This month’s Belt Focus looks at the installation process behind a Dayco timing belt kit (KTBWP2853) in a 1.4L Fiat 500.
The 1.4-litre MPi petrol engine used in the popular Fiat 500, features a timing belt driven water pump. As replacing the belt also requires the auxiliary drive system to be removed, Dayco recommends that all the systems’ components – primary drive and auxiliary drive – be replaced at the same time.
This step-by-step technical guide aims to help technicians through the process, to avoid complications and ensure a first-rate job. As with all primary drive system jobs, the work should be undertaken when the engine is cold; ideally the vehicle will not have been run for at least four hours.
After disconnecting the battery earth cable, draining the coolant and detaching the reinforcement brace, remove the cowling/side protection from the driver’s side front wheel arch to expose the auxiliary belt system. Slacken the auxiliary belt tensioner with a spanner and take off the belt, then remove the crankshaft pulley.
Disconnect the coolant hoses to the reservoir and remove it. After suitably supporting the engine from underneath, remove the upper engine mount and bracket to reveal the cover of the timing drive system, which can then be removed, starting with the upper half. After checking the timing marks, loosen the tensioner bolt and then remove the tensioner and belt, followed by the water pump.
Fit the camshaft locking tool (186085000) then turn the crankshaft clockwise and align the crankshaft timing marks and install the crankshaft timing tool (2000004500) ensuring that the pin in the pulley is located correctly (Fig.1).
Ensuring that the cooling system has been flushed through and no debris is present, install the new water pump from Dayco kit KTBWP2853, complete with its seal.
Hold the camshaft pulley with the special tool (2000015800) and loosen, but not remove, its bolt, so the pulley can rotate on the shaft, then remove the tool. Replace the tensioner and the belt with the new ones from the kit and using the tool (1860987000), rotate the tensioner anti-clockwise to the end of its stroke (Fig.2) and tighten the nut to between 22-27Nm. Making sure the camshaft pulley doesn’t move by holding it with the special tool (2000015800), tighten the bolt to 132Nm.
Remove the camshaft and crankshaft timing tools and, using the crankshaft pinion, rotate the engine several times and reinstall the tools. Then, while holding the tensioner with the tool, loosen the fastener and rotate the tensioner until its index is centred in the reference window (Fig.3), then retighten the fastening to between 22-27Nm.
Remove the timing tools and refit all the components in their reverse order, but check, and if necessary, replace the crankshaft pulley with Dayco DPV1021 (the fasteners for which should be tightened to 28Nm) and the auxiliary belt tensioner with Dayco APV3711. However, Dayco recommends the auxiliary belt 5PK1145 is always replaced.
For vehicles without air conditioning, Dayco offers the crankshaft pulley DPV1028 and auxiliary belt 4PK668.
Finally, refill the cooling system, start the engine and carefully check for leaks and ensure the radiator fan operates at the correct temperature. Replace the thermostat Dayco DT1078F if necessary. Then, once the engine is cold, check the level of the fluid again.