3054 Engine Caterpillar

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Illustration 1	g00314806
Measure The Radial Movement Of The Valve In The Valve Guide. (1) Valve guide (2) Radial movement of the valve in the valve guide (3) Valve stem (4) Dial indicator (5) When the valve head is lifted, the edge of the valve head is the following value: 15.0 mm (0.60 inch)

1. Place a new valve in the valve guide.

2. Place a dial indicator with a magnetic base on the face of the cylinder head.

3. Lift the edge of the valve head to a distance of 15.0 mm (0.60 inch).

4. Move the valve in a radial direction away from the dial indicator. Make sure that the valve moves away from the dial indicator as far as possible. Position the contact point of the dial indicator on the edge of the valve head. Set the position of the needle of the dial indicator to zero.

5. Move the valve in a radial direction toward the dial indicator as far as possible. Note the distance of movement which is indicated on the dial indicator. If the distance is greater than the maximum clearance of the valve in the valve guide, replace the valve guide. The maximum clearance is listed in the Specifications Module, "Cylinder Head Valves".

Replacing Valve Guides and Valve Inserts

Note: The 157-3720 Valve Seat Cutter (31/46 Degree) has two cutting sides. One side is for cutting the valve seat in the valve insert for naturally aspirated engines which have 46 degree valve seats. The other side of the cutter is for cutting the valve seat in the valve insert for turbocharged engines which have 31 degree valve seats.

When new valve guides are installed, new valves and new valve seat inserts must be installed. Valve guides and valve seat inserts are supplied as a partially finished part. The unfinished valve guides and unfinished valve seat inserts are installed in the cylinder head. Then, the valve guides and valve inserts are cut and reamed in one operation with special tooling. This procedure ensures the concentricity of the valve seat to the valve guide in order to create a good seal.

Note: All lubricant must be removed from the outside of the inlet and exhaust valve guides before the valve seal is installed.

Perform the following procedure in order to correctly adjust new valve guides and valve inserts:

1. Remove the original valve guide and the original valve seat insert. Install a new valve guide and a new valve seat insert. Refer to the Disassembly and Assembly manual for removal and installation procedures for valve guides and valve inserts.

   Note: Do not cut the valve seat before the valve guide is installed.

2. Machine the recess in the cylinder head for the valve seat insert. Refer to the dimensions that are listed in the Specifications Module. Use the bore of the new valve guide as a guide.

   Remove all debris. Thoroughly clean the recess for the valve seat insert.

3. Ensure that the valve seat insert does not protrude above the bottom face of the cylinder head. If the valve seat insert protrudes above the bottom face of the cylinder head, the back of the valve seat insert must be machined. Refer to the Specifications Module for dimensions of the valve seat insert.

4. Press the valve seat insert into the recess of the cylinder head for the valve seat insert. Use a hydraulic press or a driver in order to install the valve seat insert. Use the bore of the new valve guide as a guide. Refer to the Disassembly and Assembly Module for additional information regarding tools. Ensure that the bottom of the valve seat insert fully contacts the bottom of the recess in the cylinder head.

5. Cut the valve seat with the valve seat cutter. Refer to the Specifications manual for the correct angles and dimensions for the valve seats and depth of the valve head. Ensure that the depth of the valve head below the face of the cylinder head is within the tolerance.