2-12. AIR BRAKE SYSTEM TROUBLESHOOTING
TEST OR INSPECTION
1. AIR COMPRESSOR FAILS TO MAINTAIN SUFFICIENT AIR PRESSURE.
Disassemble air compressor cylinder head and unloader (page 3-466).
Check exhaust valves and seats for any damage that could cause
a. Replace exhaust valves and seats if worn or damaged (page
b. If exhaust valves and seats are okay, go to step 2 below.
Check cylinder head area where inlet valves are installed for
pitting or chipping.
a. If cylinder head is pitted or chipped in inlet valves area, re-
place cylinder head.
b. If cylinder head is okay, go to step 3 below.
Check exhaust valve springs for damage.
a. If exhaust valve springs are damaged, replace.
b. If exhaust valve springs are okay, go to step 4 below.
Check unloader plungers and associated bores in cylinder head for
presence of foreign matter.
a. If foreign matter present, remove.
b. If foreign matter not present, remove pistons (page 3-475) and
check piston rings for damage.
2. NOISY OPERATION OF AIR COMPRESSOR.
Remove air compressor if not already removed (refer to TM 5-3805-
From bottom of air compressor, check for broken or bent connecting
a. If connecting rods broken or bent, replace (page 3-475).
b. If connecting rods are okay, go to step 2 below.