PUMP SYSTEM MALFUNCTIONS

MALFUNCTION

CAUSE

REMEDY

The Pressure and/

Worn packing seals

Replace packing seals

or the Delivery Drops

Broken valve springs

Replace springs

 

 

Belt slippage

Tighten or Replace belt

 

Worn or Damaged nozzle

Replace nozzle

 

Fouled discharge valve

Clean valve assembly

 

Worn or Plugged relief valve on pump

Clean, Reset, and Replace

 

 

worn parts

 

Cavitations

Check suction lines on inlet

 

 

of pump for restrictions

 

Unloader

Check for proper operation

Water in Crankcase

High Humidity

Reduce oil change intervals

 

Worn Seals

Replace seals

Noisy Operating

Worn bearings

Replace bearings, Refill

 

 

crankcase oil with recommended

 

 

lubricant

 

Cavitation

Check inlet lines for restrictions

 

 

and/or proper sizing

Rough/Pulsating

Worn packing

Replace packing

Operation with

 

 

Pressure Drop

Inlet restriction

Check system for stoppage

 

 

 

air leaks, correctly sized

 

 

inlet plumbing to pump

 

Accumulator pressure

Recharge/Replace accumulator

 

Unloader

Check for proper operation

 

Cavitation

Check inlet lines for restrictions

 

 

and/or proper size

Pump Pressure as

Restricted discharge plumbing

Re-size discharge plumbing to flow

Drop at gun Rated,

 

rate of pump

Pressure

 

 

Excessive

Worn plungers

Replace plungers

Leakage

Worn packing/seals

Adjust or Replace packing seals

 

 

Excessive vacuum

Reduce suction vacuum

 

Cracked plungers

Replace plungers

 

Inlet pressure too high

Reduce inlet pressure

High Crankcase

Wrong Grade of Oil

Giant oil is recommended

Temperature

Improper amount of oil in crankcase

Adjust oil level to proper amount

 

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Giant GP7128 service manual Pump System Malfunctions

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.

One of the main features of the Giant GP7128 is its lightweight aluminum frame, crafted from high-grade materials to ensure durability without sacrificing performance. This frame design contributes to an agile riding experience, ideal for both commuting and recreational cycling. The geometry of the GP7128 is carefully engineered to provide a comfortable riding position, minimizing strain during long rides while maximizing control and responsiveness.

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.

The Giant GP7128 boasts advanced tire technology, with puncture-resistant tires designed to withstand rough surfaces and sharp objects. This feature not only enhances the bike’s longevity but also gives riders peace of mind on longer rides. The wheels are built to be robust yet agile, allowing for quick acceleration and stable handling, making the bike a versatile option for city commuting or weekend adventures.

Another impressive aspect of the GP7128 is its ergonomic handlebars and saddle design. These components are specifically tailored to reduce fatigue, promoting a more enjoyable riding experience even on longer distances. Additionally, the bike is compatible with a range of accessories, including fenders and racks, making it an ideal choice for those looking to customize their ride for various purposes.

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.