Contents: Disassembly ⇓ Assembly ⇓
Disassembly
Loosen the camshaft toothed pulley mounting bolt, holding the shaft from turning with a wrench.
Remove the camshaft timing pulley.
Remove the rocker arm oil lines.
Remove the camshaft thrust washer.
Remove the camshaft.
Release the valves from the crackers by compressing the valve springs with a valve spring compressor.
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Remove the springs with plates and valve springs, put them in order.
Remove the valves.
Remove the valve guide oil seals and spring washers.
Press out the camshaft oil seal.
Wash and clean the removed parts and the cylinder head.
Check the valve seat chamfers for pitting, corrosion, or damage. Minor damage can be removed by grinding, removing as little metal as possible. After grinding, thoroughly rinse the seats and cylinder head channels and blow them out with compressed air. Remove carbon deposits from the valves. Make sure there is no deformation of the valve stem or cracks in the plate. Check the condition of the valve seat chamfer. In case of minor damage, it can be ground, maintaining the required chamfer angle. Check the clearance between the valve guides and the valve stems.
If the clearance between the guide sleeve and the valve is increased, press out the valve guide sleeve using the Mazda 49 0249 010A punch towards the upper plane of the cylinder head.
Press in a new guide bushing with the retaining ring fitted using the same Mazda 49 0249 010A punch until it rests against the cylinder head body.
Check the mating surface of the cylinder head for warpage.
Assembly
Press the valve stem seals onto the valve guides.
Insert the valves into the guide bushings.
Install the thrust washers, springs, and spring plates. Compress the springs with a special device and install the valve crackers.
Lubricate the camshaft with engine oil and install it in place.
Install the camshaft thrust washer.
Press a new seal onto the front end of the camshaft, after lubricating it with engine oil.
Install the rocker arm lubrication lines.
Insert the key into the camshaft socket and place the toothed pulley on the shaft.
After locking the camshaft with a wrench, tighten the toothed pulley mounting bolt.
Turn the camshaft pulley until the timing marks on the valve timing mechanism are aligned.