Giant GP8155-R Valve Inspection and Repair, To Check Seals and Plunger Pipe, Description, Problem

GP8155-R PUMP REPAIR KITS

Plunger Packing Kit #09616				Inlet Valve Kit - #09587
Item	Part #	Description	Qty.	Item	Part #	Description	Qty.
38A	13286	O-Ring	6	51B	05078	Inlet Valve Seat	1
39A	05066	O-Ring	6	51C	05079	Valve Plate	1
40	07723	Seal Ring	3	51D	07658	O-Ring	1
42	05277	V-Sleeve	9	51E	05080	Valve Spring	1
				51F	05081	Valve Spring Guide	1
				56A	06258	O-Ring	3

Oil Seal Kit - #09584				Discharge Valve Kit - #09588
Item	Part #	Description	Qty.	Item	Part #	Description	Qty.
32	05058	Radial Shaft Seal	3	52B	05084	Discharge Valve Seat	1
33A	05056	O-Ring	3	52C	05079	Valve Plate	1
				52D/56A 06258		O-Ring	2
				52E	05080	Valve Spring	1
				52F	05081	Valve Spring Guide	1

GP8155-R TOOL LIST AND TORQUE SPECIFICATIONS

Item	Part #	Description	Torque Ft-Lbs (NM)	Tool Needed
17	05038	Hexagon Socket Screw	64 (87)	10mm Allen Wrench
24	05047	Connecting Rod Hex. Hd. Socket Screw	37 (50)	8mm Allen Wrench
33B	05054	Clip Ring	N/A	Industrial Snap Ring Pliers
36C	05062	Tension Screw	30 (40)	16mm Socket
49A	05073	Hexagon Nut (Manifold)	265 (360)	30mm Socket
51-52	05076-05082	Valve Assemblies	N/A	Valve Puller (p/n 07662) Included
				w/pump
58	05087	Hexagon Socket Screw	132 (180)	12mm Allen Wrench
K5	07381	Hexagon Socket Screw	N/A	8mm Allen Wrench

GP8155-R TROUBLESHOOTING

Problem	Cause	Solution
Pressure Drops, water leaks	V-sleeves leak	Replace V-sleeves, check surface of
		plunger
Pressure drops, pump gets loud	Discharge or suction valve leaks	Replace valve(s)
	Steam formation (Cavitation)	Reduce suction height, reduce flow
		resistance in inlet line, clean inlet
		filter, lower water temperature.
Irregular pressure	Worn Valves	Examine valves
	O-ring on valves or inlet valve
	adapter leaks	Examine O-rings, check valve
		casing for unevenness on the
		sealing surfaces
Oil leaks at visible part of plunger	Gear sealing is leaking	Examine seals and running surface
		of plunger

GP8155-R PUMP REPAIR INSTRUCTIONS

Valve Inspection and Repair

1) Remove socket head cap	2) Lift discharge casing	3) Take out pressure springs
screws (58)	(50B) up and away.	(57A). Pull out assembled
		valves (51 & 52) with valve puller.

4)Remove valve assembly (52) from discharge valve adapter (56) by gently twisting apart. The spring tension cap (51A, 52A) is screwed together with the valve seat (51B or 52B). Screw off spring tension cap. Takeout springs (51E, 52E) and valve plate (51C, 52C). Check sealing surfaces and O-rings (51D, 52D). Replace worn parts. Coat threads of valve seat with silicon grease or molycote anti-seize Cu-7439 when reassembling. Before refitting the valves, clean the sealing surfaces in the casing and check for any damage. Coat o-rings (51D, 52D & 56A) with silicone grease to help with re-assembly. Replace valve assembly (51) and pressure spring (57). Assemble valve assembly (52) to discharge valve adapter (56) by tapping together lightly with rubber mallet. While replacing the valve assemblies use a rubber mallet to tap the top of the valve puller lightly. This insures proper seating. Replace pressure spring (57A) and the discharge casing (50B). Tighten caps (58) at 133 Ft-lbs; check torque tension after 8-10 operating hours.

To Check Seals and Plunger Pipe

Dirty, milk-colored or frothy oil	Water has mixed with oil	Replace oil immediately, find & fix
		the cause
Oil leakage on the crankshaft	Shaft seal ring leaks	Check seal and shaft
Noise increases without the loss	Worn bearing	Dismantle gear, examine all parts,
		replace worn parts, check oil level. If
		service life was too short, check for
		excess strain or whether lubrication
		intervals were too long. Only
		specified lubricants are to be used.

5)Remove hexagon nuts (49A) and valve casing together with seal case (38) from crankcase (1). If necessary, carefully tap the valve casing (50) past the centering stud (50A) using a rubber hammer.

IMPORTANT! If necessary, support the valve casing by resting it on wooden blocks or by using a pulley.

6)Remove tension screw (36C) and take seal sleeve (39) together with all mounted parts out of the drive. Pull plunger pipe (36B) out of the seal assembly and check for any damage. Carefully, remove seal rings (40) and sleeves (42) with a screwdriver.

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