Onan Generator Radiator Service

helloroad · 09-03-2011, 10:34 AM

we have a 10KW Onan Genset on our 2007 Mountain Aire. I checked the manual and just had a couple of questions on doing the job.

The unit holds about 6 quarts of anti freeze. I was told that the current onan has a Extended Coolant, but when I read the book it recommended a good quality Ethylene Glycol anti freeze. Is that the ELC?

The radiator drain is on the bottom with a 3/8 inch drive access. It looks like the overflow reservoir has to be removed to get access to the radiator cap.
There are three hoses attached there, one goes to radiator, one to the overflow and one is a vent. It also mentioned I should replace the 14# radiator cap as the rubber seal can go bad.

Is there any product I should use to flush the radiator? The current radiator fluid is blue in color and looks very clean. Never been changed.

Are they any hidden pitfalls I should be aware of on this job? The book also mentioned using a thread compound on the drain screw so I am assuming it might be a little tight getting out.

I contacted Cummins in our area and they want about 3 hours labor to do this job. That cost alone is about 350 dollars, so wanted to save myself a few dollars.

Thanks for any advice you can give me.

Have a great week.

Rick

Skip426 · 09-03-2011, 04:33 PM

Hi there, my gen set is a 7.5, so there are some of your questions I can't answer. But I'll do my best on the others. Both regular and extended life A/F are glycol base; I had to run to my garage to check. Any new EL A/F you buy will probably be red/pink. Is 6 quarts the total coolant capacity? If so you only need 3.5 qts of A/F, or 6qts pre-mixed. There are products for flushing rads/cooling systems, but in a do-it yourself case they add to the disposal problems. Catch all the drained coolant for recycling/disposal, IT'S POISON, keep pets away, a small amount can kill. If you choose you can fill the system with water and run the set till it's hot then re-drain; dispose of this with the other coolant. Thread compound/sealant, is to make sure you don't have leaks. Check with your local parts supply store , to see if they can test the rad cap or have a replacement available. Low hour cap , might not need replacement. Good luck

helloroad · 09-04-2011, 04:01 AM

Skip

Thanks for the all the detail. The radiator holds 6 qts total. I think I can buy a premix at the local auto store. I plan on just running water thru it and all the fluid put in a container and take to local business near our home. I know they accept oil so assume they would take anti freeze.

Will also do the oil change and will purchase the Onan filter from Cummins. Not sure if NAPA would have one.

How often do you change your coolant. We sre scheduled for service at
Spartan but they only do oil changes on Gensets. So decided to do both here and save a few dollars

Thanks again for the help.

Rick