Tractor

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Troubleshooting United States 816-891-2470

Guide
Mexico 52-81-81569500
 COMPLAINT/REMEDY COMPLAINT/REMEDY COMPLAINT/REMEDY COMPLAINT/REMEDY
COMPRESSOR SINGLE CHECK VALVE ABS INLINE VALVES RELAY VALVE
1 n PUMPS BEYOND “CUT-OUT”
- Check gauge.
7 n ALLOW BLEED BACK TO SUPPLY RESERVOIR 14 n FOR COMPLETE TROUBLESHOOTING INFORMATION REFER TO 19 n LEAKS AT EXHAUST PORT WITH ALL BRAKES RELEASED
- Periodic Test: bleed supply reservoir and observe gauges. Check valves - Check seal in spring brake for back flow of spring “hold-off” pressure
- Check governor. should maintain rear and front reservoir pressure.
MODAL POWER TK-2 INSTALLATION & SERVICE MANUAL AND/OR
- Be certain it pressurizes unloader port when above “cut-out”. through service port to open exhaust on valve. Replace #21 Spring
- Replace valve if results are negative. ABS DIAGNOSTIC TROUBLESHOOTING GUIDE @ haldex.com
Parking Brake.
- Check unloader/plungers. Lube, repair or replace head.
n
- Check reservoir port for evidence of contamination, check supply lines
WON’T PUMP AIR for rusty fittings or carbon deposits. Repair or replace.
- Check gauge.
- Check compressor drive. PRIMARY & SECONDARY RESERVOIR HAND CONTROL VALVE - TRAILER n LEAKS AT EXHAUST PORT WITH SERVICE BRAKES APPLIED
- Exhaust valve not seating properly. Repair or replace.
- Check inlet valves and plungers. If stuck, leak will be evident at intake
when unloaded. Install unloader kit, head kit or head assembly. 8 n EXCESS OIL/WATER
15 SERVICE BRAKES
n SLOW PRESSURE BUILD-UP - Drain as required. n LEAKS AT EXHAUST PORT WHEN RELEASED AND FOOT VALVE IS APPLIED
- Check gauge. - Check automatic/manual drain valve #6 on wet tank for - Check manifold style tractor protection valve #16. Replace if necessary.
- Check compressor drive. proper operation. QUICK RELEASE AND DOUBLE CHECK
- Check intake for restriction.
- Check discharge line for restriction.
n LEAKS AT EXHAUST PORT WHEN RELEASED AND TRAILER PARKING
BRAKES ALSO RELEASED 20 VALVE COMBINATION
- Check unloader function. Lube or kit. - Check anti-compound double check valve #20 for internal backflow n FOOT VALVE EXHAUST LEAK PARK BRAKES RELEASE YELLOW DASH
- Check inlet and exhaust valves. Leak will be evident at intake when AIR GAUGE into service control line, or trailer air system for backflow into tractor
9
CONTROL VALVE EXHAUST LEAK IN PARK POSITION AND SERVICE
unloaded. Repair or replace head. service control line. BRAKES APPLIED
n INCORRECT READING
n PUMPS EXCESSIVE OIL - Calibrate or replace. n LEAKS AT EXHAUST PORT WHEN RELEASED OR APPLIED AND ALL - Check anti-compound double check valve portion for feedback to foot
- Check oil return for restriction, kink or loop. PARKING BRAKES IN PARKED POSITION or dash control valve. Repair or replace.
- Check for gasket sealant obstructing drain. - Hand control valve is defective. Repair or replace.
- Check for undersize return line (1/2” minimum).
- Check for fitting restricting drain.
- Check for intake vacuum (20” water maximum). DUAL SYSTEM FOOT BRAKE VALVE MANIFOLD STYLE TRACTOR SPRING PARKING BRAKE (SERVICE ONLY
- Check for excessive engine crankcase pressure (poor engine ventilation).
- Check compressor ring wear. Exchange for service unit. 10 n LEAKS AT EXHAUST WITH ALL BRAKES RELEASED 16 PROTECTION VALVE WITH BUILT-IN 21 SERVICE CHAMBER SIDE OF SPRING
- Check anti-compound double check valve #20.
- Check anti-compound double check valve #20 for back flow into
DOUBLE CHECK VALVE BRAKE)
GOVERNOR
2 n FLUTTERS
- Check gauge.
service control line.
n CAUTION: CHOCK WHEELS.
n WILL NOT RESPOND TO TRAILER CHARGE VALVE
- Defective valve. Repair or replace.
n PARK BRAKE DRAGS OR WON’T RELEASE
- Check for: Improper adjustment, restriction or broken line. Diaphragm
- Check unloader line size (5/16” x 5’ maximum). n LEAKS AT EXHAUST WITH FOOT BRAKE APPLIED n SUPPLY LINE TO TRAILER WITH SLOW BLEED-DOWN DOES NOT SHUT failure. System pressure too low. Improper manual release. Broken
- Check air actuated accessory. Is the air volume requirement greater - Foot valve defective. Repair or replace. OFF TRACTOR AIR AND VENT BETWEEN 45 PSI AND 20 PSI return spring (spring side). Quick release of relay malfunction. Broken
than governor capacity? n LEAKS AT EXHAUST WITH ALL PARK BRAKES SET IN PARK POSITION - Check trailer charge valve #18, as it should “pop” to let T.P. valve power spring.
- Check for plugged governor reservoir line. vent trailer supply. Repair or replace. - Replace entire unit or piggy-back emergency section.
AND FOOT BRAKE RELEASED
- Repair, adjust or replace governor. - Foot valve defective. Repair or replace. n LEAKS AT EXHAUST PORT OR TRACTOR SERVICE (BACK THROUGH n SLUGGISH PARK APPLICATION
n WON’T PASS AIR TO UNLOADER TO “CUT-OUT” COMPRESSOR HAND OR FOOT VALVE) OR TRAILER SUPPLY - Check for: Diaphragm failure. Improper manual release. Broken power spring.
- Check governor reservoir line. - Defective valve. Repair or replace. n LEAKS WHEN PRESSURIZED FOR PARK BRAKE RELEASE
- Repair or replace. - Check for: Ruptured spring side diaphragm. Push rod seal leakage (may be
AIR DRYER
n FOOT VALVE EXHAUST PORT LEAKS WHEN HAND VALVE IS APPLIED
- Replace.
11
evident at relay valve #19).
LOW PRESSURE INDICATOR SWITCH n AIR LEAKING CONSTANTLY FROM PURGE VALVE n HAND VALVE EXHAUST PORT LEAKS WHEN FOOT VALVE IS APPLIED n SERVICE CHAMBER MALFUNCTION
3 n BUZZER OR LIGHT INOPERABLE.
- Check ground and wiring on switch and buzzer/light.
- Purge valve seal damaged. Replace. - Replace. u See service brake chamber #13.

- Purge valve frozen. n PERIODIC TEST: ALTERNATELY LOOSEN EACH INLET LINE AND
- Replace switch or buzzer/light. n HEATER INOPERATIVE APPLY PRESSURE TO OTHER. IF LEAK IS DETECTED, REPLACE.
n WON’T OPERATE AT PRESSURES BELOW 60 PSI - Blown fuse. Check fuse and replace with 8 –10 amp fuse.
- Check dash gauge for accuracy. - Broken wires or poor connections. Repair or replace wiring to heater.
- Replace switch or buzzer/light.
n SLOW WET TANK BUILD-UP LOW PRESSURE INDICATOR SWITCH
WET TANK - Filter and or desiccant plugged. Service air dryer.
17
4 n EXCESS OIL ACCUMULATION
n BUZZER OR LIGHT INOPERABLE
- Check ground and wiring on switch and buzzer/light.
- See PUMPS EXCESSIVE OIL (Compressor Section #1). - Replace switch or buzzer/light.
n EXCESS WATER ACCUMULATION
- Drain daily. Install automatic drain on wet tank.
QUICK RELEASE VALVE n WON’T OPERATE AT PRESSURES BELOW 60 PSI
n DAMAGED WET TANK
12 n LEAKS WHEN SERVICE BRAKES ARE APPLIED
- Check dash gauge for accuracy.
- Replace switch or buzzer/light. NOTE: FOR FURTHER TECHNICAL ASSISTANCE
- Replace. - Verify plumbing is correct. Possible supply and delivery
hoses are reversed.
CONTACT YOUR HALDEX DISTRIBUTOR, YOUR
SAFETY VALVE - Repair or replace. HALDEX SALES REPRESENTATIVE OR CALL
5 n ”POPS” OFF EXCESSIVELY. MANIFOLD DASH VALVE WITH BUILT-
(800) 643-2374 AND CHOOSE OPTION 2
- Check system pressure.
- Valve operating properly in venting at 140/150 PSI
18 IN TWO-WAY CHECK (RED OCTAGON)
SERVICE BRAKE CHAMBER TO SPEAK WITH A TECHNICAL ADVISOR.
- Check unloader/governor. TRAILER CHARGE (YELLOW DIAMOND)
n ”POPS” OFF AT LESS THAN 140 PSI
13 n LEAKS
TRACTOR PARK
- Replace. - Replace diaphragm.
n
- Cage park brake.
LEAKS - Reset clamps. n PARK BRAKE WON’T RELEASE
- Replace. - Adjust brakes.
n WON’T FUNCTION
- Check for full system pressure delivery through valve.
n WITH SERVICE BRAKES
- Periodic Test: remove and test above 150 PSI with shop air. APPLIED STROKE IS AT OR
n PARK BRAKE WON’T APPLY
- Replace if non-functional. BEYOND MAXIMUM LIMIT OF:
- Repair or replace, If it will not release pressure.
- Type 9 1 3/8”
n LEAKS AT EXHAUST PORT IN PARK POSITION SERVICE BRAKES APPLIED
MANUAL DRAIN VALVES - Type 12 1 3/8” - Check anti-compound double check valve #20.
6 n LEAKS
- Replace.
- Type 16 1 3/4”
- Type 20 1 3/4”
n LEAKS AT EXHAUST PORT IN PARK POSITION SERVICE BRAKES RELEASED
- Type 24 1 3/4” Brake - Repair or replace.
- Type 30 2” n WON’T APPLY TRAILER IMMEDIATELY WHEN “PULLED”
AUTOMATIC DRAIN VALVES n SLUGGISH APPLICATION OR
Released - Replace, if it won’t exhaust. Repair or replace anti-compound double check
n WON’T DRAIN RELEASE
- Check basic brake. valve #20 if air dryer #11 is functioning properly.
- Repair or replace.
n WON’T DRAIN IN COLD WEATHER
- Check for air line restriction/leak. n REAR TANK BLEED-DOWN ALSO BLEEDS FRONT TANK OR VICE VERSA
- Replace with heated unit. - Align linkage. - Periodic Test: Pressure should remain in one tank after the other is drained. haldex.com
- Check chamber return spring. Replace, if inoperative.
n LEAKS - MALFUNCTIONS - Adjust brakes. Angle should approach 90° on application. L20304 US 9/19 5M WAT
- Repair or replace. - Check for improper chamber or obstruction. Printed in the USA
- Periodic Test: with system pressure stabilized (compressor unloaded)
no leak evident at discharge port - make several foot brake applications
to reduce wet tank pressure. Moisture should drain from discharge port.