Toyota 90913-02090 Intake Valve Seal

Broken valve springs and defective valve stem seals can be replaced without removing the cylinder head, typically requiring two special tools and a compressed air source. If compressed air isn't available, a length of nylon rope can be used to prevent the valves from falling into the cylinder. Begin by removing the camshaft and camshaft housing, then the spark plug from the affected cylinder, or all spark plugs if replacing all valve stem seals. Turn the crankshaft until the piston in the affected cylinder is at Top Dead Center on the compression stroke, working on one cylinder at a time following the firing order. Thread an adapter into the spark plug hole and connect an air hose from a compressed air source. Apply compressed air to the cylinder, ensuring the piston does not move unexpectedly. The air pressure will hold the valves in place. If using nylon rope, position the piston just before TDC, fill the combustion chamber with rope, and leave the end hanging out for easy removal. Rotate the crankshaft until slight resistance is felt, then stuff shop rags into the cylinder head holes to prevent parts from falling in. Use a valve spring compressor to compress the spring, remove the keepers, and then take out the spring retainer, valve spring, and stem oil seal. If air pressure fails to hold the valve closed, the cylinder head may need to be removed for further repairs. Wrap a rubber band or tape around the valve stem to prevent it from falling, then release the air pressure. Inspect the valve stem for damage and ensure it moves freely in the guide. Reapply air pressure to retain the valve in the closed position, lubricate the valve stem with engine oil, and install a new oil seal. Position the spring over the valve, ensuring the closely wound coils are next to the head, then install the valve spring retainer and carefully position the keepers. Remove pressure from the spring tool and ensure the keepers are seated. Disconnect the air hose, remove the adapter, and reinstall the camshaft and housing. Finally, install the spark plug(s), reconnect the wire(s), start the engine, and check for oil leaks and unusual sounds from the valve cover area.