4 replies to this topic

[terry tibbs]

Morning all

I had a go at changing the coolant in my ‘92 Cooper SPI over the weekend. Using the drain plug at the front of the radiator I dropped the mess that was the original coolant, ran the hose through the radiator until it ran clear and also took the short top hose off and ran water through the thermostat again till it ran clear. I then topped it up with water and added a solution to help clean any gunk out.

When filling it on took a maximum of 2 litres of water to refill the system, the Haynes manual said 3.5litres.

I ran the car for 30mins and drained away the solution, rinsing the system out the same way I had previously. I refilled with coolant and water but again only needed a maximum of 2 litres. I ran the car to check there were no air locks and then left it overnight. On checking the following morning the level of fluid hadn’t dropped and didn’t need topping up.

Is there something I have missed? Could there be a blockage somewhere else. I’m concerned it’s only take half the prescribed amount to refill the system and don’t want to do any damage.

[nicklouse]

There would have been coolant in the engine. And the blower unit.

[terry tibbs]

That’s understandable, but how do they empty if not from the drain plug? Should I have taken the thermostat out completely and flushed through? Would that have forced the remainder out?

Apologies, I’m a novice at this and taking each thing a step at a time, just need to get my knowledge and confidence up!!

[sonscar]

The thermostat effectively closes off the block and may cause a vacuum.I like to take off a heater hose and blast water down into the block.If you have good lungs you can blow a lot of water out of the pipe also,compressed air might be safer.Steve..

[MatthewsDad]

Removing the lower radiator should drain more coolant. I'd also include direct flushing of the inlet manifold area with a hose pipe as this really clogs up.