G2. Operational checks.indd seat (EN)

GROUP 2 OPERATIONAL CHECKS AND TROUBLESHOOTING GROUP 2 OPERATIONAL CHECKS AND TROUBLESHOOTING 1. OPERATIONAL CHECKS 1. OPERATIONAL CHECKS This procedure is designed so the mechanic can make a quick check of the system using a minimum amount of diagnostic equipment. If you need additional information, read structure and function structure and function, Group 1. A location will be required which is level and has adequate space to complete the checks. The engine and all other major components must be at operating temperature for some checks. Locate system check in the left column and read completely, following the sequence from left to right. Read each check completely before performing.

At the end of each check, if no problem is found (OK), that check is complete or an additional check is needed. If problem is indicated (NOT OK), you will be given repair required and group location. If verification is needed, you will be given next best source of information: Chapter 2 : Troubleshooting Group 3 : Tests and adjustments 4-29

Стр. 1

Hydraulic oil must be at operating temperature for these checks (refer to page 6-56). 4-30 Item Description Service action Parking brake capacity check Seat belt must be worn while doing this check to prevent possible injury when machine stops suddenly. Start engine. Fasten seat belt. Release parking brake and put transmission in 2nd gear forward. Drive machine at 8km/hr and switch parking brake ON. LOOK/FEEL : Machine must ON Release come to a stop within 2 meters (6 feet) when parking brake is P engaged at 8km/hr. Transmission must shift to neutral. OK Check completed. NOT OK Inspect parking brake. Go to group 3. Parking brake transmission lockout check Engine running.

Turn parking brake to ON. Place transmission in 1st forward. P Slowly increase engine speed to high idle. LOOK : Machine must not move. OK Check completed. NOT OK Go to transmission control circuit in section 3.

Стр. 2

4-31 Item Description Service action Service brake pump flow check ※ Hydraulic oil must be at operating temperature for the check. Engine OFF. Stop engine. Operate brake pedal approximately 20 times. Start engine and run at low idle. Record number of seconds required for low brake pressure indicator lamp to go out. LOOK : Indicator lamp must go out in less than 10seconds from time engine starts. NOTE : Indicator will not come on approximately 1 second after starting engine. OK Check completed. NOT OK Check for brake circuit leakage. Go to next page. IF OK Install a cap on line connected to inlet of brake valve and repeat pump flow check. If time does not decrease, check for worn brake pump.

Service brake capacity check Engine running. H M FFOL OK Check completed. NOT OK Check brake pressure. IF OK Inspect brake disk.

Стр. 3

4-32 Item Description Service action Brake accumulator precharge check ※The axles and hydraulic oil must be at operating temperature for this check. Start and run engine for 30 seconds. Stop engine and turn start switch to ON and wait 5 seconds. NOTE : Engine oil pressure lamp will be on due to no engine oil pressure. Count the number of times the brake pedal can be fully depressed before the low brake pressure warning lamp comes ON. LOOK : Warning lamp should not come ON in 1~5 applications. Start engine and operate at low idle. Observe cluster while applying brake pedal with maximum force. LOOK/LISTEN : Brake pressure indicator must not come ON. OK Check completed.

NOT OK Make sure brake pedal is not binding and keeping brakes partially engaged. Bleed brakes in group 3. Check brake system pressure. NOT OK If light comes ON with e n g i n e r u n n i n g , accumulator has lost it's charge. Inspect and recharge accumulator. Brake system leakage check Start engine and wait 30 seconds. Stop engine. Wait 2 minutes. Turn start switch to ON and wait 5 seconds. LOOK : Brake oil pressure warning lamp must not come ON within 2 minutes after stopping engine. OK Check completed. NOT OK I f b r a ke l e a k a g e i s indicated with brakes released, check leakage at accumulator inlet check valve and brake valve.

If brake leakage is indicated with brakes applied, check for leakage at brake valve and brake pistons. Check individual component leakage.

Стр. 4