Bleeding the brake systems


Bleeding the main brake systems



A male connector (3) fitted as standard on the charge and lubrication line (5 bar) of the right-hand hydraulic cover plate and the male connector (10) installed as standard on the brake master cylinders with oil tank (B) or without oil tank (A) must be used to facilitate the bleeding under pressure of the brake system.
Make a hose (2) for couplers whereby:
- one end is installed with a female connector suitable for attachment to the male connector (10) (bleed assistance) of the brake master cylinders 


- the other end is installed with a female connector suitable for attachment to the male connector (3) (5 bar lubrication and charge) of the right-hand hydraulic cover plate.


Connect a transparent pipe (T) to each bleed screw (1) (right and left) of the centre housing.


Dip the ends of the two pipes into the oil filling pipe of the housings, without immersing them too deeply.


Conveniently locate the brake master cylinder return hose (1). Using a clamp installed with protective jaws, pinch this hose without flattening it excessively. If the structure of the pipe/hose assembly is too rigid, disconnect it by unscrewing just the pipe (t) connected to the connector (10) via the T connector. Temporarily screw a locally obtained plug onto each disconnected section.
Start the engine. Stabilise its speed at approximately 1300 rpm. Bring the oil to operating temperature.
Open the two bleed screws by approximately one turn. Wait approximately 5 minutes.
Pedals coupled
Fully press down and slowly release the pedals about 8 times until the oil flows free of air bubbles.
Pedals uncoupled
Fully press down and slowly release each pedal about 8 times until the oil flows free of air bubbles.
Pedals coupled
Fully press down and slowly release the pedals about 5 times until the oil flows free of air bubbles.
First close the left-hand bleed screw which is the furthest away from the brake master cylinders. Then close the right-hand bleed screw.
Press very hard (approximately 60 to 80 kg) on each pedal to correctly position the brake pistons.
Check the hardness under force of each pedal. Coupled pedals should not travel more than 120 mm for the force stated above.
If an operating problem emerges, carry out the bleed sequence a second time. If the problem remains, switch off the engine and check the sealing of:
- the system;
- the master cylinders;
- the brake piston seals.
Remove:
- the local hose (2) for couplers 


- the clamp fitted to the pipe/hose assembly (1). If a clamp has not been used, unscrew the locally obtained plugs. Reconnect the pipe (t) to the T connector of the connector (10).

Bleeding the trailer brake system

If the tractor is Installed with a trailer brake mechanism (FTE valve (14) and priority block (16), it is strongly recommended to bleed the main brake and trailer brake systems simultaneously.


Open :
- the two screws (1) of the main brakes;
- the trailer brake screw (2).


When the bleeding is complete, tighten in the following order :
- the left-hand bleed screw (1)
- the right-hand bleed screw (1)
- the trailer brake bleed screw (2)


• Check the trailer brake pressure on the quick coupling located at the rear of the tractor. If this pressure is not correct, eliminate any air entering in the system. Repeat the bleeding procedure.
• Carry out a road test.