Hitachi 4043 Servicing the Seals and V-Packings, Reassembly, Servicing Crankcase Section

Pump Service

Servicing the Seals and V–Packings

Disassembly:

1.Remove the manifold as described.

2.With crankcase side of manifold facing up, unscrew the seal case from the manifold using a special key wrench.

3.Remove o–ring from seal case.

4.Remove snap ring and low pressure seal from the seal case. Seals are generally removed easily without any tools.

5.High Pressure Seal Models: The high pressure seal is generally easily removed from the manifold without any tools. If extremely worn a reverse pliers may be used.

6.V–Packing Models: The female adapter, two v–packings and male adapter are easily removed from manifold without tools. If extremely worn a reverse pliers may be used.

Reassembly:

V–Packing Models:

1.Lubricate high pressure packing area in manifold.

2.Insert male adapter with notches down and “v” side up.

3.Lubricate v–packings and install one–at–a–time with grooved side down.

4.Next install female adapter with grooved side down.

5.Examine seal case o–ring and replace if worn. Lubricate new o–ring before installing.

6.Thread seal case into manifold and tighten with key wrench.

High Pressure Seal Models:

1.Lubricate seal area in manifold.

2.Carefully square seal into position by hand with the metal grooved side up.

3.Examine seal case o–ring and replace if worn. Lubricate new o–ring before installing.

4.Next secure high pressure seal into position by threading seal case into manifold. Tighten seal case with key wrench.

Low Pressure Seal–All Models:

1.Examine seal for wear or broken spring and lace if necessary.

2.Install low pressure seal in seal case with garter spring down.

3.Reinstall snap ring. Be certain snap ring is a tight fit. Replace if it can be easily turned.

4.Replace manifold on pump as described and torque per chart.

Servicing Crankcase Section

1.While manifold, plungers and seal retainers are removed, examine crankcase seals for wear.

2.Check oil level and for evidence of water in oil.

3.Rotate crankshaft by hand to feel for smooth bearing movement.

4.Examine crankshaft oil seal externally for drying, cracking or leaking.

5.Consult factory or your local distributor if crankcase service is evidenced.

Torque Chart

Pump Part	Thread	Tool Size	Torque
Plunger	M5	11 mm hex	80 in. lbs.
Retainer
Manifold	M8 x 1.25	13 mm hex	125 in. lbs.
	M10 x 1.25	17 mm hex	217 in. lbs.
	M10	17 mm hex	217 in. lbs.
Valve	—	24 mm	75 ft. lbs.
Covers		27 mm	75 ft. lbs.

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