UNDERBONNET SERVICING

1 CHECK COOLANT

The expansion tank’s transparent case makes it straightforward to check the level. Only release the pressure cap when the engine is cold. IVC uses a liquid analyser, which calculates the temperature at which the coolant can remain as a liquid. It’s always worthwhile testing the coolant.

2 RENEW COOLANT

If the coolant needs to be renewed – it should be changed every five years – there is a drain tap on the nearside bottom of the radiator, close to where a coolant hose is attached. The engine undertray will need to be taken off to access it (see Step 10). Refill the coolant via the expansion tank shown in Step 1.

3 WASHER FLUID

The windscreen washer fluid reservoir can be topped up via the filler neck located at the nearside rear of the engine bay. Lift up the blue flap, extract the filter and make sure it’s clean. The strength and freezing point of the fluid can be checked if necessary. Top up with diluted screenwash.

4 REMOVE OIL FILTER

The oil filter can be undone and removed using a 32mm socket, extension bar and ratchet. Once it has been unscrewed, carefully lift it out of the engine bay and have some paper towels or rags to hand to catch any old oil. Put the filter housing into a container to collect the oil inside it.

5 OIL FILTER SEAL

There are different designs of oil filter for the A4 engine, so check how the old filter has been fitted and make sure the new one is fitted in the same position. Renew the seal around the thread of the housing and lubricate it with clean engine oil. Refit the housing and new filter, tightening it to 25Nm.

6 RENEW AIR FILTER

The air filter is located in a housing on the offside front of the engine bay. Detach the electrical plug for the air mass meter and undo the clip for the intake hose, followed by six Torx T25 screws. Remove the air filter housing lid, then extract the old filter. Clean inside the housing before fitting a new one.

7 GREASE BONNET RELEASE

Spray light grease over the release mechanism on the front underside of the bonnet and the lock on the top of the slam panel. It’s also worthwhile greasing all hinges for the doors and the locking mechanism for the boot.

8 CHECK BRAKE FLUID

The brake fluid reservoir is located at the back of the engine bay, close to the scuttle panel. Check the fluid inside with a brake fluid tester. If it needs to be renewed, use DOT 4 rated fluid. IVC uses a pressure-operated brake bleeder to renew the brake fluid.

9 POWER STEERING FLUID

Use a large, wide flat-blade screwdriver to undo the plastic cap of the PAS reservoir (a slotted cross in the top of the cap allows it to be undone). Wipe the dipstick on the bottom of the cap with a clean, lintfree cloth, then reinsert it and check the level.