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Section 4 – Troubleshooting Information Hydraulic System
4.3 Hydraulic System
4.3-1 All Controls Inoperative
1. Broken or defective drive pump shaft or coupling. Check pump shaft and coupling. Replace if defec-
tive.
2. Hydraulic oil level low. Check oil level. Fill to proper level.
4.3-2 All Boom Functions Inoperative
1. Open or defective dump/ enable valve 2H-21A. Clean valve. Check O-rings on valve. Check opera-
tion of valve. Repair or replace valve as required.
2. Stuck or defective relief valve RV1. Set valve to specifications. Check O-rings and
clean valve. Repair or replace valve as required.
3. System pump P2 out of adjustment or is
defective.
Refer to section 5 for pump set up procedure. Re-
place if defective.
4. Defective load sense adjusting valve 3H-V2. Check valve. Replace if defective.
5. Defective pressure compensator valve 3H-V1. Check valve. Replace if defective.
6. Plugged or defective high pressure filter F1. Check filter. Replace if plugged or defective.
4.3-3 No Main Boom Up
1. Stuck or defective differential sensing valve
DSV2.
Clean valve. Check O-rings on valve. Check opera-
tion of valve. Repair or replace valve as required.
2. Stuck or defective lift up valve 4H-14. Clean valve. Check operation of valve. Repair or
replace valve as required.
3. Stuck or defective shuttle valve SV2. Clean valve. Check O-rings on valve. Check opera-
tion of valve. Repair or replace valve as required.
4. Stuck or defective check valve CV5. Clean valve. Check O-rings on valve. Check opera-
tion of valve. Repair or replace valve as required.
5. Stuck or defective counterbalance valve CB3. Clean valve. Check O-rings on valve. Repair or
replace valve as required.
6. Defective lift cylinder C1. Check seals on cylinder. Replace as necessary.
Replace cylinder if defective.
4.3-4 No Main Boom Down
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