SENSOR GP-PRESSURE 3881307 - Caterpillar

Introduction
Use the procedure that follows when replacing a head gasket on the above engines. This procedure can help ensure the integrity of the gasket joint between the cylinder head and engine block.
When using pressure air wear a protective face shield and protective clothing. The maximum air pressure at the nozzle must be less than 205 kPa (30 psi) for cleaning purposes.
Cylinder Head Bolt Identification
All 1100, 3100 and earlier 3200 Family Engines use cylinder head bolts with a torque specification of 130 N m (95 lb ft). These earlier bolts can be identified by the six dash marks on the bolt head, as shown at (A) above.Later 3204 and 3208 Engines use stronger cylinder head bolts with a higher torque specification. These bolts can be identified by the seven dash marks on the bolt head, as shown at (B).
The higher cylinder head bolt torque can be used on earlier engines ONLY if the earlier bolts are replaced by the later high strength bolts (seven dash marks on the bolt head). If the earlier bolts are tightened to the later bolt torque specification, the bolts may yield (stretch) and lose their clamping force, or break.
Cylinder Head Installation
1. After removing the cylinder head, scrape any remaining gasket material and carbon residue from the cylinder block top deck and the cylinder head bottom deck. Finish cleaning the deck surfaces with a light abrasive material, such as steel wool.2. Visually inspect the cylinder block top deck and the cylinder head bottom deck surfaces for erosion, grooves and nicks. Give particular attention to the deck surface locations that contact the gasket fire rings.3. Inspect the cylinder block top deck and the cylinder head bottom deck surfaces for flatness. The decks must be flat to within 0.15 mm (.006 in) for the total span, and to within 0.08 mm (.003 in) for any 152 mm (6.0 in) span. Give particular attention to the deck area between the cylinder bores.4. If erosion, grooves, nicks, or out-of-flatness is discovered (steps 2 and 3), the deck must be resurfaced. Remove only the material necessary to bring the deck surface back into specification. The Specifications section of the Service Manual gives the minimum dimension between the centerline of the crankshaft and the cylinder block top deck. It also gives the minimum dimension between the cylinder head bottom deck and rocker arm mounting surface.5. Inspect the threaded head bolt holes in the cylinder block. Be sure the threads are clean and in good condition. If necessary, use the correct size tap to recondition the threads. Use pressurized air to remove foreign material from the threaded holes.6. Make sure the deck and head gasket surfaces are clean and dry. Install a new head gasket. Do not use any type of gasket coating or sealer on the head gasket or deck surfaces.7. Be sure the head bolt threads are in good condition and clean. DO NOT use anti-seize compound or Molykote Paste on the bolts. Put 6V4876 Molykote Lubricant on the head