Trouble Replacing Coolant

[Chevy29]

Can anyone advise me of the method of installing replacement coolant in my NT DID Pajero with rear heater.
I have flushed the cooling system twice now and on each occasion I have not been able to insert greater than 6-7 litres of fluid.
I have placed the rear of the vehicle on ramps to drain the rear heater after I have opened the heater pipes under the vehicle and drained the engine block. I accept that I may not get all the old fluid out (hence the flushing) but replacing only 6-7 litres into the system I think is a bit low.
I have had the front of the car on ramps hopefully to remove any airlocks when refilling the system.
I have checked other threads on the forum but none indicate any issues with refilling the system so I think I may be doing something wrong.


Any advise would be greatly appreciated.

[Keithyv]

I don’t think you are doing anything wrong. It just does not all come out (there’s always an amount in the engine etc.)

[spot01]

My mechanic tells me they only use about that amount when refilling, as a few litres remains in the system. Your quantity sounds about right.

[boritz]

Early this year I changed the coolant in my NW - managed to drain about 9 litres.

Drained each point into a large storage box and decanted into a bucket to measure with the bucket graduations.

Drain points were:
1. Radiator drain tap
2. Engine block drain plug (driver side lower front of block) - 12mm bolt/plug
3. Heater hose under driver seat floor pan.
4. Radiator expansion tank - lift out.

I also disconnected the heater hoses at the rear heater/AC but nothing came out after draining from the above points so I won't bother with this core in future.
[Edit] The vehicle was level while draining all of the above so I presume that the rear heater drained via 3. heater hoses under the driver seat floor pan [end-edit].

Flushed the system by inserting an irrigation T-piece in the heater hose under the driver seat and manipulated the block and radiator drains.

[Chevy29]

Thanks for the advise. While I expected some fluid to remain in the system I did not expect it to be 3-4 litres and that was my concern.
Thanks again for the reassurance.
Regards

[_jp_]

Also, if you have a rear heater, this can hold a bit. I removed the pipes under the car at the rear during the last flush to get as much out as I could.

[Larppanen]

Is there any point to drain as much coolant out as possible, then fill with plain water and warm engine up, then drain and fill again with plain water and warm up until clear water drains out and then fill with new coolant mix?

Maybe this way it is possible to get all old coolant out from system?

I need to change coolant soon, so just wondering..

[DaveH]

when flushing the cooling system or refilling please remember NEVER USE TAP WATER always used demineralised water even with anti freeze etc. Tap water has stuff in it that will eat the alloy components away from the inside so you won't see the corrosion till it is too late.

[Chevy29]

Thanks for all your advise/comments. I've not been on the forum for a while, hence my late response but I did manage to get about 9.5 litres into the vehicle (including the reservoir to the full line). I did flush the system using tank water as we do not have town water and installed the coolant mixed with demineralised water. However to get the coolant into the system involved putting the front of the vehicle on ramps, pouring in the coolant mix, running the engine up to 60 degrees while adding more of the mix and then taking the vehicle for a short drive (2 k's, temperature rose to 90 degrees by the time I got home), left the vehicle for a couple of hours to cool down and then repeated the procedure all over again.
This procedure was was repeated twice more and then job done!
It was not a simple matter of adding the coolant to the engine in one operation.

- Darryl

[crispus]

A little late, but there is also the EGR cooler (1582A089)...