INSTALLING A 691 SYSTEM

There are four steps to installing the 691 System.

1.Mounting

2.Plumbing

3.Wiring

4.Bleeding

The 691 System must only be installed by someone with good working knowledge of automotive brake and electrical systems.

It is important that the installer of the 691 System understands fluid types used in various 691 Systems. Read and understand this instruction manual before installing the 691 Brake Lock System.

Brake System Fluid

For all 691 installations the vehicle’s brake system fluid does not change. Vehicles currently using brake fluid in the brake system will continue to use brake fluid. Vehicles currently using mineral base hydraulic oil in the brake system will continue to use mineral base hydraulic oil.

691 System Fluid

The two 691 Power Unit designs, DOT 5 silicone fluid (SF) and mineral base hydraulic oil (HO), assure seal compatibility with your existing brake system.

NOTE: Power unit and brake system fluids do not become intermixed when a 691 System is installed. The 691 Actuator(s) isolate the 691 System fluid from the brake system.

BEFORE PROCEEDING:

1.Identify your vehicle brake system. See pages 3 & 4.

2.Be sure you have the correct 691 model number and it contains all the parts. Refer to Table 1 (pages 19 & 20).

All vehicles currently using automotive brake

fluid (DOT 3, 4, 5 or 5.1) in the brake system must use the 691 model numbers designated (SF). All vehicles currently using mineral base hydraulic oil in the brake system must use the 691 model numbers designated (HO).

3.Check brake pedal height and feel. With the vehicle running, push on the brake pedal until there is no more forward movement. Measure and record the distance from pedal to floor. Brake pedal height and "feel" will be the same after the 691 System is in- stalled, refer to Figure 4.

FIGURE 4

IDENTIFY YOUR BRAKE SYSTEM

Typical hydraulic braking systems in use today vary depending on manufacturer and size of vehicle. For in- stance, a vehicle equipped with a single system may have a firewall mounted booster or possibly a frame mounted remote booster. The same holds true for the dual and split systems. The rear wheel anti-lock system is a dual brake system with an anti-lock valve installed. All-wheel anti-lock systems are defined as 3-channel or 4-channel systems

(Check the number of outlet lines from the anti-lock control valve). To be absolutely sure which braking system your vehicle is equipped with, check it. Look for identifying features such as dual flex lines at rear axle or front wheels, number of master cylinder lines, anti-lock valve(s), etc. Then, compare with the circuits shown in Figures 5 thru 11.

Typical Single System

One single hydraulic system serving both front and rear brakes.

Identifying Feature:

1.One line from master cylinder.

691 Actuator Position:

 

(1) Front axle

(2) Rear axle

(3) 4-wheel

FIGURE 5

FIGURE 6

Typical Dual System (Vertical Split)

Two independent braking systems. One system leads to the front brakes and the other system to the rear brakes.

Identifying Feature:

1.Two lines from master cylinder. 2.Combination valve (used on some models).

691 Actuator Position:

 

(1) Front axle

(2) Rear axle￿

(3) 4-wheel

￿ Some imported vehicles use two separate air boosted master cylinders.

3