Full coolant flush

[newkid]

Anyone know the best way to do this? Just bought the recommended red coolant and im sure the old stuff is green/blue, Hoping to sort the oil leak and swap the newer radiator in tomorrow. I know theres a drain bolt on back of the block but id rather try avoid using that.

[RattyMcClelland]

I suppose you could Jack the back of the car up with the front on the ground so the coolant heads to the front and maybe hose pipe through a rad hose.

[wurlycorner]

Coolant draining an h22 is jobby - what you get out is a very small percentage of what's in there total.
I've not actually found the drain plug myself yet.
Few options - drain, refill with water, run, drain, repeat until it looks clear, then refill with required concentration of coolant (not perfect).
Or drain, leave the drain open, flush through the rad from the top, then undo something like a heater hose, attach a hose pipe to that and flush it through until clear.

[NafemanNathan]

I always detach the hoses from the rad after draining it, then invert the top hose on the block, aim the bottom hose between the cross member and rad, remove the thermostat, but put the housing back on, and then flush it through with the garden hose via the inverted top rad hose.

[wurlycorner]

Yep. That's the best way. I just can't ever be bothered drokking around with thermostats (too many horrendous childhood memories of bolts always shearing off and needing to be drilled out from inaccessible areas of engines scared me for life )

[Sailor]

When your old rad's out, leave its hoses connected to the system. Then why not put a garden hose through it via one of the connections. If the replacement rad isn't new, it'll be worth reverse flushing that, too.

As to the coolant. the red stuff came out long after your 4G was built and the blue/green is more than adequate. Take the red bottle back to the shop and swap it out. If you can't do this (already opened the bottle, perhaps), don't worry too much. Once you've run a hose through as suggested, I can't imagine that there'll be enough of the old coolant left to cause a damaging amount of sludge. Even if it's true that the two versions don't go well together, the relative proportions will be heavily in favour of the new coolant.

[Sailor]

Yep. That's the best way. I just can't ever be bothered drokking around with thermostats

Ah, give me back the old days with a thermostat in a rad cap!

[Doggo]

Yep. That's the best way. I just can't ever be bothered drokking around with thermostats

Ah, give me back the old days with a thermostat in a rad cap!

So where do they put them these days?

[Sailor]

Yep. That's the best way. I just can't ever be bothered drokking around with thermostats

Ah, give me back the old days with a thermostat in a rad cap!

So where do they put them these days?

Normally somewhere near a knuckle-skinner.