Chevrolet 70 1969 Series, Shop Manual

Page: 270 / 913

BRAKES 5C-77
TRU-STOP (DISC TYPE) BRAKE
This type brake is used only on models when
equipped with auxiliary transmission. The vent­
ilated brake disc is mounted between the propeller
shaft flange and the auxiliary transmission shaft
companion flange. Brake shoes are mounted in op­
posed positions with brake disc between, as shown
in figure 4. When brake is applied, the shoes are
forced against disc.
TRU-STOP BRAKE A D J U S T M E N T
Disc type brake should be adjusted before a
full brake application requires brake lever to be
pulled to travel limit.
1 Brake Support 8
Bracket 9
2 Parallel Adjusting 10
Screws 11
3 Front Lever Arm Pin 12
4 Pin Retaining Screw 13
5 Brake Cable Clevis 14
6 Brake Lever 15
7 Brake Shoe Pin 16
Retainer________________12.
Brake Shoe Pin
Front Brake Shoe
Rear Brake Shoe
Front Lever Arm
Brake Disc
Tension Spring
Spring
Rear Lever Arm
Adjusting Nut
Tie Rod
TPM-7639
Figure 4-Tru-Stop Type Parking Brake
1. Disconnect brake cable or rod clevis from
brake lever.
2. Tighten adjusting nut until spring exerts
enough pressure to bring lever against front lever
arm.
3. Insert a 1 /3 2 " shim between rear shoe lin­
ing and brake disc.
4. Tighten adjusting nut until front shoe lining
is firmly against disc, yet still allowing removal
of shim.
5. Make sure tension spring is in place. A d­
just parallel adjusting screws so that both linings
are parallel with disc. This provides 1 /6 4 " clear­
ance between front and rear shoe linings andbrake
disc at all points.
6. Make sure brake lever in cab isinfully re­
leased position. Adjust clevis on brake cable as
necessary to permit installation of clevis pin
through clevis and brake lever without changing
position of lever. Install clevis pin and cotter pin.
7. Make sure lock nuts on brake cable and ad­
justing screws are firmly tightened.
BR AKE S H O E R E M O V A L (Fig. 4)
1. Remove lock nut and adjusting nut from
tie rod. Remove tension spring.
2. Move lever in cab to fully applied position
so that rear lever arm can be swung clear of tie
rod. Remove washers and spring from tie rod.
3. Remove brake shoe pin retainer cap screws
and retainers. Remove brake shoe pins, then re­
move shoe and lining assemblies.
4. If shoe linings are worn down close to rivet
heads, remove old lining and install new lining.
Make sure that new linings are securely and even­
ly riveted to shoes.
BR AKE S H O E IN S T A L L A T IO N (Fig. 4)
1. Position brake shoes on lever arms and in­
stall brake shoe pins. Install brake shoe pin re­
tainers and cap screws.
2. Place spring and washers on tie rod. Swing
rear lever arm forward and insert tie rod through
hole in bottom of arm.
3. Move lever to released position and install
tension spring.
4. Install adjusting nut and lock nut. Adjust
brakes as directed under "Tru-Stop Brake Adjust­
ment."
STOPMASTER “FAIL-SAFE” BRAKES
Stopmaster "Fail-Safe" parking brakes are
not used as standard equipment on models covered
by this manual. When Stopmaster brakes with the
"Fail-Safe" feature are useda£ optional equipment,
no other parking brake system is required.
For all information relative to these brakes
refer to "Stopmaster Brakes" in "A IR B R A K E S"
(SEC. 5B) of this manual.
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SHOP M ANUAL