Radiator / Coolant Questions...

dashdriver · 11-03-2009, 07:49 PM

Hi Everyone,

So I'm trying to service the engine cooling system by doing a system flush and filter replacement on my 99 HR Navigator. I am not finding any help with either the Cummins or Holiday Rambler manuals since my coach does not seem to be setup like either one says.

I have found the radiator. It appears to be mounted so that there is no radiator cap on top, am I correct? I located the drain valve on the bottom.

I have also found the plastic surge tank. It has a filler cap, probe for the level sensor, a hose coming out the bottom and hose at the top and what looks like a plastic radiator cap on top. My initial thought was this is where you put the replacement fluid after you drain it, since there does not appear to be any other way to get coolant into the radiator.

I drained the system using the drain and got about 7.5 gallons of fluid out. I then went to flush the system and was going to use Fleetguard Restore per Cummins' recommendation. I thought before I put the Restore in, I would put some water in, then the Restore and then top it off with water and then do the 1-1 1/2 hour engine run that Cummins details in its procedure. So I put water in the surge tank and it is not draining into the radiator like I thought it would. I started the engine and let it run for a few minutes with the heater on. The water level in the surge tank went down slightly but not much, so I shut the engine off again after about 5 minutes of running.

The hose coming from the bottom of the "surge tank" appears to go straight to the "coolant inlet" which I'm guessing is attached to the water pump.

So my big question is....do I need to run the engine for longer in order to fill the radiator? Is it not taking water from the tank because it's waiting to get warmer first?

I also found the filter and the valve. I cannot get it off though, anyone have any suggestions? I have 2 different types of filter wrench and it will not budge. I used WD40 on it too and let it sit for a while but it will still not budge.

Any help is appreciated.

Thanks,

Ray

walt2137 · 11-06-2009, 10:54 AM

Ray I assume your engine is a ISC and if so you should get between 10 & 12 gal out, if your coolant was in pertty good shape I dont see a reason for a flush. On our 2000 dyn there is a plastic surge tank with a cap(made by Volvo) that is the correct place to fill and to drain you will need to remove the cap from the tank and open the blead cock at the bottom rear of the radiator refill with the original factory Ethylene Glycol HD antifreeze, low silicate etc. (if the antifreeze was green that was drained NOT Pink or Red) according to Cummins specifications and add one pint of DC4 for every 2 gal mixture antifreeze and distilled water (A lot cheaper than the pre mix), on the filter the shut off valve is bad about twisting off so remove the filter after draining, if you cant get it with a filter wrench try a strap wrench or a pipe wrench replace the filter with a 4 unit filter.
When I did my engine coolant change I think it held about 8 or 9 gal and after I ran it to warm up and it cooled down it took another 2 gal.

dashdriver · 11-07-2009, 10:21 AM

Thanks for the reply...I have an ISM but it appears the coolant system capacity is similar. I think I have figured it out. I put about 9.5 gallons back in.

Ray

Steve Ownby · 11-07-2009, 01:39 PM

Hi Ray,

If you wouldn't mind, please post a description of how you proceeded. Did you have to take off a hose or other wise open the system to add to total amount of coolant. Also did you do the flush that you originally intended?

At some point I will do what you did & I want to flush so I can replace with an OAT type coolant.

Thanks,
Steve O

walt2137 · 11-07-2009, 02:35 PM

What coach and engine Steve?

Steve Ownby · 11-07-2009, 08:23 PM

Hi Walt & Will,

2003 Monaco Signature w/ ISM

Steve O

dashdriver · 11-08-2009, 01:14 AM

Hey Steve,

I just used the radiator drain cock (fully open) to drain mine. I drained it cold and then ran the engine up to temp (about 86-87C on mine) and drained it again.

I then flushed it with distilled water by pouring it into the overflow tank but did not use my Fleetguard Restore as I wasn't seeing anything suspicious in the old coolant. I even put a test strip in the old coolant draining out and it was still showing to be in pretty good shape. After flushing twice with distilled, I put in Fleetguard ES Compleat, ran it up to temp again and then topped it off. I cracked the drain cock open a hair after I was done, just to make sure the new stuff had made it into the radiator and it came out blue just like it went in, so I was happy my thermostat seemed to be working.

When running the engine up I had the dash heater on full hot with a low fan setting to ensure the dash heat loop got taken care of.

As for getting the engine up to temp, I ran it at low idle for several minutes until I saw the needle start to move, then used the cruise control to set it at high idle at about 1200 RPM per Cummins recommendation. Took a while to come up to temp, but it made it.

I still need to wash the outside of the radiator as the bottom 1/4 of the grill is showing some dirt on it.

Ray

P.S. If you want a more complete draining of the old fluid, you could disconnect a hose or two and let fluid come out of there, but I didn't do that this time. I just flushed it twice with water and it did the same thing, hardly any old coolant coming out towards the end of the second flush.