BLADE AR 4240451 - Caterpillar

Location Of Scraper Air/Hydraulic Cylinder
(4) Air cylinder. (5) Brake master cylinder. (6) Brake fluid pressure (overstroke) switch.The two air cylinders are part of the air/hydraulic cylinders. Air cylinder (1) is installed (located) on the right side of the tractor frame in front of the axle housing. Air cylinder (4) is installed (located) on the rear of the scraper bowl frame inside and behind the left wheel.The air/hydraulic cylinder changes the energy of air under pressure into force and movement needed for brake application. The ratio of air pressure to brake fluid pressure is 1 to 16. [If the pressure at air inlet (13) is 70 kPa (10 psi), the pressure in the master cylinder (19) is 1100 kPa (160 psi).]When a brake pedal is pushed down, air under pressure goes from the brake control valve to inlet (13) of the air cylinder and pushes on piston (14). Piston (14) pushes on rod (15) which pushes on a piston in master cylinder (19). The rod is connected to the piston in the master cylinder.When the brakes are released, spring (8) returns the piston, rod and master cylinder piston to their original positions.If piston (14) comes in contact with indicator rod (9), rod (9) will move and open the overstroke switch. This will cause the brake fluid pressure indicator light to come ON. If this does happen, there is a problem in the hydraulic circuit for the wheel brakes. See the Testing and Adjusting section on Hot Or Dragging Brakes. After piston (14) comes in contact with indicator rod (9), the rod must be manually pushed back into the air cylinder to its original position.
Air/Hydraulic Cylinder (With Brakes Released)
(7) Air cylinder. (8) Spring. (9) Indicator rod. (10) Make-up fluid inlet. (11) Valve. (12) Bleeder screw. (13) Air inlet. (14) Piston. (15) Rod. (16) Power piston. (17) Valve insert. (18) Passage. (19) Master cylinder. (20) Fluid outlet.
Air/Hydraulic Cylinder (With Brakes Activated)
(7) Air cylinder. (8) Spring. (9) Indicator rod. (10) Make-up fluid inlet. (11) Valve. (12) Bleeder screw. (13) Air inlet. (14) Piston. (15) Rod. (16) Power piston. (17) Valve insert. (18) Passage. (19) Master cylinder. (20) Fluid outlet.Brake Master Cylinder Operation
The two brake master cylinders are part of the air/hydraulic cylinders. Brake master cylinders (2) and (5) are in the same locations as the air cylinders.Each master cylinder sends brake fluid to the wheel brakes on one axle. The brake fluid pressure in the master cylinder is 16 times the amount of air pressure in the air cylinder. Master cylinder (5) sends brake fluid to the rear axle and master cylinder (2) sends brake fluid to the front axle.Air pressure from the air circuit for the wheel brakes goes through air inlet (13) and moves piston (14) and rod (15) to the right. Rod (15) pushes on valve (11) and valve insert (17). Valve insert (17) closes make-up fluid inlet (10). More movement of rod (15) pushes power piston (16). The power piston pushes brake fluid in cylinder (19) through fluid