Community Forums

Randyman1 · 09-21-2015, 08:26 PM

Does anyone know who manufactured the hydraulic oil cooler that sits just below the side radiator on a 07 HR Navigator with the ISX engine? Mine has developed a leak and I figure I can have it fixed, but it appears to be aluminum and if un- repairable I might need to replace it. Also, has anyone else had this problem? Randy

OB-One · 09-21-2015, 09:58 PM

The hydraulic tank on our coach cracked and it is also aluminum. We had it repaired at a machine shop in Salina, KS. Aluminum contaminated with hydraulic oil is repairable but the welder has to have the right equipment and know what they're doing.

Our tank was filled with argon and TIG welded.

Randyman1 · 09-22-2015, 07:13 AM

Thanks for replying OB-One, This is the second time this has happened. The first was just two years ago when we purchased it and the dealership had it fixed. I wondered if I was the only one having this problem, or if it was the norm due to vibration or bad design. I'm going to find out if it is the exact same place having the problem or if it has moved on to a new location. I'll report back what the final outcome is once all fixed up. Randy

jacwjames · 09-22-2015, 06:53 PM

I had a radiator failure back in May, my oil cooler is built into the radiator but in my search for a new radiator I contacted a number of venders.

First thing to do is get a quote from Monaco, then you will have their part number, ask if they can provide a drawing to confirm dimensions. There quote was X2.5 times more then what I eventually paid.

From there you can contact venders and provide them

Radiator Supply House was a vender for Monaco, check with them. They used the Monaco part #

Source Engineering is vender also, they had a competitive quote using the Monaco part # and provided me with drawing to confirm dimensions.

CG& J in Alabama has repaired and or made radiators and oil coolers that work in Monaco. I ended up getting a new radiator from them, they the best price and had a good turn around with reasonable shipping. Good to work with. Once they make a radiator they maintain a database of the design, they may have what you need give them a call.

C,G, & J Inc.

walt2137 · 09-22-2015, 07:40 PM

Yes I have heard of failures on that cooler, Monaco had a lot of cooler problems starting in 01 when they went to aluminum coolers, radiators, CACs and Hyd coolers. There was a rash of Allison trans lost because of a faulty trans cooler in the radiator, Monaco fixed a lot on their dime.

Randyman1 · 09-22-2015, 08:14 PM

Jacwjames, I found that out today. I decided I wanted to go with a new one as opposed to having this one fixed again. I called Monaco tech and they were just a little over double what I am to paying Source Engineering for one. I'm hoping this new one with my care will last better than the original. I did ask Jim why they leaked and he thought it had a lot to do with people starting in cold weather and revving the engine before the fluid had a chance to thin down a little bit and caused pressure problems that made them split. He had it in stock, but when he went to pull it and ship to me it had already been sold, proving Walt2137 to be correct that there is some demand for these and I am not alone with this problem. No problem as he is having Radiator Specialists build and direct ship me one in another week. Be glad to put this behind me for a long time. Randy

jacwjames · 09-23-2015, 07:34 AM

Thanks for the feedback on a potential cause for the failure. When I am in the process of leaving a site I will start the engine and let it idle it air up the tanks and while we are packing up. Glad to hear I may be doing something right for a change.

Glad you were able to get a cooler from Source Engineering, they do a great job supporting the Monaco line.

Randyman1 · 09-23-2015, 10:31 AM

For what it is worth, if you have a coach similar to mine and the cooler is separate and located on the driver side under the radiator the part number is #S01807017. $1100 + shipping. I did research and found that the optimum fluid to use has an ISO (International Standards Organization) rating of 46. They have also used Dexron II and not had problems as well. I'm switching to Amsoil Synthetic Multi-Viscosity Hydraulic Oil ISO 46. I'm hoping by going to synthetic that it will not be of concern the temperature at start up. Keep in mind I have no proof that cold starts was the culprit, just going by what Source Engineering mentioned to me. I'm going to change the filter again as well. Fresh fluid for new filter and cooler. Randy

snobus · 04-10-2019, 08:03 PM

Thanks for the info, We ordered one from Source Engineering, shipped and received in 2 days, wife and me installed it the next day, on our way back to Alaska, over 500 miles so far and works perfect...
Jim was a great help.

Bill767 · 04-11-2019, 05:20 AM

Quote:

Originally Posted by Randyman1

Does anyone know who manufactured the hydraulic oil cooler that sits just below the side radiator on a 07 HR Navigator with the ISX engine? Mine has developed a leak and I figure I can have it fixed, but it appears to be aluminum and if un- repairable I might need to replace it. Also, has anyone else had this problem? Randy

Two years ago we had a catastrophic leak of that cooler while traveling in Wyoming. We called Source and they had the exact replacement, that had also been improved over the original model, and they overnighted it to us. It was a messy, but easy job to replace the cooler. Exact plug and play, and we were horrified to find out how much dirt and debris was between the cooler and the radiator.