I've got '00 Diamante with 70Kml. Is it worth to pay $80 to dealer to do coolant flush? In my mind, this is fairily easy procedure. I have no problems now, just figure it's time to change it based on miles and year. A few questions. Where is drain valve located? Just draining the old one and adding a new antifreeze sufficent enough? Any special procedures? Coolant from Mitsubishi is pretty expensive, can I use some generic brand? Is 50/50 mix OK? What kind of water I should use? Anything else I should consider? Thank you.

 

Well when the dealer does a "Coolant Flush" they hook you coolant system to this machine that pumps about 2 gallons of new coolant and conditioner through to clean it all out. What color is you coolant now? If it is still green then you really dont need the flush. If your going to just drain it and put new stuff in, which is fine, the petcock is located at the bottom of the radiator usually opposite the feed hose. Yes any 50/50 mix coolant is fine. Just buy the coolant that is already 50/50, save you time and money.

 

Hey I would recommend that you not use the petcock located on the underside of ur radiator. I would suggest that you just disconnect the lower radiator hose and let it drain out that way. if u use the petcock there is the possibility you have some junk in your radiator and it might not come out that way. Oh take off ur cap to it drains faster

 

I agree! The quicker flow of coolant will also help remove debris that may be in the engine block.

Also, use caution when thinking about flushing. The dealers and service shops promote a 'power flush' that's great for removing the debris and corrosion. Only problem is that in a lot of cases, THAT CORROSION is holding up leaks in water pumps, heaters and frost plugs.

Having spent countless years in the cooling system business, I would strongly suggest the 'off the shelf' type Cooling System Flush chemical that you add to the cooling system, and then let the system run for a while. Then you drain and refill.

With respect to mixtures, you should follow the coolant manufacturers instructions, but 50/50 is about right.

Also be sure you fill the cooling system properly. Although this post (in the link) is about refilling the cooling system because of leaks, it also applies here. You should read this information on refilling your cooling system.

Hope this helps!