Belarus 80.1 Operation Manual page 134

1 – pin; 2 – ferrule; 3 – brake valve; 4 – spring; 5 – link; 6 – nut.
Figure 3.8.2 – Adjustment of the pneumatic system brake valve drive
Carry out check and, if necessary, adjustment of the pneumatic system brake valve
drive in the following way:
1. Connect pressure gage with a scale not less than 1 MPa to coupling head
(with black cover) of the tractor pneumatic drive.
2. Start the engine and fill the cylinder with air up to pressure from 0,77 to 0,8
MPa as per the indicator of air pressure in the system, located on the dashboard. Kill the
engine.
3. Air pressure according to the pressure gage, connected to the coupling head
shall be not less than 0,77 MPa. If it is lower than specified carry out the following opera-
tions:
- check for a clearance from 1 to 2 mm between pin and upper edges of slots in
the levers, as shown in figure 3.8.2. If there is no clearance, unlock and remove
pin 1 and adjust length of link 5 by rotating ferrule 2;
- check and, if necessary, adjust compression of spring 4 up to a size from 36 to
38 mm (as shown in figure 3.8.2) by rotation of nuts 6 and lock them.
- carry out operations No1 and No2.
4. If after adjustments the air pressure according to the pressure gage, which is
connected to the coupling head, doesn't reach a value of 0,77 MPa, replace brake
valve 3.
ATTENTION: WITH BRAKE VALVE 3 PROPERLY OPERATING (FIGURE 3.8.2) AND
THE BRAKE VALVE DRIVE CORRECTLY ADJUSTED THE PRESSURE ACCORDING
TO THE PRESSURE GAGE, CONNECTED TO THE COUPLING HEAD (WITH BLACK
COVER), SHALL FALL TO ZERO WHEN SHIFTING INTERLOCKED BRAKE PEDALS
FOR A FULL SPEED OR WITH THE PARKING BRAKE FULLY ENGAGED!
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80-0000010B OM