i need help cleaning out my cooling system

[stillhi33]

I've got a mercrusier 170hp/470 1985 I got it started but notice there was rust chunks resting at the bottom of the coolant cap and was wondering if there was a drain plug at the bottom of the big black tube that hooks to the top connecting to coolant container i was told by an old friend that i could take a garden hose to the coolant resivor and flush everything out but what do i have to unplug to get all that stuff out??? thank you for reading

 

[jerryjerry05]

Re: i need help cleaning out my cooling system

Thats the heat exchanger.You have drain plugs on the bottom of it.There is a drain plug on the side of the motor above the starter. Start flushing and replace the coolant with a good quality antifreeze and waterpump lube.Jerry

 

[stillhi33]

Re: i need help cleaning out my cooling system

thanks petty officer 1 st class what is a waterpump lube and where cn i get it this is sort of a project bot i had for a while like 5 yrs but whos counting..lol..but i replace the waterpump about 3 yrs ago an that was one of th reason i wanted to flush everything out it had broken pieces of the rubber or plastic blades tha broke off in there well any help is awsome thanks ahead

 

[bhammer]

Re: i need help cleaning out my cooling system

Those rubber blades are from the lower unit impeller and it should be checked/replaces.

You can take off both end caps of the heat exchanger to expose the raw water side. The part that the cap secures too, is not the heat exchanger though. That is located on the port side and is the long cylinder. It will be either 3" or 4" dia depending on model. The antifreeze holder that has the cap, if it is rusted or has rust, you may want to simply remove it and wash it out.

When I had my 470, I used standard auto type flush and fill kits to flush it out. Then just filled with standard antifreeze, that was safe for the enviro...

 

[stillhi33]

Re: i need help cleaning out my cooling system

Thanks everyone for your help and getting my boat on the water again