REMOVAL & INSTALLATION
Screw-in proportioning valves can be identified by numbers stamped on the body of the valve. Be sure to replace with the correct numbered valve. Proportioning valves should never be disassembled.
- Raise vehicle on jackstands or position vehicle centered on a frame contact hoist.
- Disconnect and remove both battery cables from battery.
- Remove the battery hold-down clamp and battery from battery tray.
- Unfasten the 2 bolts attaching battery tray to battery tray support bracket and frame rail. Remove battery tray from vehicle.
- Unfasten the bolt attaching CAB to battery tray support bracket, and remove CAB from battery tray support bracket.
The CAB does not require removal from vehicle when servicing the modulator assembly.
- Loosen but do not remove (bracket is slotted) the bolt attaching the battery tray support bracket to the modulator assembly mounting bracket.
- Loosen but do not remove the bottom bolt, (bracket is slotted) attaching the battery tray support bracket to the side of the frame rail.
- Loosen the top bolt attaching the battery tray support bracket to the side of the frame rail. Remove the battery tray support bracket from the vehicle.
- Remove the acid shield, from the ABS modulator assembly.
- Remove the brake tube from the proportioning valve.
- Remove the proportioning valve from the modulator.
- Lightly coat the proportioning valve to modulator sealing ring with fresh clean brake fluid.
- Install the proportioning valve into the modulator assembly by hand, until the O-ring seal is fully seated against the modulator assembly, then using a crow foot, tighten the proportioning valve to 26 ft. lbs. (35 Nm).
- Install the hydraulic brake line on the proportioning valve and hand start the tube nut into the proportioning valve. Tighten the tube nut to 13 ft. lbs. (18 Nm).
- Using approved jumper cables, attach the battery to the vehicles negative and positive battery cables.
- Bleed the vehicles base brake and anti-lock brake hydraulic systems as outlined in this section.
- Install the acid shield onto the modulator assembly. Be sure acid shield is securely attached to the modulator assembly before installing the battery tray support bracket.
- Install the battery tray support bracket in the vehicle. Fasten the 1 bolt attaching support bracket to frame rail and tighten the 3 bolts attaching the battery tray support bracket to the frame rail and the modulator bracket to 125 inch lbs. (14 Nm).
- Install the CAB module/mounting bracket assembly, on the battery tray support bracket. Fasten the CAB assembly mounting bolt and tighten to 14 inch lbs. (6 Nm).
- Install battery tray. Then install the 2 bolts mounting battery tray to battery tray support bracket and fender shield.
- Install battery on battery tray.
- Install and securely tighten battery hold down clamp.
- Install battery cables on battery. Securely tighten clamping bolts on battery cable terminals.
- Reset any electrical components of the vehicle which were affected by the removal of the battery.
- Road test vehicle to verify correct operation of the vehicles's base and Anti-lock brake systems.