coarsegoldgg Report post Posted August 25, 2010 We had the radiator replaced on our 2003 Monaco Windsor after 41,000 miles in May of this year and now have a leak between the transmission cooler and the engine coolant. The repair shop is saying fix the radiator again while others are saying install an exteranl radiator cooler. Does anyone have any experiance with this problem? Share this post Link to post Share on other sites
wolfe10 Report post Posted August 25, 2010 This is a not uncommon problem with some of the Monaco cooling systems. I would first call the new Monaco/Navistar and ask for their latest recommendation. I know of at least one after-market company familiar with this problem and its solution-- might check with them as well: http://www.rv-chassis.com/radiators.html A separate cooler for the transmission is a reasonable option. The big thing right now is to get ALL the coolant out of the transmission and its lines and all the ATF out of the engine cooling system. Brett Share this post Link to post Share on other sites
coarsegoldgg Report post Posted August 25, 2010 These are great suggestions and I will let you know what I find out. It appears that no coolent entered the transmission but there is a ton on transmission fluid in the radiator. The current facility that I'm at wants to just repair the radiator and put it all back just as it was from the factory. Problem is I just went through this whole process 3 months ago and installed a brand new radiator. There has to be a better way! I've written Monaco and hope to hear from them this morning but I'll try to get the shop to call them also. Thanks George Share this post Link to post Share on other sites
coarsegoldgg Report post Posted August 25, 2010 Received a reply fromMonaco and they say an external cooler is a doable option and referred me to their parts department. They couldn't give me any information on size or mounting options and the shop I'm at doesn't want to do th job without guidance. I've contacted the referenced supplier and I'm waiting for their reply. Also, what do I need to do to flush this mess out of the cooling system? Any suggestions? George Share this post Link to post Share on other sites
coarsegoldgg Report post Posted August 25, 2010 Finally got information on appropriate external cooler but unfortunately couldn't find one in Yukon. Could take up to 2 weeks or more to get one and then we would have to figure out how to get it through customs. Bottom line, radiator is being removed and sent off for repair. Still waiting for suggestions on how to purge the system of all the oil. Looks like nothing went into the transmission and the oil that went into the antifreeze collected up top in the overflow container for the most part. The shop is proposing flushing the engine with water and then putting baking soda in after reinstalling radiator - run at temp for 20 minutes and flush again, repeating 3 times and then fill with water and run for several days before draining again and filling with antifreeze. Any comments? George Share this post Link to post Share on other sites
Sundancer268 Report post Posted September 4, 2010 Years ago we used dish washer detergent or TSP from the hardware store to clean and flush an oil contaminated system. I do not know how that would work with the newer cooling systems. I am sure that an Auto Parts Store or Radiator Shop could supply the required information. Share this post Link to post Share on other sites
tireman9 Report post Posted September 5, 2010 I would think that having the radiator fail after only 3 months would be considered proof that the replacement radiator was defective to start with. Radiators are not particularly "high tech" so in my opinion there is little reason for them not to last 100,000 miles. Do you think truck companies would tolerate a failure at 41,000 miles never mind 3 months? You may not be covered under a reasonable drivetrain warranty (5 year 50,000mi) but someone needs to answer why the failur occured in the first place. While oil in the water isn't something you want I would be surprised if it did damage. However water in the transmission and low trans fluid ("ton of trans fluid in the water" means "tons not in or cooling the trans). This low oil could spell MAJOR long term durability problems down the road. Who sold and installed the defective replacement radiator? Are they willing to stand behind their product? If not why not? Are they willing to stand behind and fix the damage to the trans that might have been caused by their defective replacement radiator? Have no idea what baking soda is supposed to do to the trans oil in the engine. Think the soap would work better. Share this post Link to post Share on other sites
