So I decided to do a full coolant change on my Jeep since I didn't know what coolant was in it from the previous owner or how long since it was last changed.
Also it had a red coolant and I prefer green coolants as they show up leaks much better.
So I bought 6lts of Nulon Premium green from SCA on special a few weeks back.
According to the US 2007 handbook pdf the CRD uses 13.2lts total.
(Can anyone with an AU handbook confirm this? Sadly mine didn't come with books..)
So I calculated that 5lts of concentrate plus 4.5lts of 33% premix (which I already had) and 3.5lts of water gets me pretty spot on 50/50 mix.
First step, drain the radiator. The drain plug is very hard to turn by hand, so use a pair of bull nose pliers but be careful not to snap the plastic off.
Draining the radiator only gets 8lts out. A little bit more when you disconnect the lower radiator hose. So that leaves around 5lts still in the block.
With both radiator hoses disconnected at the radiator, I reverse and forward flushed the radiator several times just with hose pressure.
I then flushed out the coolant tank several times, filling it and letting it drain.
Now how to flush the block. The correct way would be to remove the thermostat and flush from the top down. But removing the thermostat and thermostat housing looked to be too much work lol.
So I tried reverse flushing from the bottom radiator hose until the coolant tank was full, then letting it drain. I did this several times and amazingly this seemed to suck most of the red coolant out of the block.
Next I connected everything back up, filled it with tap water, ran the engine for a minute with the heater on just to circulate what was left and then drained it all again. At this point there was very little red in what was drained, but I forward and reverse flushed the radiator and coolant bottle again to get as much out as possible.
Next, drain all that out, and fill it up with distilled water ($5 for 5lts from Bunnings).
Drove it for half an hour with the heater core open, then left it overnight to fully cool down.
Drained it all out again, no sign of any red now. Filled it a second time with distilled water and repeat above.
I figure that's a pretty decent flush. No sign of any red in the water drained out after the second run with distilled water.
Final step. Drain it out, fill it with the 6lts of concentrate, then top up with the 33% premix until full. By my calculation with the approx 5lts water in the block this works out pretty close to the desired 50/50 mix.
All done!
And looks like the coolant system was in pretty good condition. The red coolant I drained out was very clean, and all the fittings on the hoses I disconnected were all in excellent condition with no signs of corrosion or damage. So looks like my engine has been well maintained
WH CRD Coolant Change and Flush
