1374 / 1525
BRAKES
5
Bypass Valve
The Bypass valve is provided in the rear brake circuit
between Tandem master cylinder and LCRV. The
Bypass valve bypass the LCRV (Load conscious pressure
reducing valve) in rear only braking (i.e. front brake
failed) condition. The feedback of front brake line
pressure is provided to the Bypass valve. In case of
front brake failure, the low front line pressure being
sensed by the Bypass valve and the 100% brake line
pressure from TMC is applied on to the rear brakes
with out reduction in pressure.
The Bypass valve is located at RH long member of the
chassis (between pillar “B” and “C”) on vehicles with
ABS system as well as with non-ABS system. The
location of Bypass valve is changed to firewall area
only for vehicles with ABS system for improving brake
pipe layout.
Removal of Bypass valve
Unscrew the coupling nuts of front and rear brake lines
(Fig. 1). During replacement unscrew and remove the
Hexagonal bolts holding Bypass valve on mounting.
Remove Bypass valve assembly.
Installation of Bypass valve
Position the Bypass valve on the mounting bracket
(Ensure that the bleed screw is at top), screw in the
Hexagonal bolts. Tighten the Hexagonal bolts. Connect
the front and rear brake lines with the help of coupling
nuts, the tightening torque should be 1.4-1.8 kgm.
BLEEDING OF BRAKE ACTUATION SYSTEM WITH
BYPASS (ABS & NON ABS):
Bleeding has to be started first from the point farthest
from the master cylinder as per following order.
1 Bleeding of Rear Left Brake
2 Bleeding of Rear Right Brake
3 Bleeding of Front Left Brake
4 Bleeding of Front Right Brake
5 Bleeding of Bypass valve
Please note that 1 & 2 can be bled simultaneously if
possible. Similarly 3 & 4 can also be bled
simultaneously if possible.
BLEEDING OF BRAKE WITH ABS
For bleeding vehicles with ABS use TATA MOTORS
supplied ABS diagnostic software. Follow screen
instructions for bleeding and bleed bypass valve at the
end manually after all on screen instructions are over.
PLEASE NOTE THATWHENEVER FRONT CIRCUIT IS BLED,
BLEEDING AT BYPASS VALVE IS MANDATORY.
1.
Bleed Screw
2.
FromTandemmaster cylinder
3.
ToLCRV
Fig. 1
1
2
3
4
5
6
4.
To Rear Brake Line
5.
FromFront Brake Line
6.
FromLCRV