Thread: Cooling system flush

No point in just flushing it. Pull it out and do it properly.

Originally Posted by Grumbles

No point in just flushing it. Pull it out and do it properly.

I know what you're saying grumbles, but at this point I can't spend anymore time or money on it. The running temp is fine. I just want to get some coolant in there but don't want to add it too a dirty system. If radiator is blocked I'll look at that later. Plan is to use a coolant flush (nulon) for now.

Pete

Originally Posted by discopete

Plan is to use a coolant flush (nulon) for now.

Pete

I used Nulon rad flush after a workshop got a small amount of engine oil into the cooling system after replacing a head on my Benz truck I ended up using four bottles but it did the trick. Read the instructions on the bottle and you should be fine.
PS: My new years resolution - phone Super(not so)cheap first for a price and then buy from them last!

Originally Posted by isuzubob

I used Nulon rad flush after a workshop got a small amount of engine oil into the cooling system after replacing a head on my Benz truck I ended up using four bottles but it did the trick. Read the instructions on the bottle and you should be fine.
PS: My new years resolution - phone Super(not so)cheap first for a price and then buy from them last!

Thanks Isuzubob. The instructions seem simple enough. But to flush system properly after use does the thermostat need to be removed or can I flush through hoses either side of it.

Pete

Originally Posted by discopete

I know what you're saying grumbles, but at this point I can't spend anymore time or money on it. The running temp is fine. I just want to get some coolant in there but don't want to add it too a dirty system. If radiator is blocked I'll look at that later. Plan is to use a coolant flush (nulon) for now.

Pete

I agree pull it out and get it flushed. It cost me $70 to get my tanks removed, flushed, re-sealed and preassure tested. Money well spent. I also got one of those in-line Tefla radiator hose filters, but the jury is still out on that one, as the filter has stayed clean the whole time.

Andy

Originally Posted by discopete

But to flush system properly after use does the thermostat need to be removed or can I flush through hoses either side of it.

Pete

It's easy to remove the thermo, and this will deffinately help with flushing. The gasket will come out with the thermo, so you might get a bit of leakage out the housing, but probably not much.
An easy way to flush is remove the heater hoses at the heater end, point one of them down to the ground or extend it over the side into a container if you don't want to make too much mess. Stick the garden hose in the other one and turn the water on full. You can swap from one hose to the other if you want to flush it the opposite way as well. I use a trigger type fitting that fits neatly in the heater hose. It's easier using the heater hoses than the big rad hoses and it will blast the water through with a bit of pressure. Run the water until it's clean, and remember to give the heater core a quick flush too. Wack the thermo back in and fill 'er up.

Cheers, Murray

For what you are trying to do you need an alkali based flush (most are), particularly if using a conventional style coolant after.

Tectaloy make a good one called 'Mukowt'.

If anyone is going to use an OAT or HOAT coolant use an acid based flush after the alkali one. It will remove any rust and scale so the carboxylic inhibitor package isn't overloaded in the coolant.