes, especially if you have a temperature gauge.

Re: Radiator repair

Reply #9 –
Quote from: Suttons60 –
Roland, Thanks for your reply. We are camped in the forest in Central Oregon and will be here another three weeks. So not close to anywhere we could have this worked on. Do you think I can reroute the fluid that goes to the heat exchanger back into the transmission if I drive carefully? Thanks.
If you are sure that coolant didn't get in the transmission and contaminate it, bypass the radiator and watch your trans temp carefully. Go slow, stop and let it cool if it gets hot. Remember it will not cool down by idling it without the cooler. Use low gears on hills and if you have a retarder don't use it.
As far as a permanent fix, I don't know if your setup could have an air cooled trans cooler mounted that would get enough air flow to cool it. Rebuilding the radiator might be necessary.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Radiator repair

Reply #10 –
Sutton

When this happened to me it took me a while to discover that the coolant expansion tank had "blown it's lid". I needed to replace that expansion tank.

Roland
1993 U280 4341
2010 Jeep Liberty
The Pied Pipers

Re: Radiator repair

Reply #11 –
Quote from: craneman –
If you are sure that coolant didn't get in the transmission and contaminate it,


As far as a permanent fix, I don't know if your setup could have an air cooled trans cooler mounted that would get enough air flow to cool it. Rebuilding the radiator might be necessary.
The only way to find out if engine coolant found its way into the transmission is to remove the transmission pan and check it out, unlikely that it did not.

Our Allison mechanic did not install a fan driven transmission cooler and as I did not opt for a radiator rebuild he plumbed in a transmission cooler that uses the engine coolant. Has been working well. We also needed to have the transmission replaced or rebuilt as engine coolant had found its way into the transmission. We did have the opportunity to have a rebuilt Allison Transmission installed but as the rebuilder would not give us credit for our transmission core I opted out and had ours rebuilt. Have had no issues with the transmission since.

Roland
1993 U280 4341
2010 Jeep Liberty
The Pied Pipers

Re: Radiator repair

Reply #12 –
Roland, Thank you for all the input and the pictures. My husband almost called you last night but was too late as our time zones are 2-3 hours different. He did get a very small amount of Water in the TF but he has drained it and replaced it with some inexpensive fluid and then will drain that and put high quality fluid in and replace the filters. He didn't have any problem with it shifting whatsoever so thinks it will be okay. Our problem is finding the transmission fluid cooler. Our coach is a 1994 Unihome 280, I think a lot like yours and you said they didn't make that cooler any longer. So we'd like to find one like the one you had put on but you mentioned it didn't give that information on your invoice. Does anyone know what brand of TF cooler it is? There's a picture on Roland's post from two years ago. Also Roland, what would be a good time to call you? We're in the Pacific time zone. Thanks again.
Mickey

Re: Radiator repair

Reply #13 –
Update on 1994 Foretravel 380 Unibody, 300 Cummings, Allison 6-speed MD3060 leak in transmission oil cooler.
Stopped to do walk around and found pinkish, foamy fluid coming out of the radiator burp bottle. Checked transmission fluid level and needed to add about ten quarts. We continued on to our destination, about twelve miles away.
After assessing the problem, we determined the oil cooler on the side of the radiator was not repairable.  Thanks to the help from Roland who had written about his similar problem on the Foretravel Forum, we checked into possible ways to remedy this problem. We had three options: Flush the transmission and hope for the best; Buy a reconditioned transmission with warranty; or have our transmission rebuilt but no warranty. We decided to flush the transmission and see what happened. We disconnected the transmission oil line from the radiator and routed it right back into the transmission before flushing. We plugged both inlet and outlet holes on the radiator. We then flushed it twice with inexpensive transmission fluid. Roland was very helpful and able to find the type of external cooler that had been put on his coach and we contacted the company, Rocore.  They advised us on the proper unit (5-7063B) for MD 3060 transmission and water port size, along with the clamps needed to install this unit. Installation of the external cooler was not complicated on our unit. We cut out a section of the 2 ½ pipe, (the length of the new cooler), that comes out of the bottom radiator and goes back into the engine. The 2 ½ inch water pipe ran parallel to the frame across the back of the motor home. We mounted the cooler to the frame. We had new seven foot, high pressure oil lines made to connect the new cooler to the transmission. I flushed the radiator with dish soap several times there and again after we drove 600 miles home.  We flushed the transmission again and replaced the filters and transmission fluid with Amsoil transmission fluid. Our motor home shifts notably smoother with the Amsoil fluid. Thanks Roland
Costs
Rocore cooler $937.00 after shipping and taxes
Fittings hoses and clamps $415.00
Filters Transmission fluid coolant $405.00
Total cost $1757.00



Re: Radiator repair

Reply #14 –
This is a little off topic, but wouldn't you think someone manufactures an air cooled transmission cooler large enough for an Allison transmission? The cooler would need an electric fan of course. An air cooled transmission cooler wouldn't overheat your engine when it slips the torque converter while climbing steep grades or when using the retarder descending steep grades. The only disadvantage I can think of would be increased time for the transmission fluid to warm up after a cold start. The engine's radiator would probably have a noticeably increased capacity for long steep climbs in hot climates because it wouldn't have the transmission cooling load anymore... I'd investigate this and turn the whole mess into an improvement if possible... You could probably use multiple air cooled transmission coolers in parallel with solenoid valves to close off one or more of them for faster warm up.

I suspect any coolant that leaked into your transmission will boil off when the transmission temperature gets up to 250 degrees, but I'd change the transmission fluid and filter just to be safe.
Scott Cook
1991 U300 36' 6V92TA
Old Town Penobscot 16
1984 Honda VF1100C (V65 Magna)

Re: Radiator repair

Reply #15 –
Our has an air cooled, electric fan transmission cooler and the transmission is an Allison. See picture
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Radiator repair

Reply #16 –
Does it also have a water cooled transmission cooler or just the air cooled one?
Scott Cook
1991 U300 36' 6V92TA
Old Town Penobscot 16
1984 Honda VF1100C (V65 Magna)

Re: Radiator repair

Reply #17 –
As far as I can tell, just air cooled. I think you (or someone) called it a desert cooler.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD
 

Re: Radiator repair

Reply #18 –
I probably thought it was an auxiliary radiator. I saw a Wanderlodge in Amarillo about three years ago with desert coolers installed near the rear wheels. I think I saw that exact same Wanderlodge at Grand Canyon several times a couple of months ago but nobody was around it. I saw it again somewhere else after that, I think in a parking lot in Flagstaff or Phoenix? Those Wanderlodge people really get around! hahaha
Scott Cook
1991 U300 36' 6V92TA
Old Town Penobscot 16
1984 Honda VF1100C (V65 Magna)