Service
Subplate and Rocker Assemblies
NOTE: Air Valve Repair Kit 222959 is available. Parts included in the kit are marked with a symbol ({). For the best results, use all the parts in the kit.
Disassembly
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the Pressure Relief Procedure on page 10.
1.Stop the pump at the middle of its stroke. Relieve the pressure before performing any service.
2.Follow the steps under Air Motor Shroud Disas- sembly on page 11.
3.Use an allen wrench to remove the six socket screws (28) holding the air valve (25) to the sub- plate (23). See Fig. 3 on page 12. Remove the air valve.
NOTE: To replace or service the air valve, refer to pages
4.Remove the gasket (26) and the two seals (27). Inspect these parts for wear or damage.
5.Remove the two screws (13) and washers (51) holding the bottom cover (61) to the bottom rocker arm cover (62). See Fig. 9.
6.Remove the pad (63, see Fig. 3 on page 12) from the top rocker assembly. Hold the stud (30) with a wrench while unscrewing the nut (33). Pull the stud
(30)out and disassemble the rocker assembly. Push the sleeve (31) out of the rocker arm (29). Inspect the rocker arm, sleeve, and bearings (32) for wear.
7.Disassemble the bottom rocker assembly as explained in step 6.
8.Using a 17 mm box wrench, remove the capscrew
(43)and gasket (47) holding the exhaust manifold
(45)to the subplate (23). Remove the two liners
(44)from the cavities in the manifold. Check that the vertical slot (V) in the manifold is clear of dirt or blockage; clean with a brush or compressed air. See Fig. 9.
9.Using an allen wrench, unscrew the eight socket screws (41) holding the subplate (23) to the cylin- der (1). Remove the subplate and the gasket (24). Inspect these parts for wear or damage.
10.Remove the two screws (42), the top rod fitting (20), and the push rod (19) from the motor cap (2). Using an
Reassembly
1.Lubricate the seal (21{) and insert it in the motor cap (2) with the lips facing into the cap. Install the rod fitting (20{). Grease the end of the push rod (19) and insert it in the fitting. Apply thread sealant and torque the screws (42) to
2.Place the gasket (24) on the back side of the subplate (23), aligning the holes in both parts. With the air inlet port (P) facing up, install the subplate on the cylinder (1) with the eight socket screws
(41).Torque to
3.Install the two liners (44) in the cavities of the exhaust manifold (45). Attach the manifold to the subplate with the gasket (47) and capscrew (43), using a 17 mm box wrench. Torque to
4.Lubricate the sleeve (31) and two bearings (32) and install them in the rocker arm (29). Position the rocker arm between the top flanges of the subplate (23).
5.Note that the rocker arm cover (62) has two tabs that are
6.Assemble the bottom rocker assembly as ex- plained in steps 4 and 5. Install the bottom cover
(61)and secure to the rocker arm cover with the two screws (13) and washers (51).
7.Install the two seals (27{) and the gasket (26{). See the Detail in Fig. 3 on page 12.
8.Install the air valve (25), using a 6 mm allen wrench and six socket screws (28). Torque to
9.Follow the steps under Air Motor Shroud Reas- sembly on page 11.
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