Pontiac FIREBIRD 1972 Service Manual page 292

4-6 1972 PONTIAC SERVICE MANUAL
,
TROUBLE DIAGNOSIS (Continued)
Remove test gage and plug intake port with fill valve
from J 22695 adaptor package.
Connect test gage to Superlift port and open air pres-
sure (95 psi). Move overtravel lever approximately 1"
up from neutral position, as measured from end of
lever.
Quickly move overtravel lever downward 2". At the
same time, begin timing number of seconds until air
begins to escape from exhaust port. This delay should
be 4- 18 seconds. Repeat check.
If either delay is not within specification, there has
either been a loss of silicone fluid or valve has lost its
adjustment due to damage or wear. Valve must be
replaced.
COMPRESSOR, RESERVOIR AND REGULATOR
-
LEAK TEST
Remove assembly intact.
Connect test gage to regualtor. Inflate reservoir
through service valve to 80- 110 psi.
Route an 8" piece of rubber hose between vacuum
and vent ports (Fig. 4-3).
While holding assembly in a vertical position with
reservoir end down, immerse in water until dia-
phragm is just submerged. Observe for air leaks at:
CAUTION: Do not submerge completely, as
water can enter around the cover gasket.
a. Reservoir weld seam.
b. Reservoir to compressor "0" ring. A stream of
bubbles may appear in this area and then cease.
Fig. 4-3 Checking Compressor, Reservoir and Regulator for
Leaks
The bubbles are caused by atmospheric air being
purged from air pockets in the second stage hous-
ing. If the bubbles stop, there is no leak.
c. Regulator to compress "0" ring.
d. Regulator boot--defective internal "0" ring.
e. Diaphragm between first and second stage
housings--tightening through-bolts may correct
the leak.
f. Service valve.
g. Test gage connections.
Remove hose from vacuum port and submerge dis-
connected end in water. Cover vacuum port with
finger. Do not permit water to enter through vacuum
port. If bubbles are evident, the probable cause is a
defective second stage housing check valve.
Correct any leaks by either tightening screws or re-
placing parts.
If the cover gasket area is inadvertenly submerged,
remove cover and tilt unit so that water may drain
through openings by distributor valve mechanism.
Move distributor valve from side to side until all
water is purged. Blow dry with compressed air, both
the distributor valve mechanism and interior of the
cover. Replace cover.
NOTE:
If the compressor passes this test, yet
fails the output test, the compressor, reservoir
and regulator needs to be overhauled.
HEIGHT CONTROL VALVE TEST-OFF CAR
Remove control valve from car.
Clean exterior of control valve thoroughly.
Connect test gage and air pressure source to intake
adapter and open air pressure (80- 1 10 psi).
Submerge unit in water. No air should escape if over-
travel lever is in neutral position. If bubbles escape
from Superlift port, replace control valve.
Shut off air pressure and detach test gage from air
intake port. Plug intake port with fill valve from
5-22695 adaptor package.
Connect test gage to Superlift port and open air pres-
sure.
With overtravel lever in neutral position, no air
should escape. If bubbles escape from exhaust port,
replace control valve.