Changing over to RMI 25

[TRBON8R]

I just drained my radiator and put in new upper and lower hoses. I'm going to be refilling with RMI 25 and distilled water.

First I want to make sure I get the rest of the old coolant out of the heater core and the rest of the system. I was planning on refilling the car with regular tap water, driving it for a mile or so and then draining. I thought I would do this two times before switching over to the distilled water and RMI 25. Some people say you can hurt a water pump real fast by driving on just plain water with no additive. Since I'd only be doing it for a mile or so, could it actually hurt anything? Almost forgot, do I really need to empty out the first dose of RMI as the directions say since my radiator is only 6 months old, or can I just fill up and be done with it?

 

[Kevin Turch]

All you really have to do to completly drain it is, fill it, run the car for a bit, drain it, and repeat 4 times
then fill with rmi and distilled, doing it 3-4 times assures its completly flushed out. No need to drive it.
HTH
Kevin

 

[Nick Micale]

Originally posted by TRBON8R
....First I want to make sure I get the rest of the old coolant out of the heater core and the rest of the system. I was planning on refilling the car with regular tap water, driving it for a mile or so and then draining. I thought I would do this two times before switching over to the distilled water and RMI 25........do I really need to empty out the first dose of RMI as the directions say since my radiator is only 6 months old, or can I just fill up and be done with it?

You can use water for a mile or 2 without any problem. If you have flushed the system like you said, put in water and RMI then drive it 4-500 miles and flush again. Should be good for 6 months then.

It is a good idea to remove both hoses from the heater core and flush it with a garden hose to get out the residual junk. Your radiator may be clean and new, but the block and heater core has 15 years of build-up in there still. RMI will eventially clean up the system.

 

[TRBON8R]

Thanks Kevin and Nick!!