Coolant change

gregk · 01-09-2011, 08:37 AM

Hello All,

Drained and flushed my 8.0 gen yesterday. Changed to Final Charge. All went well except that each time I drained the systen I only got about 3/4 of a gal out. I refilled with distilled water and ran it for one or two minutes to flush three times before all the green color was gone. Since I obviously had about 1/4 gal of water left in the system I refilled with 1/2 gal of the concentrate and then topped off with distilled water. Had planned to use 50-50 but since I could not get all the water out figured I better go with the concentrate to end up with the correct mix. I guess this was OK? Any comments.

Also, after the repeated drainings my over flow tank never drained. I finally siphoned the tank to get the green stuff out. Should the tank have drained when I drained the system??

Fixing to do the change on the ISL next. Will I have trouble getting this system to completely drain as well. Should I plan to go back with concentrate to mix with the water that does not drain out and maybe then fill the rest of the way with 50-50. Any idea of how much will remain in the system. The capacity is 9.75 gal. While flushing how long should I run the engine to warm up. Am I look for a particilar temp or just long enough to get thing mixed up well? One last thing, how many times should I plan on flushing. Was thinking of three flushing after the initial draining. Any comments.

Thanks in advance for any replys.

Diplomat Don · 01-09-2011, 05:26 PM

Put 7 gallons of 50/50 mix and then a gallon of concentrate. Top off the remainder with 50/50.

hardy1000 · 01-12-2011, 07:01 AM

GregK,

I flushed my Isl 400 and used Diplomat Don's thread used the 1 gallon of concetrate and the rest 50-50 mix as per his instructions. I can tell you it took me about 6 of 7 flushes to get the old coolant out and the best part of the day. Dont forget to run the heater to flush it also.

gregk · 01-13-2011, 06:21 AM

Del,
Did you flush with distilled water or water from your water system. My water system has very hard water.

H. Miller · 01-13-2011, 07:03 AM

Each "flush" needs to be run until the thermostat opens (180-185 deg.)
Also, we got an extra gallon out by removing BOTH the in and out hoses from the heater radiator and blowing the water out (low pressure). 70-80' of hose holds a lot of water!

Mike Canter · 01-13-2011, 07:23 AM

Would it not be a good practice to change the thermostats in both the generator and the motor when you change the coolant. It is highly recommended by Onan and Cummins and CAT. If you do that then first take out the thermostat and flush the system without it installed. Reinstall it prior to the final fill.

Also, don't forget there are drain plugs on the motor of the MH and the generator that should be removed to allow all the old coolant to come out. These drains should be opened in conjunction with the radiator drains.

gregk · 01-14-2011, 05:47 AM

Hal,

Were the In & Out heater hoses to the front easily found. Do they come off the block or elsewhere. I located the petcock off the block and will drain from there as well as the radiator.