Chevrolet 30 Series 1967 Service Manual page 274

BRAKES 5-60
Cleaning and Inspection
In most cases, major repairs on reservoirs are not
economical or practical. If a reservoir has been dam­
aged so as to be unfit for service, always replace it with
a new one.
In exceptional cases where the inside of a reservoir
has been coated with sludge that cannot be drained off it
can be removed with steam and hot water.
CAUTION:
Never plug up reservoir and apply
steam as serious damage will result. Under no
conditions should more than 150 PSI (steam
pressure) be applied to reservoir.
Testing
When testing for leakage, only water pressure should
be used. In this case only, higher than normal pressures
may be exceeded but only for a matter of seconds.
Installation
1. Install reservoir in place with mounting bracket nuts
and bolts. But do not tighten securely at this time.
2. Install drain cock and assemble and securely tighten
all air pressure lines.
3. Tighten reservoir mounting bolts and nuts and make
certain reservoir will not vibrate during service as
this will cause premature pressure line failure.
DRAIN COCKS
Removal
Apply wrench to the hexagon portion of the body only.
Unscrew and remove.
Disassembly
1. Push down on spring washer.
2. Remove key pin.
3. Remove spring washer, spring and key.
Fig . 94—S lack Adjuster Nut Lock Sleeve
PUSH LOCK SLEEVE IN TO
D IS EN G A G E HEAD OF W O R M
SHAFT TO MAKE ADJUSTM ENT
r'7-miy. p a re
' E W
LOCK SLEEVE MUST CO M E OUT
A N D E N G A G E HEAD OF W O R M
SHAFT TO LOCK ADJUSTM ENT
Cleaning and Inspection of Parts
Wash all metal parts in cleaning solvent.
If the key or body is badly scored, the complete drain
cock should be replaced.
Do not attempt to fit a new key in an old body or vice
versa.
Repairs
If slight leakage has been present due to a slight scor­
ing of the key or body, the key should be ground in with a
good grade of #400 grinding compound. Before the key is
again put in place, it should be given a light application of
a good grade of cup grease.
Assembly
1. Insert key in body.
2. Place spring and spring washer over key.
3. Push down on spring washer and insert pin in key.
Installation
Using a wrench on hexagon portion of drain cock, screw
in place.
SAFETY VALVE
Removal
Unscrew complete valve from line fitting.
Disassembly
Unscrew the spring cage (fig. 95) from the body of the
safety valve. Lift ball valve from body and remove
spring, spring seat, and release pin from spring cage.
Cleaning and Inspection of Parts
Clean all parts in cleaning solvent. Examine the ball
valve for signs of pitting or scratches. If any damage is
evident the safety valve should be replaced. Clean ball
STEM-
LOCK NUT-
EXHAUST
VALVE
SPRING
SEAT
BODY-
PORT OF
RESERVOIR
Fig . 95—Safety V a lv e
ADJUSTING
SCREW
SPRING
< ---------SPRING
CAGE
BALL
VALVE
CHEVROLET TRUCK SERVICE M ANUAL