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Explanation Check hydraulic brakes by pumping the brake pedal three times before applying firm pressure to the pedal for five seconds. The pedal should not move. If it does, there may be a leak or some other problem in the braking system.
How do you test hydraulic brakes for their stopping action?
Test the hydraulic brakes (if equipped) by pressing the brake pedal three times, and then holding the pedal for 5 seconds; the pedal should not move. Move the vehicle forward and apply the parking brake. If the parking brake works, release it and test the service-brake stopping action.
Which three tests would you perform on a hydraulic system?
Often the only tests and actions performed on a hydraulic system involve changing the filters, sampling the oil and checking the oil level.
How do you test hydraulic?
Hydraulic Pressure Testing Circuit Filling the circuit with working fluid. Pressurizing the pressure line to the pressure line test pressure. Releasing the Pressure of the pressure line. Pressurizing the return and drain line to their respective test pressures.
How many red reflectors should you carry?
Cards In This Set Front Back What should wheel bearing seals be checked for? Hub oil level and no leaks Hub oil either laying in the rim or covering the rim. How many red reflective triangles should you carry? 3.
How do you do a DOT brake test?
Test Low Pressure Warning Alarm and/or Signal Turn the key to the on position. Rapidly apply and release the service brake pedal to reduce air tank pressure. The low air pressure warning signal must come on before the pressure drops to less than 60 psi in the air tank.
How should you check that your service brakes are working properly?
How should you check that your service brakes are working properly? Wait for normal air pressure, release the parking brake, move the truck forward slowly, and apply the brake pedal firmly. You just studied 70 terms!.
How do you check the brake chamber pushrod travel?
Pull the chamber push rod out to its limit by pulling on the slack adjuster arm or by prying with a short bar. If push rod travel is more than 3/4 in. (19 mm), brakes MUST be adjusted.
How do you test a hydraulic brake booster?
Turn the engine off, then repeatedly press the brake pedal slowly. When you pump it the first time the pedal should be very ‘low’— meaning not much pressure resistance. As you pump the pedal, the pressure should become firmer, which will indicate that the brake booster is not leaking.
How do you fix a hissing brake booster?
Remove the two bolts holding the master cylinder in place and pull it away from the vacuum booster. Then disconnect the push rod from the brake pedal. Next, remove the four bolts or retaining nuts holding the vacuum booster onto the firewall. Replace the vacuum booster with a rebuilt unit.
How do you diagnose brake problems?
8 Signs You Could Have Brake Problems Brake Light On. Squealing or Squeaking Noises. Grinding Noises. Wobbling or Vibration When Braking. Leaking Fluid. Spongy or Soft Brakes. Car Pulling to One Side When Braking. Burning Smells.
How do you find a hydraulic suction leak?
Check the suction side of the system for leaks. Pump seals, pipe fittings and unions are all possible areas for air leaks that allow the system to pull in air and pressurize it. You can find these leaks using an ultrasonic gun or by simply placing a small drop of oil or grease around the suspected leak site.
What would causes a hydraulic cylinder to leak down?
Leaks generally occur when the piston seals, holding valve, or rod seals wear out or are compromised due to various reasons. One cause of hydraulic cylinder drift is contaminated hydraulic fluid, which can damage seals and/or sealing surfaces.
How do you test hydraulic brakes for leaks CDL?
Test for hydraulic leaks: If the vehicle has hydraulic brakes, pump the brake pedal three times. Then apply firm pressure to the pedal and hold for five seconds. The pedal should not move. If it does, there may be a leak or other problem.
Where do triangles go when broken down?
As a rule of thumb, you should put the first warning triangle 10 feet directly behind your car on the side closest to the road. Then place the second warning triangle 100 feet behind your vehicle, lining it up directly in the middle of your car’s position.
What three emergency equipment must you have?
What three kinds of emergency equipment must you have? Spare electrical fuses, three red reflective triangles, properly charged and rated fire extinguisher.
What is stab braking method?
Explanation The stab braking method for emergency stops involves fully applying the brakes until they lock up. The brakes are then released until the wheels start rolling, and then the process is repeated.
When inspecting the brake assembly you should ensure CMV?
when inspecting the brake assembly, you should ensure: whenever a change of duty status is made, every three hours, or 150 miles, whichever comes first. after the initial 50-mile check, how often must you conduct additional on the road inspections of the cargo securement & securement deviices?.
How would you test if your brakes are working properly when stationary & when on the move?
Answer: Before starting the engine, press the pedal: The brakes should not feel spongy or slack. After starting, and immediately after setting off and finding a safe place to do so, the brakes should be tested by applying them firmly. The vehicle should pull up smartly without pulling to one side.
How do you know if your parking brake is bad?
There are a few symptoms to watch out for when your parking brake drum starts to go bad. Parking brake won’t hold. If you notice your parking brake will not hold, there may be a problem with the rear brake adjustment. Poor braking. Keep your parking brake working well.
