SPACER 8J4376 - Caterpillar

Illustration 3 g00286269
8T-2700 Blowby/Air Flow Indicator The 8T-2700 Blowby/Air Flow Indicator checks the amount of blowby. See Special Instructions, SEHS8712 for more information on using this tool.Compression
An engine that runs roughly can have a leak at the valves. An engine that runs roughly can also have valves that need an adjustment. Remove the head and inspect the valves and valve seats. This is necessary to find those small defects that do not normally cause a problem. Repairs of these problems are normally done when you are reconditioning the engine.Cylinder Head
The cylinder heads consist of three main components that can be removed:
valve seat inserts
valve guides
bridge dowelsWhen any of these components are worn or when these components are damaged, these components can be removed. Refer to Disassembly and Assembly for the replacement of these components.Bridge Adjustment
When the head is disassembled, keep the bridges with the respective cylinders. Adjustment of the bridge will be necessary for the following reasons.
the valves are ground
reconditioning of the cylinder head is completedThe bridge should be checked and/or adjusted each time the valves are adjusted. Use the procedure that follows to make an adjustment to the bridge.
Illustration 4 g00363479
Bridge adjustmentNote: Valves must be fully closed.
Apply engine oil on the bridge dowel in the cylinder head. Apply engine oil in the bore in the bridge.
Install the bridge with the adjustment screw toward the exhaust manifold.
Loosen the locknut for the adjustment screw. Loosen the adjustment screw for several turns.
Put a force on the bridge with a finger. This will keep the bridge in contact with the valve stem opposite the adjustment screw.
Turn the adjustment screw clockwise until the adjustment screw makes contact with the valve stem. Then, turn the adjustment screw 30 degrees more in a clockwise direction. This will make the bridge straight on the dowel. Also, this will make compensation for the clearance in the threads of the adjustment screw.
Hold the adjustment screw in this position. Tighten the locknut to 28 4 N m (21 3 lb ft).
Apply engine oil at the point that the rocker arm makes contact with the bridge.Valve Lash Setting
Valve lash is measured between the rocker arm and the bridge for the inlet valves. Valve lash is measured between the rocker arm and the valve stem for the exhaust valve. All of the clearance measurements and the adjustments must be made with the engine stopped. The valves must be FULLY CLOSED. Valve Lash Check: Engine Stopped
Table 3
Check for Valve Lash: Engine Stopped