IMPORTANT
• The KUBOTA does not recommend the readjustment of relief valve. And KUBOTA will recommend the exhaust with genuine parts.
• As the HST may be damaged if the pressure is set to higher by mistake, be careful when adjusting it.
NOTE
• The relief pressure is set in between 33.4 to 36.2 MPa (340 to 370 kgf/cm2, 4840 to 5260 psi) when shipped from the factory. But, for the purpose of after-sales services, as it is impossible to reset the pressure precisely as set in the
factory, its setting range is defined as a slightly wider range between 31.4 to 35.3 MPa (320 to 360 kgf/cm2, 4560 to 5120 psi).
1. Measure the pre-adjustment distance A.
2. Compress the spring of the relief valve with a relief valve assembling tool (3). (See page G-49.)
3. Then, find the distance A by turning the poppet (4) with a screwdriver.
Reference: The distance A changes by about 1.5 mm (0.02 in.) per one turn of the poppet (4).
4. Repeat the same operation a few times to find the distance A as it is difficult to acquire at the first time.
5. After finding the distance A, hold the setscrew (6) to a vice and fasten the hexagon socket head screw (2) with specified torque. On this occasion, use a copper plate, etc. for the vice jaws not to damage the setscrew (6).
6. Install the relief valve in the HST.
7. Check the relief pressure as indicated in page 3-S10.
The distance A is for refresh only. Make sure to check the relief pressure after readjustment.
8. If the relief pressure does not fall within the readjustment pressure range, repeat the processes of the above item 1
onward.
Reference: The pressure changes by 1.5 MPa (15 kgf/cm2, 210 psi) per 0.1 mm (0.004 in.) in distance A.
