5 - 3A - 1
SECTION 3A - PBR TANDEM BRAKE MASTER CYLINDER (AFTER 1/1/77)
SPECIFICATIONS
| Brake Master Cylinder Assembly | .... | . ... | . ... | PBR Tandem circuit with proportioning valve" | ||||||||
| Type | . . | ... | . ... | Dual reservoir, compensating type, without residual | ||||||||
| pressure valves. | ||||||||||||
| Bore | ... | .... | .... | .. . | .... | . ... | .... | 25,4 mm (1.00") | ||||
| Stroke - Total | .... | .. | 32,65 mm (1.28") | |||||||||
| Split - Front brakes | .... | , ... | .... | . ... | 58% | |||||||
| - Rear brakes | ... | .... | .... | 42% | ||||||||
| Displacement - Primary (rear brakes) . | .... | .... | 6,7 ml (0.41 in.') min . | |||||||||
| - Secondary (front brakes) | 9,2 ml (0.56 in.') min. | |||||||||||
| Recommended Brake Fluid . | . ... | . .. | Chrysler Heavy Duty Brake Fluid, (or any fluid | |||||||||
| conforming to DOT 3) | ||||||||||||
| * Proportioning valve not fitted to station | wagons with | |||||||||||
| PBR Slidin~ Head calipers. | ||||||||||||
| SPECIAL TOOLS | ||||||||||||
| E5C15 | ... | ... | ... | . .. | . ... | .... | . ... | Tool - Tube Cutting | ||||
| E5Cl5B | .... | .... | ... | . ... | . ... | Tool - Tube Flaring | ||||||
| TORQUE SPECIFICATIONS | ||||||||||||
| Nm | lb/ft | lb/in | ||||||||||
| Secondary piston stop bolt to master cylinder . | 7 | 60 | ||||||||||
| Safety warning switch | ... | 2 | 16 | |||||||||
| Proportioning valve end plug . | .... | . ... | 40 | 30 | ||||||||
| Master cylinder support bracket bolt | .... | .... | .... | 18 | 13 | 150 | ||||||
| Brake tube fittings to master cylinder | .... | .. . | . ... | 18 | 13 | 150 | ||||||
| Master cylinder to booster | 14 | 10 | 120 | |||||||||
| Reservoir attaching nut | .... | .... | . ... | . ... | 6 | 50 | ||||||
GENERAL INFORMATION
The PBR tandem master cylinder is of the compensating type with bolt on dual plastic reservoirs. The master cylinder consists of a front and rear pistons (in tandem), the front outlets actuate the front brakes. The rear outlet actuates the rear brakes.
Provision is also made for a brake failure warning light switch which is activated by a spool valve when a hydraulic failure occurs in either front or rear circuit.
MASTER CYLINDER OPERATION
The tandem master cylinder unit separates the front and rear brake hydraulic system. If one hydraulic system fails, the other, either front or rear, will operate to retard the vehicle.
Normal Operation
A feature of the master cylinder is an integral rear brake circuit proportioning valve which regulates the maximum pressure applied to the rear circuit. In the event of a front circuit hydraulic failure the proportion valve is bypassed allowing all available pressure to be transmitted to the rear hydraulic circuit.
When the brake pedal is depressed the primary piston moves forward compressing the primary return spring and simultaneously moving the secondary piston. This occurs because of the difference in spring tension between the primary and secondary piston return spring (the primary is stronger.)
REV. OCT. '78
"