GMC 4000 Series Service Manual page 461

Sec. 7D
Page 450
CLUTCH CONTROLS
Figure 6 — Clutch Hydraulic System ("L" M odels)
3. Make sure return spring at release fork
is not weak or broken.
4. Check, and if necessary, adjust clutch
linkage.
5. If clutch pedal action is springy or spongy,
it is an indication that air needs to be bled from
hydraulic system .
A specified clearance at two points in the
Figure 7 — Access to M aster Cylinder (" L" M odels)
G M C S E R V I C E M A N U A L
1 M a ster C ylin d er
2 Push Rod Boot
3 M a ster C ylin d er Push Rod 11 Pedal (L o w er Section )
4 Push Rod L ock Nut
5 L e v e r -to -S h a ft C lam p Bolt 13 S le e v e A ttaching S c r ew s
6 S p ecia l S p a cer
7 Pedal Shaft L e v e r
Pedal R eturn Spring
8
hydraulic control linkage is necessary for proper
operation. One adjustment is made between the
master cylinder piston and the end of foot pedal
push rod.
the
Adjustment."
the proper operating length of the slave cylinder
push rod down at the clutch. This adjustment is
referred to as the "Slave Cylinder Push Rod
Check and Adjustment."
and adjustment must be performed before the
slave cylinder check and adjustment. Also, before
making either adjustment, make sure that level
of fluid in master cylinder is 1/2 inch below the
top of reservoir. The fluid system must be free
of air.
models is gained after removing sm all access
9 Pedal A ttaching Bolt
10 Pedal (U pper Section )
12 Pedal Stop (Bum per)
14 S le e v e and Bushing A s s y .
15 L u b rica tion F ittin g
Figure 8 — Clutch Pedal and Linkage ("L" Models)
This adjustment is referred to as
"Master Cylinder Push
The other adjustment is made by obtaining
IMPORTANT: The master cylinder check
A ccess to master cylinder filler cap on "L"
-9985
tpm
Rod Check and