Chevrolet 10 Series 1970 Service Manual page 296

BRAKES 5-58
9. Tighten the clamp rin g nuts and bolts even ly and only
su fficiently to elim inate leakage.
GOVERNOR (Fig. 1 00)
The govern o r, operating in conjunction with the a ir
com p ressor unloading m echanism , autom atically controls
a ir p ressu re in the brake system between the desired,
predeterm in ed maximum and minimum p ressu res.
a ir co m p re sso r runs continually while the engine runs
but actual com pression o f a ir is con trolled by the g o v e r ­
nor which stops o r starts com pression
Removal
If it is n ecessary to rem ove o r in stall a govern or, the
follow in g procedure w ill apply:
1. D rain a ir brake system .
2. Disconnect a ir lin es at g overn or.
3. Rem ove go vern or mounting
govern or.
Installation
1. Clean o r rep lace both a ir lin es
govern o r.
2. Mount g o vern o r in p lace with exhaust p ort pointing
tow ard the ground.
3. Connect a ir lines to govern or.
4. T e s t g o vern or fo r p ro p e r operation. (See Overhaul
Manual)
FOOT OPERATED AIR BRAKE CONTROL VALVE
The brake control va lv e connects through a le v e r to a
brake pedal. D epression o f the pedal m oves a plunger
and piston, closin g the exhaust va lve and opening the inlet
v a lve. This perm its a ir to flow past the in let va lve and
out the d e liv e ry p ort to the brake cham bers to apply the
brakes.
The amount o f fo rc e applied to the brakes is p ro p o r­
tional to the pedal p re ssu re applied by the operator.
Removal
1. Exhaust a ll a ir fro m system
2. R em ove a ll lin es running to brake valve.
3. Rem ove pedal push rod c le v is pin.
4. Rem ove mounting bolts and rem ove valve.
Disassembly (Fig. 101)
1. R em ove boot (18) fro m plunger (17) and bracket (16).
2. Rem ove plunger (17).
3. Rem ove mounting b racket (16) fro m v a lve body (10),
by rem ovin g 3 bolts (19) and lock w ashers (20).
4. R em ove snap rin g (15).
5. Rem ove piston assem b ly (14) and spring (11) fro m
va lv e body (10).
6. R em ove two seals (12 and 13) fro m piston assem bly
(14).
7. In vert va lve body.
8. Rem ove s c re w (1 ), reta in er (2), and diaphragm (3)
fro m exhaust va lve body (5).
9. R em ove ring (4) fro m exhaust va lve body (5).
10. Rem ove exhaust va lve body (5), seal (6), spring (7),
and va lve (9) fro m va lve body (10).
11. Rem ove seal (8) fro m va lve (9).
Cleaning and Inspection
1. ■ Check mounting flange fo r cracks o r breakage.
2. D iscard a ll rubber p arts.
The
b o l t s and rem ove
connected to the
3. Inspect the body fo r scorin g and ex ce s s iv e w ear. Be
sure a ll passages are c le a r.
4. Wash a ll m etal parts in non-toxic cleaning solvent
and dry with a ir.
5. Replace a ll parts found damaged o r worn.
Assembly (Fig. 101)
NOTE: Lu bricate a ll
grease o r equivalent.
1. P la ce seal (8) on va lve (9) and place in va lve body
( 10).
2. Install spring (7) on va lve (9).
3. P la ce seal (6) on exhaust va lve body (5) and install
assem bly in valve body (10) piloting on c o il spring
(7).
4. Secure exhaust va lve body (5) into va lv e body (10)
with ring (4).
5. Secure diaphragm (3) reta in er (2) to exhaust va lve
body (5) with screw (1).
6. In vert valve body (10).
7. Install se a l (13) on piston (14). Install seal (12) on
piston (14).
8. Install c o il spring (11) into va lve body (10).
9. Install piston assem bly (14) into va lve body (10) and
secu re with snap ring (15).
10. Secure mounting bracket (16) to va lve body (10) with
bolts (19) and lock washers (20).
F ig . 100— G o v e rn o r
s e a l s with Lubriplate
CHEVROLET TRUCK SERVICE MANUAL