GP7128 Repair Instructions

CAUTION: Don't loosen the 3 plunger (36) before the valve casing has been removed otherwise the plunger (36) could hit against the spacer pipe (51F) when the pump is being turned.

Seal life can be increased if the pretensioning allows for a little leakage. This assists lubrication and keeps the seals cool. It is therefore not necessary to replace seals before the leakage becomes too heavy and causes output and operating pressure to drop.

MOUNTING VALVE CASING

NOTE: Replace worn parts; grease seals with silicone before installing.

12.Check O-rings (38A) and support rings (38B) on seal case (38). Clean surfaces of seal sleeves in gear box and sealing surfaces of valve casing. Reassemble seal sleeve (39) by placing plunger (36) in seal sleeve; place pressure ring (41), v-sleeves (42), sleeve support ring (43), and tension spring

(45)over plunger (36). Place the seal case onto the seal sleeve and press into the crankcase, making sure that the weep hole on the seal sleeve is facing down. Tighten tensioning screw (36C) for plunger onto crosshead (25) with an open end wrench to 33 ft-lbs. (45NM)

13.Push valve casing carefully onto O-rings of seal case and centering studs (50A). Tighten nuts (49A) to103 ft-lbs. (140NM).

TO DISASSEMBLE GEAR

14.Take out plunger (36) and seal sleeves (39) as described above. Drain oil.

15.After removing the circlip ring (33B), lever out seal retainer (33) with a screw driver. Check seals (32,32A,33A) and surfaces of crosshead.

16.Remove crankcase cover (4). Loosen inner hexagon screws on the connecting rods (24) and push con rod halves as far into the crosshead guide as possible.

CAUTION: Connecting rods are marked for identification. Do not twist con rod halves. Con Rod is

to be

reinstalled in the same position on shaft journals.

17.Check surfaces of connecting rod and crankshaft (22). Take out bearing cover (14) to one side and push out crankshaft taking particular care that the connecting rod (24) doesn't bend.

CAUTION: Seal (32A) must always be installed so that the seal-lip on the inside diameter faces the

oil.

Reassemble in reverse order: Regulate axial bearing clearance - minimum

0.1mm, maximum

0.15mm-by means of fitting disc (20A). The crankshaft (22) should turn

easily with little

clearance. Tighten fitting screws (24A) to 30 ft.-lbs. (40 NM)

CAUTION: Connecting rod (24) has to be able to be slightly moved sidewise at the stroke journals.

GP7128 Torque Specifications

Position

Item#

Description

Torque Amount

24A

07616

Fitting Screw

30 ft-lbs. (40NM)

36

07664

Tensioning Screw

33 ft.-lbs. (45NM)

49A

13160

Nut

103 ft.-lbs.(140NM)

58

07699

Plug

156 ft.-lbs.(210NM)

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Giant service manual GP7128 Torque Specifications, Mounting Valve Casing, To Disassemble Gear

GP7128 specifications

The Giant GP7128 is a notable addition to the world of high-performance bicycles, designed for cycling enthusiasts who seek reliability and versatility in both urban settings and rugged terrains. This model embodies the commitment to quality and innovation that Giant is known for, making it a popular choice among riders of all levels.

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Equipped with a Shimano drivetrain, the GP7128 features a smooth-shifting gear system that allows cyclists to effortlessly navigate various inclines and terrains. The combination of a wide gear range offers optimal efficiency, ensuring riders can maintain speed and cadence regardless of the conditions. The bike's braking system is also noteworthy, featuring both front and rear disc brakes that provide reliable stopping power in all weather scenarios, enhancing safety on the road.

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In summary, the Giant GP7128 stands out with its lightweight aluminum frame, reliable Shimano drivetrain, powerful disc brakes, and puncture-resistant tires, along with ergonomic design features. This bike represents a blend of performance, comfort, and practicality, appealing to both casual riders and serious cyclists seeking a reliable vehicle for their outdoor pursuits. Whether navigating city streets or exploring nature trails, the GP7128 is equipped to deliver an exceptional cycling experience.