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T51002 E
InstallatIon, servIce and troubleshootIng Procedures
PROBABlE CAUSES WITH RECOMMENDED fIX
As with the list of effects, one or more probable causes may apply. For each effect selected, choose the most
likely probable cause or ones that are easy to investigate first. Footnotes are located at end of table.
PROBABlE CAUSES
DESCRIPTION
RECOMMENDED fIX
1 System is
During normal operation, the indicator lamp
remains off if tire pressures are at or near target
pressure. Should tires lose air during trailer idle
time, the system will restore pressure at startup and
the indicator lamp will remain ON until target is
reached. See effect B.
Refer to HOW THE SYSTEM OPERATES on
page 9.
No action required
.
If the integrity of the indicator lamp is in question,
perform
the INDICATOR LAMP TEST on page 45 and
refer to the Electrical 5 section of this list.
leakage
2 Slow leak
A slow leak in a tire or elsewhere may cause the
system to frequently or continuously deliver air to
inflate tires.
The amount of air flow may not be
enough to turn on the indicator lamp
, but the
system will be able to maintain target pressure as
long as tank pressure is maintained.
I.
Check
tire for leaks from puncture, rim leaks, etc.
II.
Perform
CHECKING FOR AIR LEAKS on page 44
for tire hose and fittings.
3 Medium leak
Light on more than 10 minutes and intermittent. The
leak should be audible
.
This type of leak looses enough air out the system
to cause the indicator to come on, but the system
can still maintain tire pressures.
I.
Check
for system damage and obvious leaks.
II. If needed,
perform
III.
Repair
as needed.
4 Severe leak
Light on continuously, damaged tire or other
condition that allows maximum air flow. In this
case, the source of
the leak should be audible and
obvious
.
I.
Check
for system damage and obvious leaks.
II. If necessary,
perform
III.
Repair
as needed.
5 Leak at hubcap
assembly
Rotary union or other assembled components
in hubcap assembly may have worn or failed,
resulting in a leak or blockage. Leaking air pressure
in the wheel end and axle is vented at the axle vent.
Inspect and replac
6 Axle hose leak
Leaking air pressure in the axle is vented at the axle
vent. Most likely the leak is at an end fitting.
I.
Refer to
Figure 17 on page 19 to help
locate
and repair
II. Check fittings at both ends of the axle hose.
7 Tire hose leak
A leak in the tire hose can be the result of:
1. Over stretching
2. Hose catching on object while driving
3. Improper installation
4. Cut O-ring or gasket
Also refer to probable cause 18.
I.
Perform
CHECKING FOR AIR LEAKS on page 44
for tire hose(s) and fittings.
II.
Replace
the tire hose if:
a. Leaking or shows any evidence of damage.
b. O-ring is torn, distorted or is otherwise
damaged.
c. Threads are damaged, in which case the
hubcap may also need to be replaced.
8 Tire or rim leak
If the tire or rim leak is large enough, the wheel
valve will close and isolate the tire at the hubcap.
Refer to
IN THE EVENT OF A LEAK on page 44.
9 Manifold leak
(if included)
If your system has a manifold, it is a potential
source of leaks. For CP system, refer to Figure 36
on page 29. For PRO system, refer to Figure 39
on page 32.
I.
Perform
CHECKING FOR AIR LEAKS on page 44
for manifold hoses and fittings.
II.
Repair or replace
as needed.
10 Axle supply line/
fitting leak
These are the hoses and fittings that supply air to
both ends of the axle. For CP, refer to Figure 34
through Figure 36. For PRO, refer to Figure 37
through Figure 39.
I.
Perform
CHECKING FOR AIR LEAKS on page 44
for supply lines and fittings.
II.
Repair or replace
as needed.