Wait until the engine is cold before starting this procedure. Do not allow antifreeze to come in contact with your skin, or with the painted surfaces of the vehicle. Rinse off spills immediately with plenty of water. Never leave antifreeze lying around in an open container, or in a puddle in the driveway or garage floor. Children and pets are attracted by its sweet smell, but antifreeze is fatal if ingested. Refer to the ‘Antifreeze mixture’ sub-Section below before proceeding.
Cooling system draining
To drain the cooling system, first cover the expansion tank cap with a wad of rag, and slowly turn the cap anti-clockwise to relieve the pressure in the cooling system (a hissing sound will normally be heard). Wait until any pressure remaining in the system is released, then continue to turn the cap until it can be removed.
Position a suitable container beneath the radiator. On early models (where a drain screw is fitted to the bottom, left-hand corner of radiator) unscrew the drain screw and washer, and allow the coolant to drain into the container. On later models (were no drain screw is fitted), release the hose clip, and ease the hose from the radiator stub. If the hose joint has not been disturbed for some time, it will be necessary to carefully manipulate the hose to break the joint. Allow the coolant to drain into the container. On TD5 models, slacken the clips and disconnect the lower hose from the thermostat.
To fully drain the system, on non-TD5 engines, also slacken and remove the coolant drain plug from the left-hand side of the cylinder block, and allow any residual coolant to drain from the block. On TD5 engines, there is a drain plug fitted to the right-hand side of the block
, but the alternator must be removed before access can be gained. When the flow of coolant has stopped, wipe clean the threads of the drain plug and block. Where the plug was fitted with a sealing washer, fit a new sealing washer. Where no washer was fitted, apply a smear of suitable sealant to the drain plug threads. Refit the drain plug to the block, and tighten it securely.
On TD5 engines, the cylinder block drain plug (arrowed) can only be accessed after removal of the alternator
If the coolant has been drained for a reason other than renewal, then provided it is clean and less than two years old, it can be re-used.
Cooling system flushing
If coolant renewal has been neglected, or if the antifreeze mixture has become diluted, then in time, the cooling system may gradually lose efficiency, as the coolant passages become restricted due to rust, scale deposits, and other sediment. The cooling system efficiency can be restored by flushing the system clean.
The radiator should be flushed independently of the engine, to avoid unnecessary contamination.
To flush the radiator, disconnect the top hose at the radiator, then insert a garden hose into the radiator top inlet. Direct a flow of clean water through the radiator, and continue flushing until clean water emerges from the radiator bottom outlet (the bottom radiator hose should have been disconnected to drain the system). If after a reasonable period, the water still does not run clear, the radiator can be flushed with a good proprietary cleaning agent. It is important that the cleaning agent manufacturer’s instructions are followed carefully. If the contamination is particularly bad, insert the hose in the radiator bottom outlet, and flush the radiator in reverse (reverse-flushing).
Remove the thermostat, then temporarily refit the thermostat cover.
On completion of flushing, refit the thermostat, and reconnect the hoses.
Top-up the expansion tank to the correct level, then refit the expansion tank cap. On TD5 models, also refit the intercooler hose.
With the radiator top and bottom hoses disconnected from the radiator, insert a hose into the radiator bottom hose. Direct a clean flow of water through the engine, and continue flushing until clean water emerges from the radiator top hose.
Cooling system filling
Before attempting to fill the cooling system, make sure that all hoses and clips are in good condition, and that the clips are tight. Note that an antifreeze mixture must be used all year round, to prevent corrosion of the alloy engine components.
On early models, refit the drain plug and sealing washer to the radiator, and tighten it securely. On later models, reconnect the bottom hose, and securely tighten its retaining clip.
On 300 TDi engines, unscrew the filler cap from the top of the thermostat housing, and recover the sealing ring
. On earlier models, unscrew the filler cap (where fitted) from the top of the radiator. Recover the cap sealing ring (where fitted); renew it if it shows signs of damage or deterioration. On TD5 models, slacken the bleed screw in the radiator top hose and fuel cooler hose
On 300 TDi engines, the filler cap (arrowed) is situated on the top of the thermostat housing
On TD5 engines, open the bleed screw in the radiator top hose (arrowed) . . .
. . . and in the fuel cooler hose on the right-hand side of the engine (arrowed)
Set the cabin heater controls to maximum heat.
Fill the system by slowly pouring the coolant into the filler hole or, where no filler hole is fitted, into the expansion tank (as applicable) to prevent airlocks from forming.
| 10J and 12J engines
| 19J, 200 TDi and 300 TDi engines
| TD5 engines
| All except TD5 engines
||Ethylene glycol-based antifreeze
| TD5 engines
||Ethylene glycol-based antifreeze with OAT (Organic Acid Technology) corrosion inhibitors
When coolant free of air bubbles emerges from the filler (where fitted), refit the seal and filler cap, and tighten it securely. On TD5 models, when air-free coolant emerges, tighten the bleed screw in the radiator top hose and fuel cooler hose.
Start the engine, run it until it reaches normal operating temperature, then stop the engine and allow it to cool.
Check for leaks, particularly around disturbed components. Check the coolant level in the expansion tank, and top-up if necessary. Note that the system must be cold before an accurate level is indicated in the expansion tank. If the expansion tank cap is removed while the engine is still warm, cover the cap with a thick cloth. Unscrew the cap slowly, to gradually relieve the system pressure (a hissing sound will normally be heard). Wait until any pressure remaining in the system is released, then continue to turn the cap until it can be removed.
Always use an ethylene-glycol based antifreeze which is suitable for use in mixed-metal cooling systems.
On TD5 models, only antifreeze with OAT (Organic Acid Technology) corrosion inhibitors must be used. Do not mix this with any other type of antifreeze.
Before adding antifreeze, the cooling system should be completely drained, preferably flushed, and all hoses and clips checked for condition and security.
After filling with antifreeze, a label should be attached to the radiator or expansion tank, stating the type and concentration of antifreeze used, and the date installed. Any subsequent topping-up should be made with the same type and concentration of antifreeze.
Do not use engine antifreeze in the windscreen/tailgate washer system, as it will cause damage to the vehicle paintwork. A screenwash should be added to the washer system, in the quantities recommended on the bottle.