Subaru Head Gasket & Clutch Replacement Continued

Repair Notes Continued :

	Remove the timing belt and cams sprockets. When you remove the timing belt, the passenger side is under no tension, so it won't rotate. On the driver's side, the #2 intake and #4 exhaust valves are open. If you have lined up your timing marks correctly, you will be at the top of the cam lobe, and the cam won't rotate when you remove the timing belt. To get the cams to a safe place, rotate the top (intake) cam counterclockwise, and the bottom (exhaust) cam clockwise. This will "park" the cams to where none are open. Be extreamly careful and double check the documentation - if done improperly the valves could collide and bend.
	Following the procedure outlined in the service manual, remove the cams. Be sure to note the proper orientation of the camshaft caps - each must be installed in its original loaction. Remove the valve lifters and shims one by one, and place each in a labeled sandwich bag - each must go back in its original location. When removing the exhaust cams, the lifters will slide out once the camshaft is removed - have an assistant hold them in until you can bag them. One by one, micrometer the old shims and calculate the new shim required. In my case, I was able to switch some of them and then replace the rest to get the desired clearances. The cam bolts are now visible - you must remove the cams to gain access to the head bolts.
	Now it comes time to remove the heads. When I started, I didn't have a 12-point 14mm 1/2" drive socket. So I was using a 3/8" socket with an extension and breaker bar. The driver's side head bolts were unbelieveably tight, so I used a piece of pipe over the breaker bar. When I put weight on it, the extension broke apart (in my hand!), so I decided that was the time to quit for the night and buy the right 1/2" drive socket. When removing the bolts, follow the loosening procedure, slowly loosening the bolts in the proper sequence, to prevent warping the heads.
	The driver's side head and block. Normal appearance - looks as though a good seal was formed with the head gasket.
	Passenger's side head and block - leak found! The leak was on both the #1 and #3 cylinders, between the cylinder and the coolant passages - no oil was involved. I believe that the leak was caught early, before the leak got big. It seems as though it was only leaking pressure to the cooling system, not leaking coolant into the cylinder - the latter usually cleans the carbon away.
	A view of the blown head gasket itself.
	Some views showing the carbon buildup aroung the top of the cylinder bore and the honing of the cylinder walls. I removed the carbon with some acetone and paper towels, then wiped down the bore with some motor oil on a paper towel.

 

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