Jeep 68280511AB Head-Engine Cylinder

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Several tools are needed to accomplish this procedure thus; one is expected to go through the whole procedure to get all the tools needed before starting the work. First, remove the fuel system pressure and then, set the negative end of the battery cable. Taking off the engine's upper and lower intake manifolds should be done when the cooling system is drained; likewise, the ignition coils and spark plugs can be removed if needed. Remove the exhaust manifold bolted to the cylinder head being replaced, the valve cover, rocker arms and shafts. Take off the timing belt guards, make positive that both TDC marks are aligned, and then lose the timing belt, but if the same belt will be re attached then the direction of its rotation should be noted. To remove the camshaft sprocket hex, hold the hex using a wrench while applying a socket and a breaker bar to the flange to remove the camshaft bolt which is very tight, use new camshaft sprocket bolts as the left and the right camshaft sprocket bolts are equivalent. Pull the camshaft thrust plate out on the rear side of the head and move the camshaft backward approximately 3-9/32-inches in order to provide clearance for the withdrawal of the sprocket and bolt. Loosen but do not remove the bolts that holds the rear timing belt cover to the cylinder head only. Take a new head gasket and lay it on a piece of cardboard to draw the cylinders and the bolt pattern on it, mark the front side of the engine and then mark the head gasket with small holes in the bolt hole locations in order to store each cylinder head bolt in the correct location after they have been removed. Turn the cylinder head mounting bolts 1/4 turn at a time untill each can be turned with bare hands following a sequence that is the reverse of the tightening sequence and keep the bolts in the cardboard holder. Carefully raise the head(s) off the engine making sure not to pry between the head and block and if necessary to break gasket joint, one has to use hammer and block of wood. Following removal, the head should be set on wooden block to avoid any damages on the gasket surfaces. If, for any reason the camshaft needs to be inspected or removed, this can only be done with the cylinder head removed from the engine. During assembly, be very careful to see that the surfaces of each cylinder head and block are indeed clean by scraping off carbon and old gasket material after which, you should wash them with lacquer thinner or acetone. By simply examining the block and head mating surfaces, the professional has to identify any possible damages, and if yes, use a tap to chase the threads in the head bolt holes. After that, place the new gasket over the dowel pins indicated on the block, make sure that it is installed correctly, and gently put the head in the block on the gasket. Loosen and then re-tighten the bolts in the sequence and to the torque specified, fit the rear timing belt cover to cylinder head bolts, slide the camshaft back into the cylinder bear, fit the camshaft sprocket and bolt new. Finally, fit the camshaft thrust plate at the back of head with a new O-ring, tighten the bolts with said torque and than following the procedure above in reverse to remove the camshaft thrust plate. Replace the oil and the oil filter, check and fill the cooling system, operate the engine and check for any sign of leakage.

Carefully place the heads on the block without disturbing the gaskets, coat the head bolt threads with engine oil, and install them in their original locations.

Raise the front of the vehicle securely on jackstands and drain the engine oil and coolant.

Using a breaker bar and the appropriate sized socket, loosen the cylinder head bolts in 1/4-turn increments until they can be removed by hand, following the reverse order of the lightening sequence to avoid warping or cracking the head.