Piston Oil Seals and Pistons

Portable Pressure Washer Familiarization and Troubleshooting Guide Section 7 • Large Frame Pump

NOTE: When installing the engine adapter having the o-ring seals, be sure to use the correct button head cap screws. DO NOT use any other type fastener.

3. Install the engine shaft adapter over the engine shaft, as shown in Figure 7.31 or 7.32. 4. Install the engine adapter bearing race, followed by the engine adapter bearing and the inner cam bearing race.

Refer to Figure 7.30. a. For ROLLER BEARINGS, the chamfered edge of the bearing races must face AWAY FROM THE BEARING

ROLLERS. That is, the flat (unchamfered) side of the race must ride against the rollers. b. For BALL BEARINGS, the bearing races are grooved to accept the bearing balls. MAKE SURE THE

BEARING BALLS ARE RIDING IN THE BEARING

RACE GROOVES. 5. Install the axial cam assembly. The factory-installed adapter has a built-in key which must engage with a keyway on the straight (non-tapered) engine shaft. Push the cam toward the engine until it seats against the engine adapter bearing race. 6. Again referring to Figure 7.30, install the outer cam bearing race, axial cam bearing and piston shoe bearing race. a. For ROLLER BEARINGS, the chamfered edge of the bearing races must face AWAY FROM THE BEARING

ROLLERS. That is, the flat (unchamfered) side of the race must ride against the rollers.

The inside diameter of the outer cam bearing race is larger than the piston shoe bearing race. b. For BALL BEARINGS, the bearing races are grooved to accept the bearing balls. MAKE SURE THE

BEARING BALLS ARE RIDING IN THE BEARING

RACE GROOVES. Piston Oil Seals and Pistons Refer to Figure 7.33 for this procedure.

Figure 7.33 — Oil Seals & Pilot Spacers

Item Name 1 Pilot spacer tang engaged in crankcase locating notch 2 Crankcase locating notch 3 Pump crankcase 4 High pressure oil seal 5 Pilot spacer

1. Pre-lubricate three (3) piston oil seals with 80W90 oil. 2. Press a seal into one of the piston bores provided on the pump crankcase, with the writing on the face of seal toward the installer. Press the seal in it bottoms. Repeat this step for the two (2) remaining seals. 3. Install the three (3) pilot spacers over the piston oil seals, as shown in Figure 7.33: a. Larger diameter flange of the pilot spacers must face downward (away from installer). b. Two small locating tangs on the pilot spacers must fit inside locating notch of the pump crankcase, as depicted in Figure 7.33.

Portable Pressure Washer Familiarization and Troubleshooting Guide Section 7 • Large Frame Pump

4. If the piston assemblies use a lock ring and have been disassembled, assemble them as follows: a. Install a retainer ring into the groove at one end of each piston. b. Slide the piston spring retainer up the piston until it contacts the retainer ring. Retainer must be installed exactly as shown in Figure 7.34. c. Springs are tapered. Install small end of tapered spring so that it contacts the spring retainer. 3. If the piston assemblies have an integral spring retainer ring, install the small end of the tapered spring so that it contacts the spring retainer.

Figure 7.34 — Return Spring Orientation

Item Name 1 Lock ring 2 Spring retainer 3 Return spring 4 Piston

4. Apply a small amount of SAE 80W90 oil to the lip of the oil seals and the piston surface. 5. With spring in place around piston as shown in Figure 7.34, install the piston through the crankcase, oil seal, and pilot spacer, as shown in Figure 7.35.

Figure 7.35 — Piston Installation

Item Name 1 Return spring 2 Pump crankcase 3 Piston oil seal 4 Pilot spacer 5 Piston

6. Install the thermal bypass piston and spring into the bore provided in the center of the pump crankcase, as shown in Figure 7.36.

Figure 7.36 — Thermal Bypass Components

Item Name 1 Pump crankcase 2 Thermal bypass spring 3 Thermal bypass piston 4 O-ring