TM 9-2330-203-14&P
4-31. BRAKE SYSTEM TESTS.
This Task Covers:
a.
Air Leakage Test
b.
Airbrake Chamber Pushrod Travel Test (Ml97A1
and M198A1)
Initial Setup:
Equipment Conditions:
Materials/Parts:
Intervehicular air hoses connected to towing vehicle
Tools/Test Equipment:
Personnel Required: Two
General mechanic's tool kit
a. AIR LEAKAGE TEST
1.
Coat air system lines and fittings with a soapy solution.
2.
Have assistant apply brakes in towing vehicle. Check air system lines and fittings for leaks. No leaks are
permissible.
3.
Tighten fittings to stop leakage. If leakage does not stop, replace tube assemblies and fittings (para 4-28, 4-29,
or 4-30). Intervehicular air hose air coupling leakage is usually caused by a worn, damaged, or improperly
installed preformed packing. Replace preformed packing (para 4-26).
4.
Coat exhaust check valve (M197 and M198) or exhaust port (M197A1 and M198A1) on emergency relay valve
with a soapy solution. Have assistant apply brakes in towing vehicle. Check for leaks. No leaks are
b. AIRBRAKE CHAMBER PUSHROD TRAVEL TEST (M197A1 AND M198A1)
1.With service brakes released, insert a small rod
(3) Y in. (3.2 mm) in diameter through inspection
hole in rear of airbrake chamber (1). Insert rod as
far as it will go and mark rod at surface of bracket
(2). Remove rod.
2.Have assistant apply brakes. Insert rod (3) as far
as it will go and mark rod at surface of bracket (2).
3.Remove rod (3) and measure distance between
marks on rod. Marks should be between X in. and
X in. (13 mm and 22 mm) apart. If marks are less
than X in. (13 mm) or greater than % In. (22 mm)
4.If brake adjustment is satisfactory but marks are
not within tolerance, replace master cylinder
FOLLOW-ON TASKS:
* Disconnect intervehicular air hoses from towing
4-76