GAUGE AS-AUX 4717195 - Caterpillar

SAFETY RELIEF VALVEBrake Control Valve (Leakage Check)
Start the engine and allow the air pressure to build up.Depress the brake pedal and hold it in the depressed position. Coat air line connections at the air chambers with soap suds and check for air leakage. Release the brake pedal. Coat the exhaust port of the brake control valve with soap suds. Leakage must not exceed a 1 in. (25.4 mm) soap bubble in one minute. Correct any air leaks that may exist.Brake Adjustment
Caliper disc hydraulic brakes require no adjustment. There is no return mechanism to force the pads away from the discs; therefore, the pads remain in slight contact with the discs to keep them clean.Air In The Hydraulic Brake System
AIR CHAMBER AND MASTER CYLINDER (TRACTOR)
1. Bleed valve. 2. Air line. 3. Hydraulic lines. 4. Master cylinder. 5. Stroke indicator. 6. Air chamber.Air in the hydraulic brake system cannot be detected by brake pedal "feel." However, a stroke indicator on each master cylinder will provide a means of detecting a "soft" pedal condition resulting in increased master cylinder piston movement. If the movement of stroke indicator (5) is excessive, check for hydraulic leaks or air in the system. If the leak results from a damaged cup or seal the hydraulic brake system may be contaminated. Drain the brake fluid and flush the system with denatured alcohol. If the system is free of leaks, check for air. Bleed each hydraulic brake system. See the topic, LETTING AIR FROM BRAKES (Bleeding the Brakes).Brake System Test
Check of Operation
The indicator rod (1) will give an indication when brake repair is needed. With the brake pedal pushed down, make note of the stroke of the rod (1) on each master cylinder. Brake repair is needed when the indicator rod moves more than .75 in. (19.1 mm) from the air chamber of the master cylinder.
MASTER CYLINDER
1. Indicator rod.1. Start the diesel engine and let the air pressure in the reservoir go up to cutout pressure.2. Push the brake pedal down and keep it in that position.3. Look at the indicator rods (1). a. Slow movement of indicator rod after it has stopped once, is an indication that there is leakage in the hydraulic section of the brake system or that the cup is cut.b. Extra travel of indicator rod (with brake linings in contact with discs) is an indication that air is in the hydraulic section of the system.4. Release the brake pedal. a. If either one or both indicator rods do not retract, this is an indication that a bypass opening in one of the master cylinders is closed by dirt, corrosion or the primary cup has become too large. A primary cup which has become too large is an indication of wrong or dirty hydraulic fluid in the system. If hydraulic fluid is dirty, remove and repair all components in the hydraulic system of the brakes. Flush the brake lines with clean hydraulic fluid.Check for Leakage
1. Push brake pedal down and keep it in