4TNV98 & 4TNE98 Diesel Engine Section 3. Engine82Disassembly of 4-Valve Cylinder HeadPrepare a clean, flat working surface on aworkbench large enough to accommodate thecylinder head assembly. Discard all gaskets, O-ringsand seals. Use new gaskets, O-rings and seals onreassembly of the cylinder head.1. Drain the coolant from the engine into a suitablecontainer. See Drain, Flush and Refill CoolingSystem with New Coolant on page 163.CAUTIONIdentify all parts and their location using anappropriate method. It is important that all partsare returned to the same position during thereassembly process.2. Remove the high pressure fuel injection lines(Figure 6-37, (1)). See Removal of Fuel Injectorson page7-31.Figure 6-37CAUTIONRemove or install the high-pressure fuelinjection lines as an assembly wheneverpossible. Disassembling the high-pressure fuelinjection lines from the retainers or bending anyof the fuel lines will make it difficult to reinstallthe fuel lines.3. Disconnect the fuel return hose (Figure 6-37, (2))from the cylinder head.4. Disconnect the hoses (Figure 6-37, (3)) from thecold start device on the fuel injection pump.5. Remove the turbocharger-to-intake manifold hose(Figure 6-38, (1)) (if equipped).6. Disconnect the electrical wire from the intake airheater (Figure 6-38, (12)).7. Remove the intake manifold bolts (Figure 6-38,(11)). Remove the intake manifold (Figure 6-38,(10)). Discard the intake manifold gasket (Figure6-38, (9)).8. Remove the exhaust manifold bolts (Figure 6-38,(7)). Remove the exhaust manifold (Figure 6-38,(6)) with the turbocharger attached. Discard theexhaust manifold gasket. (Figure 6-38, (5)).
