How to Replace a Blown Head Gasket in a Toyota Truckby Charles W. St.Clair
When a Toyota truck overheats, multiple costly problems may result. One common consequence is the cracking or failure of the cylinder head gasket. On Toyotas, these gaskets do not typically fail alone, but rather as the result of the failure of some other engine system, typically the cooling system. Replacing this gasket is a costly and time-consuming repair. Many complicated parts and procedures must be dealt with in order to ensure that the engine is reassembled properly.
Purchase or download a copy of the factory service manual for your year and model of Toyota truck. This book contains essential information on specifications, illustrations of removal sequences and invaluable advice on inspection procedures. If your truck or 4runner was built between 1979 and 1994, the manual is the same.
Remove any components that may prevent easy removal of the cylinder head. This may include the air intake manifold, exhaust manifold, timing chain, fuel hoses, distributor cap and spark plug wires.
Expose the cylinder head bolts by removing the cylinder head cover. The cylinder head bolts must be removed in a specific sequence according to the service manual. Failure to do so may result in permanent, irreversible damage to the cylinder head.
Check the cylinder head for trueness and flatness using a ruler or straightedge. Inspect the cylinder bores for damage. Inspect the cylinder head for scratches, nicks or other damage. Remove any debris and old gasket material using a solvent such as acetone. If only minor damage to the head surfaces is detected, remove it with a file. If excessive damage is present, machining will be necessary.
Clean the cylinder head bolt holes with a correctly sized tap. Chase the holes with compressed air to remove crud. Align the gasket. Sealants are typically not necessary, but if they are required the manual with specify what type of sealant.
Replace the cylinder head and reinstall the head bolts. Use the sequence and tightening instructions provided in the manual. Use the correct torque as specified in the manual. Failure to do so will result in costly damage.
Reinstall all engine components in the reverse order from disassembly. Run the engine and check for leaks.
- When replacing a head gasket, be sure to check the integrity of all parts and components that become exposed during this repair sequence. This may be the perfect time to replace the timing chain or check the valve clearances.
- Be sure to safely handle all engine fluids. Engine fluids are toxic and potentially dangerous. Be sure to follow local rules regarding storage and disposal.
Items you will need
- Factory service manual
- Full set of wrenches, sockets, pliers, drivers, and probes
- Compressed air and impact wrences
- Torque wrench
- Protective gear for eyes, hands, ears and lungs
- Covered area such as garage or tent
- Fluid drain pans and storage containers
- old engine image by John Sfondilias from Fotolia.com