TROUBLESHOOTING /SYSTEM PERFORMANCE Troubleshooting Ｄ-7. Bucket tilts forward with control valve in "Hold (Neutral)" state (front wheels cannot be raised off ground)
（１）Ch eck th e tilt cylinder for in ternal leakage .
Ch eck th e tilt cylinder for in ternal leakage . 1. Lower the lift arm to the lowest position and tilt back the bucket. 2. Disconnect the hose ① from the piston rod end (cylinder head) and close the disconnected end of the hose ① with the plug ② to prevent oil from spouting from the hose. 3. Start the engine and place the control lever in the "Tilt-back" position to apply oil pressure to the cylinder bottom end. 4. If oil flows out from the cylinder port ③ , the cause can be determined to be damaged piston seals in the cylinder. ԙ
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Repair th e tilt c ylinder. Ԛ
（２）Poor oil- tigh tne ss of overload relief valve
Chec k the overload relief valve for oil-tightn ess. 1 . Ch eck th at the fron t wh eels can be raised an d he ld off the grou nd by the tilt c ylin der. 2 . If fore ign matter is jammed into the overload relie f valve or the valve is in poor contac t with its se at, pre ssure fluid in th e piston rod e nd flow s directly to th e tank circ uit via the overload relie f valve, so the tilt cylinde r rod cannot be he ld in an extended position (front wh eels gradu ally low er). 3 . As the overload relie f valve s in the piston rod end an d cylin der bottom end are the same, fu nctionality of both the valves can be che cke d by in terc han gin g th em. 4 . If oil- tigh tness of th e c ylinder bottom end ove rload relief valve is de fec tive , th e b u c k e t s p o n t a n e o u s ly tilt s f o rw a rd . If oil-tightness of the piston rod en d overload relie f valve is defe ctive, th e f ro n t w h e e ls c a n n o t b e r a is e d a n d h e ld o f f th e g ro u n d . $QVVQO 'PF
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O il-tightn ess of the ove rload re lief valves is normal.
O il-tightness of the overload re lief valves is defe ctive.
Cle an or re place the ove rload re lief valve(s).
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