Haldex air dryer troubleshooting

The troubleshooting tips below will help you keep your Haldex dryer working properly. Whenever you notice an unusual symptom (for instance, excessive compressor cycling or water in air system), check it in the table on this web page.
Haldex AB is mostly known as a manufacturer of brake, air suspension, and safety systems. The company based in Sweden has a yearly turnover exceeding 4.3 bn SEK and eight production sites in several countries from Germany and Sweden to China.

ProblemCauseSolution
Water in air system1. Desiccant contaminated (oil) or over saturated.1. Replace desiccant cartridge. Wipe dryer base dean. Check compressor for excessive oil passage.
2. Leaks in air system.2. Tighten air connections. Use soapy water to recheck for leaks following the Testing The ModulAir" Dryer Section.
3. Governor loose or not functioning properly.3. Check governor gasket for damage and replace if necessary. Reassemble governor and tighten governor bolts to recommended manufacturer's torque specifications.
Constant exhaust of air at air dryer1. Dryer unloader valve not closing.1. At compressor cut-out there must be a slight blow of regenerated air from the exhaust port of the dryer for approx. 20 -30 seconds. If air flow continues, after purge cycle, remove and inspect unloader valve of the dryer for obstruction or damage. If damaged, then replace. If obstructed or dirty, then clean and reinstall.
2. Governor loose or not functioning properly.2. Check governor gasket for damage and replace it if necessary. Reassemble governor and tighten governor bolts to recommended manufacturer's torque specifications 110-150 lb. in.
3. Compressor unloader not functioning (compressor not unloading).3. Repair or replace compressor unloader.
Excessive Compressor Cycling1. Excessive leaks in air system.1. Tighten air connections, soap connection and recheck for air leaks.
2. Broken, contaminated or defective unloader valve.2. Clean or replace compressor unloader valve.
3. Undersized compressor, duty cycle of compressor should not exceed 25%.3. Reduce air demand or use a compressor with greater air output.
Safety Valve Is Open1. Desiccant cartridge is plugged or overty contaminated.1. Excessive oil passage from compressor or high amount of carbon buildup. Check for worn compressor (piston rings, gaskets, etc) Replace desiccant cartridge.
2. Ice blockage inside air dryer.2. Check heater for proper functioning.
3. Excessive system pressure.3. Repair or replace governor.
Short Life Of Dryer Or Desiccant Cartridge1. Air at inlet of air dryer exceeds 170°F (77°C).1. Extend length of compressor discharge line. The (77°C) air dryer inlet temperature can usually be achieved with 12' to 15' of compressor discharge line.
Short Purge Cycle Of Air Dryer (Less Than 12 Seconds)1. Loose governor or poor gasket seal.1. Tighten governor bolts. If leakage still occurs, then replace gasket or complete governor.
2. Regeneration valve not functioning.2. Replace regeneration valve.