UNDERBONNET CHECKS & FILTERS
1 COOLANT & PRESSURE CAP
The plastic coolant expansion tank is located at the front of the engine bay. Release the cap when the engine is cold. Test the freezing capacity of the coolant and top up with OAT antifreeze. Check the pressure cap and renew it if it’s old or damaged. If it cannot maintain pressure, coolant will be lost.
2 CHECK COOLANT PIPES
Inspect the condition of the coolant pipes, especially a plastic T-piece connector behind the radiator. On the ZT turbo, there’s a small outlet to feed coolant to the turbo, which can fracture and leak. A new one costs about £25.
3 PAS FLUID
The power steering fluid reservoir sits on the offside rear of the engine bay. Release the plastic cap, which has a dipstick underneath. Wipe the dipstick, refit the cap, then remove and check the level. Top up with Dexron II power steering fluid.
4 INSPECT DRIVEBELTS
There are two auxiliary drivebelts, both of which have automatic tensioners. One of the belts is for the alternator and air-conditioning (if fitted), while the other is for the PAS pump. They should be renewed every 50,000 miles, at the same time as the timing belt.
5 TEST BRAKE FLUID
Unclip the plastic offside scuttle panel grille to access the brake fluid reservoir. The level can be visually checked by looking at ‘MIN’ and ‘MAX’ markers on the side of the reservoir. Top up with DOT 4 fluid. Its condition can be checked using an electronic brake fluid tester.
6 BATTERY, FUSES & RELAYS
Ensure the battery terminals are clean and secure. Test the 12V battery with a multimeter or dedicated device to confirm its condition. Check that all electrical equipment is operational. If any problems are found, look for the respective fuses using the diagram on the underside of the fusebox cover.
7 RENEW AIR FILTER
The filter is located inside a plastic housing on the nearside of the engine bay. Undo two crosshead screws to release the lid of the housing, lift it a little and extract the old filter. Clean inside the housing before replacing the filter. We fitted a reusable K&N filter, which should be cleaned every 50,000 miles.
8 FIND THE POLLEN FILTER
The pollen filter is on the bulkhead nearside and is quite awkward to renew. Unclip the plastic scuttle panel grille, then release three of the trim plugs holding the main scuttle panel. Lift it a little to extract the cover underneath. You can now see the pollen filter, but won’t be able to remove it.
9 REMOVE ECU
Before the pollen filter can be removed, it’s worthwhile extracting the ECU to create more space. Detach the ECU’S plug connector, then unclip it from its cage and lift it out. Take out the old pollen filter, but don’t fit the new one until you inspect and clean the drainage hole.
10 CLEAN DRAINAGE
Use a long, thin steel rod to clean the drain hole below the pollen filter. This runs through to a drain tube close to the exhaust (there are two, the other being for the air-conditioning). If it’s blocked, the bulkhead area can fill with water, drowning the ECU and heater. Fit a new pollen filter and refit the trim panels.
11 REMOVE COVER & COIL PACKS
Undo the three 8mm bolts that secure the spark plug cover to the rocker cover. There are two coil packs, each held by a couple of 8mm bolts, which need to be undone to access two of the spark plugs. The other two plugs are hidden by their HT leads. Carefully release all of these parts to access the plugs.
12 RENEW SPARK PLUGS
Use a 16mm or 5/8 in spark plug socket with an extension and ratchet to renew all four plugs. When fitting the new ones, make sure the rubber insert in the spark plug socket stays inside the socket. If it falls off, try using a length of rubber hose to fit the spark plug initially, then tighten it without the rubber insert. Tighten to 25Nm.
13 REMOVE UNDERTRAY
The undertray needs to be detached to drain the engine oil. It’s secured with several Dzus or quick-release fasteners which may be corroded, missing or replaced for something else. Undo and remove the 15mm sump plug and drain the old oil into a container. It may take several minutes for the oil to drain.
14 RENEW OIL FILTER
While the engine oil is draining, use an oil filter wrench or water pump pliers to undo the spin-on oil filter – it’s located close to the drain plug. Add a smear of fresh engine oil to the seal of the new filter, then fit and tighten it by hand. Refit the drain plug with a new washer and tighten it to 25Nm.
15 10W-40 SEMI-SYNTHETIC
According to Millers, the ZT’S K-series engine requires up to five litres (service-fill/dry-fill) of semi-synthetic 10W-40 oil. Pour this in via the filler cap, run the engine to ensure the oil pressure light goes out, switch off and check the level on the dipstick (wipe and re-dip it). Top up if necessary.
16 GEARBOX OIL
There’s an inspection hole on the nearside of the Getrag five-speed gearbox on the ZT turbo, which can be undone with an 8mm Allen key bit. Millers recommends topping up with Trident 10W-40 semi-synthetic or 75W-80 fully-synthetic.
17 OPAQUE HEADLIGHTS
The exterior surface of the headlights can turn opaque due to UV light damage. However, they can often be revived with a headlight restoration kit. When inspecting the headlights, check their operation to ensure the bulbs are in good working order.
18 BULB REPLACEMENT
Headlight and front indicator bulbs can be renewed via the engine bay, although space is tight. Rear bulbs are accessed via the boot, where the trim will need to be detached and moved aside. Unclip the circuit board from inside, which includes the bulbs.
19 DOOR LOCKS
Operate the central locking and check that all the doors can be locked and unlocked from inside and out. Door latch failure is a common problem, resulting in a door not being able to lock or unlock via the central locking. The easiest solution is to fit a new or secondhand lock mechanism. A new lock is around £70.
20 BOOT LEAKS
If water is leaking into the boot, check the trim on the rear quarter panel is fully clipped in position, otherwise water can get through the mounting holes. Also, inspect the rear light seals and the seal around the rear screen; if the rubber has perished, water can leak into the boot.
21 FRONT COIL SPRINGS
Visually inspect the coil springs on the front suspension (part of the Macpherson struts). Stones can get trapped underneath the base of the springs and wear them away. Do not touch the coil springs, but inspect them for corrosion and fractures, particularly at the ends where they’re susceptible to breaking.
22 REAR COIL SPRINGS
The rear springs are separate to the dampers and can be inspected from underneath or by removing the road wheels. Each spring sits on a spring pan, which forms the upper suspension arm and can corrode and dislodge the spring. Check the condition of the arm using a screwdriver. Also, look over the dampers for leaks as they are a common issue.
23 ARBS & DROPLINKS
Anti-roll bars (ARBS) are fitted to the front and rear of the ZT. Wiggle the droplinks to test for play in the balljoints – the fronts wear more often than the rears. Lever a pry bar or similar against the ARB to check the rubber D-bushes for the mounts are not worn. This is easier to do on the rear ARB, because there’s more room.
24 REAR LOWER ARMS
Use a pry bar or tyre lever to test the bushes on the ends of the rear lower suspension arms. With the rear of the vehicle raised and secured, move the rear road wheels up and down and in and out to look for play in the outer bush.
25 FRONT LOWER BALLJOINTS
Check for excessive play in the outer balljoint for the front lower suspension arms by levering against them with a pry bar or tyre lever. Inspect the condition of the CV and driveshaft boots, looking for cracks and water/dirt ingress.
26 WHEEL WIGGLE
With the corner of the vehicle raised and safely secured, wiggle each road wheel from top to bottom and side to side to check for play in the suspension bushes, track rod ends (front only) and wheel bearings. Any play detected may be identified during our other suspension checks.
27 FRONT ARM BUSHES
The rearmost bush on the front lower suspension arms can become worn, resulting in suspension movement under braking and visible movement when conducting the wheel wiggle test in Step 26. New bushes are available for around £40 and need to be pressed off and onto the lower arm.
28 INSPECT THE SILLS
The sills on the ZT are known to corrode and fail the MOT, so check all the way along the underside with a small hammer or blunt screwdriver. The back section of the sills is more prone to corrosion, especially close to the jacking points, which may have crumbled or folded if they have been used to raise the vehicle.
29 EXHAUST & BRAKE PIPES
Closely inspect the exhaust system, especially the joins, hangers and mounts. If it’s safe, run the engine and listen for leaks. Check the front-to-rear brake pipes, which are routed under the offside floors and can rust. Renew the brake pipes if the corrosion has weakened their walls and cannot be cleaned off.
30 TANK STRAPS
The petrol tank is a saddle-style design, located underneath the rear of the vehicle, below the rear seats. It’s secured with an H-shaped tank strap, which is known to corrode and break, leaving the tank balanced across the exhaust system and in danger of damaging the wiring for the tank’s sender unit. Check the condition of the tank strap and protect the exterior if surface corrosion is visible.
31 REMOVE CALIPERS
Single-piston calipers with 7mm Allen key slider bolts are fitted all round on the ZT. To service each brake, remove the spring clip on the outside, then undo the two 7mm Allen key bolts (extract their dust covers first). Prise off the caliper, leaving the outer brake pad attached to the caliper carrier and the inner pad secured to the caliper.
32 CLEAN & REASSEMBLE
Check there’s more than 3mm of braking material on the pads. Spray the caliper and carrier with a little brake cleaner, then use a wire brush to remove dirt and brake dust. Clean the slider bolts using abrasive paper. Apply a smear of brake grease to the slider bolts and the top and bottom edges of the brake pads before reassembling them. Tighten the slider bolts to 28Nm.