Thread: Coolant flush P38.

Red VS Green Coolant again!!!

cheers

There is a drain plug in the bottom of the Rad. Drain from here and also remove the bottom hose from the Thermostat ( the cream coloured thing with several hoses joined on ) engine side, you will get soaked. I would use a system flush first then remove the top hose and give a serious flush out with water both into the block and into the top of the Rad with the drain out and thermostat disconnected . When refilling get the front of the car up high and after filling let it cool a couple of times with the cap off and recheck the level. The coolant seems to get drawn into any air pockets.

Originally Posted by PeterH

I've been having a search around the forum for this topic, but couldn't find a clear answer.
Can anyone give me advice on the best way to flush out the coolant on my P38 Thor engine?
Never tackled that job before on a P38, always best to ask other peoples experiences first methinks!
Also there is a notice on the expansion tank to use OAT + H20.
Any suggetions on good quailty OAT coolants suitable for a Thor?
Thanks, Pete.

If you arent going to the snow every day use any corrosion inhibitor that does not contain glycol!!!!

Thanks for the replies everyone.
Wayneg when you say use a system flush, do you mean a type of cooling system cleaning additive to run through the cooling system and then flush that out?
Sorry to ask silly questions, just clarifying.
Sounds like a job to do on a warm day if I'll be getting soaked!
Cheers, Pete.

Use any one of the many offerings of system flush which you add to the system and run for a specified length of time Follow the instructions as the stuff is caustic so cant be left in for to long. Dont put it into the expansion tank, drain some coolant from the rad, add via the top hose and top up into the expansion tank with the coolant you drained off. When you remove the hose from the Thermostat the water will just gush out an no doubt all down your arm and upper body unless you are quick. You might also think about changing the hose clamps to worm drive ones as unless you have the correct tool are a bit of a pig to remove when there`s little space. There are reports of them not holding when the pressure is high. I have had no problems with my clamps but I hate the design.
Whilst there check the hose from the Rad to expansion tank is clear and maybe extend the overflow from the expansion tank so it runs to the floor

If you've got the bottom hoses off and plan on changing the colour of the coolant your using, make sure you stick a hose up the water pump and through your heater core too (remove one of your heater hoses to make this easier). Flush forward, backward, up, down and side to side! Get it wet!

And get worm drive clamps. I had two of those dicky spring type ones fail on me. Luckily i caught it in time! Just replace all of them if you've got the time and funds to do so! Save getting caught out in the middle of the bush!

Much fun!
Keithy

meant to mention: when refilling- once you have reconnected the hoses below, jack up the front wheels about 100mm. Refill slowly through the top radiator hose. Having the front slightly raised will ensure that there is minimal chance of air being trapped in the bowels of the engine...
cheers

Excellent information all round there, thanks for the great advice everyone.
The thing I most appreciate about this forum is the tips you get that are NOT in the workshop manual.
Can't beat hands on experience!
Cheers, Pete.