flushing cooling system

[nkx]

i bought a new 2 row radiator, so i figure it would be best if flush out all the old coolant and accumulated crap as a preventative measure before i install the new rad.

 

what ive been doing is draining the radiator, filling it back up with distilled water, drive the car for 10 mins or so. park it, wait for it to cool, drain rad, refill with water, etc.

 

is there an easier/faster/better way to do this? should i bother with the drain plugs on the bottom of the block?

[mikeshoup]

Yup, open up the petcock on the radiator and pull the drain plugs on the bottom of the heads. Run water through it until the water turns from green to clear.

[nkx]

well i was able to get at the pass. side drain. got a face full of coolant too.

 

am i supposed to have the car running while im pouring water back in?

[mikeshoup]

No. Just stick the hose in the inlet to the radiator, and let it flow until what's coming out turns clear.

 

When you're done, let everything finish draining, hopefully emptying the system. Refill with 50/50.

 

P.S., yeah, after the first time removing the drain plug, you learn to not lay underneath the car, and twist that bolt with as long as a reach as you can get. First time I drained the XT's coolant, It sprayed out everywhere.

[dave valiant]

When I do a flush I remove the radiator cap and one of the heater hoses. Then I put the garen hose on the heater hose so it goes through the heater core and it all runs out the radiator. I will do that until it runs clear then start the engine and run it for a few seconds, this will push out some water so all you have to do is add a gallon of anti freeze to the system. Well add the antifreeze after you reconnect the heater hose and then burp the cooling system.

[mikeshoup]

If you add the antifreeze seperate from the water, add 3/4 gallon. The system holds 1.5 gallons total.

[bgd73]

Is just water enough? I found some slime in my system as well as the dreaded miracle sealers that clog radiator. After new radiator, I don't want any cruds in there. Is the bottles I found at the part store labeled for system coolant flush nothing good? I would just assume keep a garden hose on it until it was cleared out, but would take extra step if the flush fluid works.. anybody used it? The last time I used garden hose it completely clogged a few more rows on the radiator-- I guess 15 lbs water pressure is a bit much , after seeing the release pressure on radiator cap (0.9?) :-\

[mikeshoup]

15lbs isn't a bit much pressure. The radiator cap holds in 13lbs, and I know Phil/KBD is running 16 lbs in his RX.

 

Flush junk, I've never used. I can't comment on how well it does or doesn't work.

[exister99]

Or, for just a few bucks you can pic up a flush kit that splices into your heater hose. You tap a garden hose into it and run the engine until clear water is gushing out of the top of the radiator. Works great and beats the heck out of stressing the threads in the cylinder head every time you want to flush your cooling system.