Coolant Filling Tool Alternative To Cylinder 4520-T And 4222-T

[paul.h]

In the Haynes manuals and the Citroen service box procedures it is recommended to use special tools 4520-T and 4222-T when filling the coolant since the max coolant level in the expansion tank is below the air bleed screws. All the tools do is raise the level of the coolant above the bleed screws so the air can be pushed out.

 

You can make a simple tool for less than £5 using an old expansion tank cap (or a new one for around £4), about 12 inches of basin waste pipe 32 mm diameter (1.25 inches) and the triangular section rubber seal from a 32 mm fitting such as a basin U bend or pipe connector. 2 m of the push fit waste pipe is £1.29 from Wickes. To make the tool prise out the tank cap internal valve then cut out a hole in the cap so the 32 mm pipe can just fit through it (drilling/Stanley knife/filing work). Push the pipe through the cap and fit the seal on the pipe.

 

To use it, fill the coolant in the expansion tank to just below the max level, fit the pipe in the tank so it extends in to the coolant to just below the max level, push the seal down to the tank neck and then tighten the cap on the tank to give an air tight seal. Add coolant in the pipe to about 2/3 of its height (use a funnel to avoid spilling) - the pipe will fill but there will be an air pocket in the tank so the tank does not fill up. Then open/close the bleed screws in turn until any air is displaced. If needed more coolant can be added in the pipe. Once the air is out, undo the cap which will release a slight bit of air pressure and the coolant in the pipe will run in to the expansion tank and the pipe can be removed without any spillage - the tank level should be at max. Then fit the normal cap to the expansion tank, check for any leaks and then run the engine. This diy tool worked well when I replaced the thermostat housing on our C5.