Chapter 1 Routine maintenance and servicing

Engine removal and overhaul procedures 2D•158.15 Grinding-in a valve seatbench, with a block of wood at each end togive clearance for the valve stems.15 Smear a trace of (the appropriate gradeof) valve-grinding compound on the seat face,and press a suction grinding tool onto thevalve head. With a semi-rotary action, grindthe valve head to its seat, lifting the valveoccasionally to redistribute the grindingcompound (see illustration). A light springplaced under the valve head will greatly easethis operation.16 If coarse grinding compound is beingused, work only until a dull, matt even surfaceis produced on both the valve seat and thevalve, then wipe off the used compound, andrepeat the process with fine compound. Whena smooth unbroken ring of light grey mattfinish is produced on both the valve and seat,the grinding operation is complete. Do notgrind in the valves any further than absolutelynecessary, or the seat will be prematurelysunk into the cylinder head.17 When all the valves have been ground-in,carefully wash off all traces of grindingcompound, using paraffin or a suitablesolvent, before reassembly of the cylinderhead.Valve components18 Examine the valve springs for signs ofdamage and discolouration, and also measuretheir free length (see illustration). If possible,compare each of the existing springs with anew component.19 Stand each spring on a flat surface, andcheck it for squareness. If any of the springs8.18 Checking the valve spring free lengthare damaged, distorted, or have lost theirtension, obtain a complete set of new springs.20 Check the spring upper seats and colletsfor obvious wear and cracks. Anyquestionable parts should be renewed, asextensive damage will occur if they fail duringengine operation. Any damaged orexcessively-worn parts must be renewed; thevalve spring lower seat/stem oil seals must berenewed as a matter of course whenever theyare disturbed.21 Check the rocker gear components andhydraulic tappets as described in earlier partsof this Chapter according to engine type.9 Cylinder head - reassembly41 Before reassembling the cylinder head, firstensure that it is perfectly clean, and that notraces of grinding paste are left in the head oron the valves and guides. Use compressedair, if available, to blow out all the oil holes andpassages.2 Commence reassembly of the cylinderhead by lubricating the valve stems andguides with clean engine oil.HCS engines3 Insert the first valve into its guide. Wipe theoil from the top of the valve stem, then windsome insulation tape over the split colletlocation groove, to protect the new valve stemseal as it is fitted over the valve and intoposition. As the seal is fitted, support thevalve to prevent it from falling out; push theseal down the valve, and locate it flush to thevalve guide. Press the seal down firmly andevenly using a suitable diameter tube orsocket, and take care not to distort the seal asit is located. Check that the seal spring iscorrectly located to ensure that it sealscorrectly, then remove the tape from the valvestem (see illustrations).4 Locate the valve spring and its retainer overthe valve stem, and engage the valve springcompressor. Compress the spring andretainer just enough to allow the split colletsto be inserted in the location groove in thevalve stem. Holding the collets in position,slowly release and remove the valve springcompressor.A little grease applied to the colletgroove will help retain them in position.5 Repeat the operation on the remainingvalves, ensuring that each valve is fitted in itsappropriate location.6 On completion, support the cylinder headon a suitable piece of wood, and lightly strikethe end of each valve stem in turn with aplastic- or copper-faced hammer tofractionally open the valve and seat the valvecomponents.CVH and PTE engines7 Working on one valve at a time, fit the lowerretainer into position (see illustration).8 Check for correct orientation, then fit thenew oil seal into position over the guide. Drive2D9.3a Tape the end of the valve stem beforefitting the valve stem seal9.3b Press the seal into position using asuitable socket9.7 Fit the lower retainer1595Ford Fiesta Remake