7.9 Possible failures in pneumatic system and guidelines for troubleshooting

Clogging or crumpling of brake control pipelines in one of the circuits or pipelines of main brake cylinders leveling valves Sticking of main cylinder pistons (does not go back in its initial position) due to piston cup and O-ring expansion, resulting in closure of compensating port by reason of use of incorrect hydraulic-brake fluid or ingress of mineral oil, petroleum, kerosene, diesel fuel into hydraulic-brake Sticking of main cylinder pistons due to piston cups expansion On tractors “BELARUS1822.3 /2022 .3» valve pistons stick due to O-rings expansion Clean or replace pipelines. Circulate hydraulicbrake fluid through the hydraulic system for forward motion and on tractors “BELARUS1822.3 /2022 .3” for reverse Rinse hydraulic drive system with hydraulic-brake fluid. Replace damaged cups and O-ring in the main and operating cylinders. Replace hydraulicbrake fluid. Circulate hydraulic-brake fluid through the hydraulic system for forward motion and on tractors “BELARUS-1822.3 /2022 .3” for reverse

Low efficiency of parking brake drive

Wrong adjustment of parking brake drive Adjust as specified in subsection 3.8.7 “Adjustment of parking brake drive”

7.9 Possible failures in pneumatic system and guidelines for troubleshooting

List of possible failures in pneumatic system and guidelines for troubleshooting are shown in Table 7.9. Table 7.9

Failure, external manifestations, cause Troubleshooting

Increase of pressure in balloon is slow

Air leakage from pneumatic system by the following reasons: - undertightened or damaged pipeline, fittings nuts, and coupling band

- damaged rubber gasket of coupling head - coupling head O-ring nut torque got loose - dirt entry under coupling head valve

- contact of dust cover with coupling head valve plug - faulty adjustment of brake valve actuator Detect leakages and correct them by retorque of junctions or replacement of damaged parts

Replace damaged gasket

Draw up the nut

Clean

Correct

Adjust brake valve actuator as indicated in clause 3.9.4.2 “Check and adjustment of single-line and

- impaired performance of pressure control valve - pressure control valve filter is clogged - faulty pneumatic compressor double-line pneumatic system brake valves” Dismount pressure control valve from tractor and send it to repair workshop Rinse pressure control valve filter

Contact your dealer

Increase of pressure in balloon is slow

Faulty pneumatic compressor Contact your dealer

Rapid decrease of pressure in balloon when the engine is stopped

Air leakage through coupling member of pneumatic system Stop the leakage

Rapid decrease of pressure in balloon when break pedal is depressed

Faulty brake valve Replace brake valve

Increased oil slobbering into pneumatic system by pneumatic compressor

Faulty pneumatic compressor Contact your dealer

insufficient air pressure in balloon

Faulty location of pressure control valve adjusting cap Adjust pressure control valve as specified in subsection 3.9.5 “Check and adjustment of pneumatic system pressure control valve” Faulty pneumatic compressor Contact your dealer

Table 7.9 finished

Failure, external manifestations, cause Troubleshooting

Pressure control valve engages compressor for idle stroke when pressure is below 0.77...0.80 MPa, and for operating stroke when pressure is below 0.65 MPa and over 0.70 MPa

Dirt accumulation in cavities and channels of pressure control valve Faulty location of pressure control valve adjusting cap Rinse and clear pressure control valve

Adjust pressure control valve as specified in subsection 3.9.5 “Check and adjustment of pneumatic system pressure control valve”

Damaged rubber parts of pressure control valve, spring shrinkage Replace damaged parts or send them to repair workshop

Tilting, deadlock of spool of adjusting part of pressure control valve

Ensure freedom of the spool movement, lubricate it or refer pressure control valve to repair workshop

Pressure control valve gets actuated frequently (engages pneumatic compressor) without air bleeding from receiver tank

Air leakage from pneumatic system or pressure control valve, failure of back-pressure valve Detect and stop the air leakages

Pressure control valve operates in mode of pressure-relief valve

Pressure control valve adjusting cap is turned for too much Adjust pressure control valve as specified in subsection 3.9.5 “Check and adjustment of pneumatic system pressure control valve”

Pressure control valve dummy piston seizure Disassemble pressure control valve and correct seizure