Chapter 1 Routine maintenance and servicing

HCS engine in-car repair procedures 2A•56.8 Flat on the rocker shaft (arrowed) tosame side as rocker arm adjusting screws8 Reassemble in the reverse order ofdismantling. Make sure that the “flat” on therear end of the rocker shaft is to the same sideas the rocker arm adjusting screws (closest tothe thermostat end of the cylinder head whenfitted) (see illustration). This is essential forthe correct lubrication of the cylinder headcomponents.9 Refit the rocker shaft assembly. As it isfitted, ensure that the rocker adjuster screwsengage with their corresponding pushrods.10 Refit the rocker shaft retaining bolts,hand-tighten them and then tighten them tothe specified torque wrench setting. As theyare tightened, some of the rocker arms willapply pressure to the ends of the valve stems,and some of the rocker pedestals will notinitially be in contact with the cylinder head -these should pull down as the bolts aretightened to their specified torque. If for anyreason they do not, avoid the temptation toovertighten in order to pull them into position;loosen off the bolts, and check the cause ofthe problem. It may be that the rocker adjusterscrews require loosening off in order to allowthe assembly to be tightened down asrequired.11 Adjust the valve clearances as describedin Section 5.7 Cylinder head -removal and refitting 3RemovalNote: The following procedure describesremoval and refitting of the cylinder headcomplete with inlet and exhaust manifolds. Ifwished, the manifolds may be removed first,as described in the relevant Part of Chapter 4,and the cylinder head then removed on itsown.1 On fuel injection engines, depressurise thefuel system as described in Chapter 4, Part B.2 Disconnect the battery negative (earth) lead(refer to Chapter 5A, Section 1).3 Refer to Chapter 4A or 4B as applicableand remove the air cleaner.4 Refer to Section 4 and remove the rockercover.5 Refer to Chapter 1 and drain the coolingsystem.6 Disconnect the hoses from the thermostathousing.7 Disconnect the heater (coolant) hoses fromthe inlet manifold and CFi unit, whereapplicable.Whenever you disconnectany vacuum lines, coolant oremissions hoses, wiringconnectors and fuel lines,always label them clearly, so that theycan be correctly reassembled. Maskingtape and/or a touch-up paint applicatorwork well for marking items. Takeinstant photos, or sketch the locationsof components and brackets.8 Disconnect the accelerator and chokecables as applicable (see Chapter 4A or 4B).9 Disconnect the vacuum and breather hosesfrom the carburettor/CFi unit, and inletmanifold as applicable.10 Disconnect the fuel feed and return linesat the carburettor, or at the quick-releasecouplings, then unclip the fuel hoses from theinlet manifold; use rag to soak up any spiltfuel.11 Disconnect the HT leads from the sparkplugs and the support bracket. Unscrew andremove the spark plugs.12 Disconnect the electrical leads from thetemperature gauge sender, radiator coolingfan, the engine coolant temperature sender,and the anti-run-on (anti-dieselling) valve atthe carburettor.13 Disconnect the remaining wiring multiplugsfrom the engine sensors at the inletmanifold and from the oxygen sensor (wherefitted) in the exhaust manifold or downpipe.14 On vehicles equipped with a pulse-airsystem, remove the pulse-air piping and filterassembly as described in Chapter 4E.15 Chock the rear wheels then jack up thefront of the car and support it on axle stands(see “Jacking and Vehicle Support”).16 Undo the retaining nuts and bolts, anddisconnect the exhaust downpipe from themanifold. Remove the flange gasket. (Notethat both the gasket and the joint self-lockingnuts must be renewed.) To prevent theexhaust system from being strained, tie thedownpipe up using strong wire or a length ofcord to support it. Lower the vehicle.17 Undo the four retaining bolts and lift clearthe rocker gear assembly from the cylinderhead.18 Lift out the pushrods. Keep them in orderof fitting by labelling them 1 to 8, starting fromthe thermostat end of the cylinder head.Alternatively, push them through a piece ofcard in their fitted sequence.19 Progressively unscrew and loosen off thecylinder head retaining bolts in the reversesequence to that shown for tightening (seeillustration 7.27a). When they are allloosened off, remove the bolts, then lift thecylinder head clear and remove the gasket. Ifit is stuck, tap it upwards using a hammer andblock of wood. Do not try to turn it, as it islocated by dowels; make no attemptwhatsoever to prise it free using a screwdriverinserted between the block and head faces.The gasket must always be renewed; it shouldbe noted that the cylinder head retaining boltsmay be re-used, but only once. They shouldbe marked accordingly with a punch or paintmark. If there is any doubt as to how manytimes the bolts have been used, they must berenewed.20 To dismantle/overhaul the cylinder head,refer to Part D of this Chapter. It is normal forthe cylinder head to be decarbonised and thevalves to be reground whenever the head isremoved.Preparation for refitting21 The mating faces of the cylinder head andcylinder block must be perfectly clean beforerefitting the head. Use a hard plastic or woodscraper to remove all traces of gasket andcarbon; also clean the piston crowns. Takeparticular care during the cleaning operations,as aluminium alloy is easily damaged. Also,make sure that the carbon is not allowed toenter the oil and water passages - this isparticularly important for the lubricationsystem, as carbon could block the oil supplyto the engine’s components. Using adhesivetape and paper, seal the water, oil and boltholes in the cylinder block.To prevent carbon enteringthe gap between the pistonsand bores, smear a littlegrease in the gap. Aftercleaning each piston, use a small brushto remove all traces of grease andcarbon from the gap, then wipe awaythe remainder with a clean rag.22 Check the mating surfaces of the cylinderblock and the cylinder head for nicks, deepscratches and other damage. If slight, theymay be removed carefully with a file, but ifexcessive, machining may be the onlyalternative to renewal.23 If warpage of the cylinder head gasketsurface is suspected, use a straight-edge tocheck it for distortion. Refer to Part D of thisChapter if necessary.24 Clean the threads of the cylinder headbolts or fit new ones (as applicable) and cleanout the bolt holes in the block. Screwing a boltinto an oil-filled hole can (in extreme cases)cause the block to fracture, due to thehydraulic pressure.Refitting25 Check that the new cylinder head gasketis the same type as the original, and that the“TOP” (or “OBEN”) marking is facingupwards. Locate the new cylinder head2A1595Ford Fiesta Remake