I've read Brett W.'s coolant change procedure and the Beamalarm coolant change process. On Beamalarm.com I read some radiators have a drain cock and on others you need to take off the lower radiator hose. I'm assuming that's the lower hose on the radiator?
Also, another stupid newbie question, where do you pour in the new coolant? :-[
Does the ISM 450 need bleeding after filling?
Dumb questions like these are when I'm glad this is a no-flame zone forum. :D
Mark
Pour it in the coolant reservoir. The bottom hose fills through the engine block to the radiator. Then fill overflow and go. Add coolant to the overflow when needed to finish topping off. Mine had the petcock.
I have an older model than yours, so it may be different, but my radiator has a drain on the bottom front. It's about 13 gal of coolant and took over an hour to drain all of it. I turned the dash temperature knob to hot to open that valve. Not sure if what was in heater and lines drained, but I think it did. I was replacing the water pump, and didn't try to flush and clean the system. Be sure to use an antifreeze approved for your engine. My engine did not require bleeding, yours may, but probably not.
On our C8.3 there is a drain petcock on the bottom of the radiator, and a shutoff valve on the coolant filter mount. When we had our coolant changed over to ELC, they pulled the filter off but left the shutoff valve open - said that helps the engine drain faster. Then they filled engine with water, closed the filter shutoff valve, and ran the engine for a while. Opened the filter shutoff valve and drained the water. Did that 3 times. After the last flush they filled engine with correct quantity of ES Compleat OAT + water and installed a new "blank" coolant filter (left the shutoff valve open, of course). The next couple times we drove the coach I had to add a little 50/50 mix to the overflow tank. After that the level stabilized and has never changed since.
Jerry the 8.3's like ours also have a petcock on the engine oil cooler on the side by the oil filter,have to crawl under the coach to get to it.
Woo hoo! Found a petcock on the radiator. Life just got a little simpler. Right hand thread, yes?
Yup it should be.
While you have the coolant out, pull the tank and take care of the rust behind it, and change out the thermostat,,(Our coach had a recall on the thermostat (cocks & sticks)
And really give the hoses a good inspection, I had one replaced @ MOT (leaking/ split inside) and just did replace 6 more hoses due to age.. (4 had small splits inside)
And, even staying with the same coolant, would do one tap water rise and then final rinse with distilled water. Even better if you take loose one of the hoses that goes to the water heater and dash heater and use either tap water or air to blow the old coolant out of those circuits.
When I changed coolant I changed all the hoses. Bought some at Rock Auto and others at internet truck stores. Not that much money when you figure the price of the coolant and what a ruptured hose would cost.
Went another step and painted the 2" piping,got the hoses at Silicone Hose | Silicone Vacuum Hose | Silicone Radiator Hose - Flex... (https://www.siliconehose.com) ,and don't forget new hose clamps.