Hummer H3. Manual — part 915

Review the Symptoms - Clutch and perform the necessary inspections.
Pedal blocked from full travel

1. Inspect for obstacles that prevent the

pedal from going to the floor.

2. Clear any obstacles from under the pedal

area, such as floor mats or interior
panels.

Excessive travel between pedal and clutch
master cylinder

1. Inspect the pedal for worn bushings.

2. Replace the pedal if the bushings are

worn. Refer to Clutch Pedal
Replacement.

Clutch pedal mounting loose

1. Inspect the clutch pedal mounting

bracket for loose or missing fasteners.

2. Replace or repair the fasteners. Refer to

Clutch Pedal Replacement.

Linkage at pedal worn or damaged

1. Inspect the linkage at the pedal for

excessive wear.

2. Repair or replace the linkage, as

required. Refer to Clutch Master
Cylinder Replacement.

Clutch master cylinder seized or binding

1. Inspect the master cylinder for the piston

being able to move freely and full range
of travel.

2. Repair or replace the clutch master

cylinder, as required. Refer to Clutch
Master Cylinder Replacement.

Air in the clutch hydraulic system

Bleed the clutch hydraulic system. Refer to
Hydraulic Clutch Bleeding.

Clutch actuator cylinder seized or binding

1. Inspect the clutch actuator piston for

moving freely.

2. Replace the clutch actuator cylinder if

the piston is binding. Refer to Clutch
Actuator Cylinder Replacement.

Clutch master cylinder leaking internally

1. Inspect for proper pedal reserve. Refer

to Clutch System Description and
Operation.

2007 Hummer H3

2007 TRANSMISSION Clutch - H3

2. Replace the clutch master cylinder if it

will not hold pedal reserve. Refer to
Clutch Master Cylinder
Replacement.

Damaged clutch assembly components

1. Remove the clutch assembly.

2. Inspect the following clutch assembly

components for damage:

Damaged clutch disc hub splines

Bent clutch disc

Bent drive straps

Broken or warped pressure plate

3. Replace the clutch assembly if any of the

above damage is found. Refer to Clutch
Assembly Replacement.

Excessive side loading on the release bearing

1. Inspect the following clutch system

components:

Worn or damaged pilot bearing

Excessive flywheel runout

Excessive engine to transmission
misalignment

2. Repair or replace any faulty

components.

Faulty pilot bearing

Replace the pilot bearing. Refer to Clutch
Pilot Bearing Replacement.

Transmission input shaft splines worn or
damaged

Replace the transmission input shaft. Refer to
Transmission Disassemble .

Tight or contaminated clutch disc splines

1. Clean the clutch disc and input shaft

splines.

2. If the clutch disc will not clean, replace

the clutch assembly. Refer to Clutch
Assembly Replacement.

Flywheel housing, engine block to clutch
housing or transmission front case
excessively misaligned

1. Inspect the transmission front case for

being faulty.

2. Replace the transmission clutch housing.

Refer to Transmission Disassemble .

2007 Hummer H3

2007 TRANSMISSION Clutch - H3

CLUTCH SLIPPING

Clutch Slipping

Grease or oil contamination on the clutch
discs facing

1. Repair the oil leak.

2. Repair the grease leak.

3. Clean the clutch disc facing and the

other clutch assembly components.

4. Replace the clutch assembly if it will not

clean. Refer to Clutch Assembly
Replacement.

Cause

Action

DEFINITION: The clutch does not engage completely after the pedal is released, after
shifting gears or the clutch slips during maximum engine loads, such as climbing hills or
high vehicle speeds. Clutch slipping is identified by increase in engine RPM without
increase in vehicle speed.
Review the Symptoms - Clutch and perform the necessary inspections.
Incorrect clutch pedal height, not allowing
the clutch master cylinder to return

Adjust the clutch release switch. Refer to
Clutch Pedal Cruise Control Release
Switch Adjustment .

Clutch pedal binding or sticking

1. Clear away any items that may be

contacting the pedal.

2. Inspect the pedal bushings for ease of

movement.

3. Replace the clutch pedal if it is faulty.

Refer to Clutch Pedal Replacement.

Clutch master cylinder binding or seized

Replace the clutch master cylinder. Refer to
Clutch Master Cylinder Replacement.

Clutch actuator cylinder binding or seized

Replace the clutch actuator cylinder. Refer to
Clutch Actuator Cylinder Replacement.

Kinked or damaged clutch hydraulic hose

1. Inspect for the correct routing of the

clutch hydraulic hose.

2. Route the hose properly.

3. Inspect for loose or faulty engine mounts

that may allow the hydraulic hose to be
kinked or pinched.

2007 Hummer H3

2007 TRANSMISSION Clutch - H3

CLUTCH GRABBING

Clutch Grabbing

4. Repair or replace faulty engine mounts.

Refer to Engine Mount Replacement
- Left Side and Engine Mount
Replacement - Right Side .

5. Repair or replace the clutch hydraulic

hose if it is damaged. Refer to Clutch
Master Cylinder Replacement.

Grease or oil contamination of the clutch disc

1. Repair the source of the oil leak.

2. Repair the source of the grease leak.

3. Clean the contamination from the clutch

components.

4. If contaminates cannot be removed,

replace the clutch assembly. Refer to
Clutch Assembly Replacement.

Worn or damaged flywheel

Replace the engine flywheel. Refer to Engine
Flywheel Replacement (w/Automatic
Transmission) .

Worn clutch disc facing

Replace the clutch assembly. Refer to Clutch
Assembly Replacement.

Burnt or glazed clutch discs

Replace the clutch assembly. Refer to Clutch
Assembly Replacement.

Input shaft splines worn

Replace the input shaft. Refer to
Transmission Disassemble .

Improper resurfacing of the flywheel

Replace the flywheel if it has been
improperly resurfaced, allowing contact of
the clutch disc hub or insufficient clamping
load of the pressure plate. Refer to Engine
Flywheel Replacement (w/Automatic
Transmission) .

Cause

Action

DEFINITION: The clutch grabs or chatters or the clutch is unable to release without the
vehicle jerking. An abrupt engagement of the clutch.
Review the Symptoms - Clutch and perform the necessary inspections.

2007 Hummer H3

2007 TRANSMISSION Clutch - H3