Coolant Flushing

[306Puggy]

Since I'm doing my heater matrix I thought I might as well renew the coolant as well since it has been a few years since last time. Last time I did it I uncliped the small hose above the bottom hose, removed the thermostat and just drained it then flushed it through, but this time I want to do a more thorough job by taking off the bottom hose and flushing it that way. Obviously you need to get the radiator free to access the bottom hose but I've never taken it off before, is it a front end off job or...? Also do I need to remove the thermostat or will the water find a way around it?

[Daniel306]

Its there not a drain plug on the bottom of your radiator? Just take the slam panel of and it can be lifted out

and to flush it out i normally drain it and fill it up with clean water then run the engine untill its hot, and repeat untill the drained water is clean

[306Puggy]

The Haynes manual actually mentioned the drain plug but on my radiator it is blanked off. I was planning to flush it through with the hose pipe.

[ozonehostile]

You should be able to disconnect the bottom hose from underneath the car if your hand will fit, needlenose mole grips are incredibly useful for releasing the clip holding the hose on. If you want to thourougly flush out the system take the thermostat out. the best way to flush the coolant is get a hosepipe stuck into the top of the rad, disconnect the hose and thermostat, start the car so that it pumps out its own coolant and just leave the hosepipe running until the water coming out runs clear. Make sure you refill the rad with a strong antifreeze mix for the winter

[306Puggy]

Heh, this whole this is made more complicated due to the fact that my radiator has the bayonet type fitting which needs unclipping and twisting round to undo it. Which is why I'm having problems trying to figure out how to go about it. That flushing method sounds good, I'm always afraid of popping the head gasket when it comes to coolant related things though! Maybe I'll give it a whirl.

[ozonehostile]

Heh, this whole this is made more complicated due to the fact that my radiator has the bayonet type fitting which needs unclipping and twisting round to undo it. Which is why I'm having problems trying to figure out how to go about it. That flushing method sounds good, I'm always afraid of popping the head gasket when it comes to coolant related things though! Maybe I'll give it a whirl.

have you looked at other coolant hoses that you could unclip other than the bayonet on the rad?
there are other hoses on the bottom of the block which are far easier to access

[306Puggy]

Yeah last time I undid the small one above from the bottom hose but I want to get all of the rust silt out from the bottom of the rad!

[Daniel306]

Take the slam panel off and its easy to remove the rad. its better to be able to cope the crap out the it and put the hose in the top pipe

[306Puggy]

As it happens I decided to flush it through using the running engine method instead of dropping the old stuff and refilling it. But instead of removing the thermostat I just ran the lump upto temperature because I didn't have a replacement gasket for the thermostat housing, which last time I had to do up using instant gasket. It worked quite well, although not as well as taking the thermostat out obviously as it restricted the flow, but after a couple of bucket fulls it was running fairly clear. The only thing I am not sure about this method is that the water from the hosepipe is cold and the engine will be hot after a few minutes running which some people might say would do the headgasket in.

[Piggy]

dish washer tablets work a treat

[ozonehostile]

As it happens I decided to flush it through using the running engine method instead of dropping the old stuff and refilling it. But instead of removing the thermostat I just ran the lump upto temperature because I didn't have a replacement gasket for the thermostat housing, which last time I had to do up using instant gasket. It worked quite well, although not as well as taking the thermostat out obviously as it restricted the flow, but after a couple of bucket fulls it was running fairly clear. The only thing I am not sure about this method is that the water from the hosepipe is cold and the engine will be hot after a few minutes running which some people might say would do the headgasket in.

It wouldnt really affect it using cold water unless the engine was red hot, just flushing the coolant out is fine