I’ve owned a 2007 Partner (1.4 petrol) for seven years and replacing engine coolant has been a bit of a ‘fiddle’.
So I gave the matter some thought and this is the result.
Firstly I have to say this is an experiment with a cold engine. Further, I haven’t replaced coolant just carried out a major top due to coolant loss resulting from pressure cap failure.
However, this is the procedure.
Get hold of a used sealer tube, (the type that uses a ‘gun’ to force the sealant out) it should be 46mm inside diameter. The piston should then be 44mm inside diameter.
First remove the nozzle end – not much more than about 3mm -I used a hacksaw.
Remove as much of the old sealant as possible – from both sides of the piston.
Remove the piston from the tube – I bumped it out using the shaft of a hammer – taking care not to damage /distort it too much.
Drill two 6mm holes in the face of the piston and get hold of some flexible tubing 6 mm diameter by not less than 1.5 metres long. I cut the one end of the tube at an angle
Remove the cap from the coolant bottle and push the piston over the threads.
The piston I used was a tight push fit over the threads.
Thread the flexible tube (angled end first) through the sealer tube, and then through one of the holes in the piston.
Now push the sealer tube over the piston and route the flexible tube over the front of the vehicle.
Disconnect the small pipe from the air intake and remove the air filter.
Open the upper bleed point by removing the valve cap and keep topping up the coolant until it flows out.
When the fluid pours out, open the lower bleed point using a 5mm Allen key.
When fluid flows from the lower bleed point retighten it and, providing fluid is still pouring from the upper point, replace the bleed cap. Just remember to keep the tube topped up with coolant.
We now siphon out the excess coolant –using a siphon gadget if possible - into a container placed on the ground.
(If you don’t have a siphon gadget use the time honoured method. If you’re lucky you may avoid getting coolant into your mouth, if not rinse mouth ASAP).
If the tube is as low as it can go in the expansion bottle then the coolant level should end up just below the max mark.
Remove the tube and piston and replace the pressure cap.
I did all this with a cold engine, this method may or may not be 100% (if not, repeat with the engine hot, thermostat open) but at least no burnt fingers or mouth.
Good luck