Table of Contents
Advertisement
Sec. 3
Page 42D
GM COACH MAINTENANCE MANUAL
BODY
6
1 Adjusting Screw
2
Lock Nut
3 Upper Spring Seat
4 Cover
5 Spring
6 Diaphragm and Lower
Spring Seat Assembly
7 Diaphragm Ring
8
Body
9
Valve
10 Valve Cap
11
Valve Spring
t)1
r - -
I
LJ
Outlet
~ - - - - ' 1 0
TP 4S08
Figure
14-Air Pressure Regulating Valve
pressed air, the regulator valve admits additional
compressed air, thus maintaining a constant pres-
sure of 17 pounds at the Grad- U -Stat.
Regulating Valve Adjustment (Fig. 14)
1.
Exhaust air pressure from air system.
Disconnect air line from regulating valve outlet
port and connect an air pressure test gauge to
this port.
2. Build up air pressura in air system and
observe reading on air pressure test gauge.
If
below or above 17 pounds, adjustment is required.
3. If pressure is above 17 pounds, back ad-
justing screw out a few turns, then loosen gauge
connection to bleed pressure down below 17 pounds.
4. Gradually turn adjusting screw inward until
gauge registers 17 pounds, then tighten adjusting
screw lock nut.
5. After maximum pressure (17 lbs) is reached,
gauge should show no further increase.
If
pres-
sure gradually increases, valve is not seating
properly due to worn valve or dirt on valve or
seat. Apply soap suds to vent hole in valve cover.
If
bubbles appear, diaphragm is leaking and must
be replace.
Regulating Valve Disassembly (Fig. 14)
1. Remove adjusting screw (1) and lock nut (2 ).
2. Unscrew cover (4) from body (8). Remove
spring, spring seats, diaphragm, and diaphragm
ring from body.
3. Unscrew valve cap (10) from valve body
(8) and remove valve (9) and spring (11).
4. Clean metal parts in suitable solvent and
wipe dry.
Wipe diaphragm and valve clean with
cloth dampened with cleaning solution.
5. Inspect diaphragm carefully.
If
cracked or
deteriorated, unscrew nut from diaphragm rod.
Unscrew lower spring seat from diaphragm rod
and remove diaphragm. Install new diaphragm on
rod, with smooth side toward tapered end of rod.
Install lower spring seat and nut on rod, tighten
each firmly.
Regulating Valve Assembly (Fig. 14)
1. Insert valve (9) into body (8) with rubber
seat in valve against seat in body. Install valve
spring (11) and valve cap (10).
2. Place diaphragm with lower spring seat (6)
on body with tapered end of diaphragm rod seated
in center of valve (9). Place diaphragm ring (7)
on top of diaphragm. Position spring (5) in lower
spring seat, with upper spring seat (3) on top of
spring.
3. Carefully place valve cover (4) over spring
(5) and thread cover onto body (8 ). Tighten firmly.
4. Thread adjusting screw (1) into cover, in-
stall valve in vehicle, and adjust pressure setting
to 17 pounds as directed under "Regulating Valve
Adjustment."
NOTE: When connecting air lines, apply
aviation type permatex to male threads,
but
DO
NOT
COAT
FIRST
TWO
THREADS.
UNDER FLOOR HEATER CORES, BLOWERS, AND
MOTORS
Heater cores, blowers, and motors are sus-
pended from coach floor in top of forward baggage
compartment, one on either side of aisle. Right-
hand motor and blower wheel rotate counterclock-
wise and left-hand motor and blower wheel rotate
clockwise, each blower forcing air through its
respective heater core into the air duct. Each
motor is secured to support bracket by four rubber
bushed mountings. Each blower wheel is secured
to its motor shaft by two hollow head set screws.
Blower wheels and heater cores are inclosed by
shells which direct the air flow through the heater
cores into the air ducts.
All joints in blower
and heater core enclosures are seaied.
Water
line connections at heater cores are made through
bolted flange type connectors.
Motors can be
disassembled, brushes replaced, and commutator
turned and undercut in accordance with established
practice. Do not turn commutator more than neces-
sary to obtain smooth surface.
Motor bearings
should be lubricated at intervals specified in
LUBRICATION (SEC. 13).
MAGNETIC SWITCHES AND CIRCUIT BREAKERS.
Under floor heater motor magnetic switches
and circuit breakers are mounted on rear side of
front spring rear bulkhead, and are accessible in
forward baggage compartment.
Magnetic switch
windings are connected in series with the high
Advertisement
Table of Contents
