MODEL | 460, 461.217/219/227/229/238/239/249/266/267/302/321/322/323/326/327/328/329/331/332/335/336/337/338/341/342/345/365/366/367/368/392/401/402/403/404/405/450/451/452/454/455/456/458/459, 463 up to 5/31/12 |
ABS shown with EBD in model 463.308/330/331 |
5.04 | Vacuum reservoir (in fender) |
8.05 | Pilot pressure valve |
19. | Fixed caliper |
19.03 | Master brake cylinder |
19.05 | Wheel brake cylinder/rear axle |
27.04 | Brake unit |
34.02 | Expansion reservoir |
P42.00-0252-06
ABS shown with EBD in model 461.392 |
5.04 | Vacuum reservoir (in fender) |
8.05 | Pilot pressure valve |
19. | Fixed caliper |
19.03 | Master brake cylinder |
19.05 | Wheel brake cylinder/rear axle |
27.04 | Brake unit |
34.02 | Expansion reservoir |
P42.00-2181-06
General function
The vehicles are equipped with a hydraulic dual-circuit brake with vacuum support. For gasoline engines, the required vacuum for the brake unit is generated via the intake manifold vacuum; for diesel engines, it is generated by a vacuum pump.
A vacuum check valve is installed in the vacuum line on the brake unit in all vehicles.
At the front axle, disk brakes with 4-piston fixed calipers are used; at the rear axles, drum brakes in duo servo version are used.
The brake at the front and rear axles are adjusted automatically.
In case of brakes in forward travel, only the rear brake shoes of the rear axles are adjusted. Occasionally, to enable adjusting of the front brake shoes, the brake must be depressed completely a few times during reverse travel.
The pressure applied to the brake pedal is led through the piston rod to the dual-circuit master brake cylinder. The dual-circuit master brake cylinder is coupled with the tandem brake unit.
This increases the pressure applied by the driver. The increased pressure is led via the brake lines to the fixed brake calipers of the disk brake and to the wheel brake cylinders of the drum brake.
The brake pads of the disk brake are engaged by the pistons of the fixed brake calipers on the brake disk; the brake shoes of the drum brake are engaged by the pistons of the wheel brake cylinder on the brake drum.
If there is loss of vacuum, the driver must apply correspondingly high force when braking.
Otherwise the vehicle cannot be brought to a stop on time as the brake system without vacuum works like a hydraulic braking system.
Brake-circuit division
The brake circuit 1 works on both the fixed brake calipers on the front axle with 4 pistons each.
The brake circuit 2 works on the two wheel brake cylinders at the rear axle (except model 461.392) or on the four wheel brake cylinders of both rear axles (on model 461.392).
If one of the brake circuits does not work, the vehicle is braked only at one axle (except model 461.392).
On model 461.392, both rear axles are braked if the front-axle brake circuit does not work, and the front axle is braked if the rear axle brake circuit does not work.