2. Check and adjust front and rear tractor tirepressure to 25-30 psi (172-207 kPa).3. Check and adjust all castor tire pressures to 50psi (345 kPa).4. Check charge and counterbalance pressureswith engine at high idle using test ports definedin Hydraulic Systems Test Ports. Adjustcounterbalance setting to be 220 psi (1517 kPa)higher than charge pressure reading.5. Check for bent blades; refer to Checking for aBent Blade procedure in Mower Maintenance,page 51.6. Cut grass in a test area to determine if allcutting units are cutting at the same height.7. If cutting unit adjustments are still needed, finda flat surface using a 6 foot (2 m) or longerstraight edge.8. To ease measuring blade plane, raise theheight of cut to the highest position; refer toAdjusting the Height of Cut.9. Lower cutting units onto the flat surface.Remove the covers from the top of the cuttingunits.10. Loosen the flange nut, securing the idler pulley,to release the belt tension on each cutting unit.Front Cutting Unit SetupRotate blade on each spindle until the ends faceforward and backward. Measure from the floor tothe front tip of the cutting edge. Adjust 1/8 inchshims on front castor fork(s) to match height of cutto decal (Figure 26); refer to Adjusting the CuttingUnit Pitch procedure in Mower Maintenance,page 51.Figure 261. Castor wheel 4. Shims2. Tensioning cap 5. Axle mounting holes3. SpacersSide Cutting Unit SetupRotate blade of each spindle until the ends faceforward and backward. Measure from the floorto the front tip of the cutting edge. Adjust 1/8inch shims on front castor arm(s) to match heightof cut to decal (Figure 27). For the outside bladespindle only, refer to Adjusting the Cutting UnitPitch procedure in Mower Maintenance, page 51.27