Best way to flush an AX cooling system?

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ItDontGo
Posts: 253
Joined: 20 May 2004, 04:58
Location: United Kingdom
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Best way to flush an AX cooling system?

Post by ItDontGo »

I was horrified to see what came out of my cooling system when I topped up the anti-freeze. I was even more horrified when a quick flush cured the funny noise coming from my cambelt cover. The poor little water pump must have had its work cut out.
Anyway I think I ought to give it a proper flush and was wondering what would be the best way to go about it. Please bear in mind it is cold outside, our garage is full and I want to pull as little of the little bugger as is possible.
I may also change the cambelt, which would be prudent considering I have had a cambelt failure every two years on average, but I never know what is a decent tension. It always seems too tight or too loose.
[8] Which mood does this face depict?
martyhopkirk

Post by martyhopkirk »

Flush the rad by disconnecting top & bottom hoses (with much swearing and bruising of knuckles) then use garden hose and tap with reasonable pressure to back flush (bottom to top). You can flush top to bottom (oh remove the expansion hose too) but i always find more crud comes out by back flushing. (sometims much easier if you remove the rad to do this).
Flush block through by removing thermostat - insert garden hose into top pipe from radiator and then let her rip. Again till nice clean water comes out.
Re fit thermostat.
Reattach hoses.
Open all bleed screws
Fill from expansion tank using a headder tank to avoid air locks. ( I use half of a 10L cleansing fluid container, but you could fashion something similar out of a large bleach bottle with the bottom cut out - it has to be higher than the top hoses of the Rad).
As water/antifreeze mix starts to flow out of the bleed screws close them off (once bubble free coolant is escaping) bottom most first. Thne so on upwards. The final three are:
Radiator, Thermostat, heater hose.
(header tank still in place with a good 400ml of fluid in it)
Start engine - let it idle till fan kicks in.
Remove headder tank ***HOT FLUID*** dont burn yourself
Refit headder cap.
Easy!
Handy hint - do this on a neighbours drive as the orange stain resulting will not shift off concrete.
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