DEUTZ-FAHR FL35-70HP Series, Operation Manual

Page: 146 / 417

Electrical system
145
Fig. 4-20
1. Air reservoir assembly; 2. Air brake valve assembly; 3. Air compressor
The trailer brake system of FL35-70HP series tractor is a “inflation” control system. The trailer must be accordingly
equipped with a complete set of “inflation” control devices. For the trailer equipped only with an “inflation” control
system including the brake air chamber and controller, the “inflation” control system must be modified into
“deflation” control system ， which can be used for the trailer.
●
When the tractor is equipped with a trailer, observe the air pressure indicator. The air pressure of accumulator
shall not be less than 0.44MPa (4.5kgf / cm
2
), otherwise, increase the air pressure to the specified value before
the tractor moves off.
●
In normal times, the balancing air pressure in the accumulator shall not be less than 0.70MPa (7kgf /cm
2
),
otherwise, adjust the air pressure regulator. If air pressure gauge reading decreases rapidly when the engine
stops running, air leakage could occur. Identify and remove the cause promptly.
●
The Safety valve opening pressure of air reservoir shall be 0.75MPa-0.8MPa (7.5kgf /cm
2
-8kgf /cm
2
). Make
timely adjustment to the system in the case of air pressure gauge reading exceeding this range.
●
If the air reservoir pressure of tractor is normal, but the air reservoir pressure of trailer is low (indicated by
inefficient trailer brake), adjust only the adjusting screw to the left of brake valve.
●
If the air reservoir pressure is always in the range of 0.75MPa-0.8MPa (7.5kgf / cm
2
-8kgf/cm
2
) or a higher
range, the Safety valve is incapable of relieving load, and thus requires timely cleaning or replacement.
●
Before using the tractor-trailer combination, check its brake system. The brake system of trailer must operate
at the same time as, or a little earlier than the brake system of tractor. The brake system of trailer shall not
operate later than that of tractor. If necessary, adjust the adjusting screw of the brake valve to meet the above
requirements.
After connecting the male end of connector at the hose of trailer to the female end of connector at the back of trailer,
turn off the engine, and repeatedly depress and release the brake pedal, to check for air leakage at the connector.
Important:
The brake system of trailer must always operate a little earlier than that of tractor.