Answer: Either the brake pads need to be replaced, or you could try shaving off the leading rear edge of the brake pad at a 45-degree angle and see if that helps. Technician A says the quick take up valve must be depressed. Correct answer B-The short push rod length has to travel farther to make contact. b. VAV_\text{A}VA and I2I_2I2? Technician B says air trapped in the hydraulic system could be the cause. Tech A states that in the Traction Control System, the control unit can independently apply individual brake units even though the driver is not stepping down on the brake pedal. What do you think it might be? The caliper can also freeze up if the caliper slide pins have lost lubrication because they have not been maintained properly. Unusual brake pedal feel. Technician B says the new rotors should be indexed to the hub using a dial indicator for the least amount of runout. B only Second, it can act like a check valve. Correct answer D-Both technicians are wrong because the problem is in the power booster. measure the pad-to-caliper piston clearance. 3 Basic Kinds of Valves in a Non-ABS System. If there is fluid, but it is below the full indication, that may indicate that the friction material on the pads or shoes,or the rotors or drums themselves, may be worn beyond effectiveness. Checking the diagnostic trouble codes is possible. ASE identifies suspension both . Eventually, a sticking brake caliper will wear down the brake pads. Another uncommon cause of a soft pedal and long travel, is a bad wheel bearing, which is unrelated to the brakes except for being in the vicinity of the rotors. Correct answer D-Air causes a gap in the hydraulic fluid flow because the fluid has to compress the air before it can apply the piston. A spongy brake pedal on a vehicle with 4-wheel disc brakes with a longer than normal travel indicates which of the following? When that happens, I release the brakes and apply them again super fast. If the master cylinder is leaking externally, you will see fluid dripping from the place where the rod goes into the cylinder. The consent submitted will only be used for data processing originating from this website. 4-wheel disc brakes on a vehicle are causing brake squeal. One safe way to test whether a braking problem is at the front or rear brakes is to drive at a low speed and: (7.1.2) *, All of the following can cause brake pedal pulsation, EXCEPT, All of the following can cause brake system dragging, EXCEPT. Technician B says that the star wheel assembly should be lubricated on the floating end. If you are trying to bring a project car back to life, but can't get it to roll, chances are this is the problem. Correct answer A-The engine must be off to deplete the vacuum reservoir to test the booster. Brake dust is best removed from brake components on the vehicle by using: If a retracting tool is not available, which of the following can be used to retract the pistons in a caliper with non-integrated parking brakes? If you have this type of rear braking system, it is almost impossible to isolate the rear brakes. B only During brake application pressure is high enough to bypass the kink, but when the brake pedal is released, the spring pressure of the master cylinder is not sufficient for the pressure to bypass the kink. Soft Pedal- The brake pedal is easy to push but there is less braking. Every rotor has a "minimum spec" for thickness, usually stamped on the rotor near the hub where the lug nuts are. Which of the following can cause brake pedal pulsation? B. loosening the bleeder screw on the accumulator with the ignition switch on a. VAV_\text{A}VA and I1I_1I1? A. A restricted disc brake caliper hose might cause all of these EXCEPT: We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development. Brakes, when applied must not disrupt steering geometry. Answer: It is most likely either a blockage in the line or a worn brake master cylinder. You could also have a ballooning brake hose when the brakes are applied. The master cylinder, where it attaches to the brake pedal. Use the relative acceleration method to graphically determine the linear velocity and linear acceleration of the piston. residual valve is used to hold pressure against the . This leads to excessive pedal travel. Technician A believes it's a defective proportioning valve issue. A slight gap should be present between the pushrod and the master cylinder. 8. When another fluid, other than brake fluid, is added to the brake system, the two fluids mix and a detrimental act begins to occur in the system. A stuck brake caliper can cause the pads to be pressed against the rotor while driving. Here are five of the most common brake problems I run into, starting with the most serious. Your brakes pull to the good side. b. The steering wheel vibrates all the time and always veers to the left. Question: My brakes squeak only when I back up. Or it's possible your brake booster push rod is out of adjustment. Brake fluid reservoir. The wheel cylinder is attached to the ________. Hydro boost locking up breaks | Diesel Place D. Low brake fluid. c. Parking brake out of adjustment Don't drive the car in any case; there is something wrong with your brakes if the pedal is soft. Replace them if you see that they have oil, fluid or grease on them. C. 200200200 Always use OEM recommended clips and anti-squeal shims. Question: My car has power brakes and used to stop on a dime. Be sure to remove the pad shims from the caliper and check for any rust under the shims as rust can cause the pads to bind. The braking systems commonly found on modern vehicles are composed of several components that work together to slow and stop the vehicle. If it the booster, check valve, or vacuum hose is bad, it will likely also cause a vacuum leak and rough engine idle as well, but an engine with a bad valve or head gasket can also cause low vacuum which can effect the brake boost. What is the most likely reason? A bad master cylinder can introduce air into the lines, as can a failure at a caliper or wheel cylinder. Al+ClX2AlClX3. Fluid will not run from the master cylinder while you remove it. Correct answer A-You torque an adjusting nut to a specified torque and back off the nut till it lines up with the hole and install the cotter pin. They will need to be resurfaced. Which is the correct way to service these brakes? d. Repair leak and replace brake linings. If your brake pedal feels squishy, "like stepping on a plum," and won't stop on the way down unless you pump it, or the brake pedal sinks to the floor with little or no resistance, you have a dangerous situation and should NOT drive any further! a. Should I drive my car? I highly recommend having your car towed; this is a very dangerous situation, and the problem needs to be fixed before the car is driven. On a car with single piston floating caliper disc brakes, the disc brake pad between the caliper piston and the rotor is badly worn. The anchor pin never has to take all of the braking force when the brakes are applied, so its strength does not matter. Who is correct? There are different causes for brake drag. c. Both A and B Correct answer B-If the amber light is on it indicates an ABS fault and the system will revert to regular brake operation without ABS. Correct answer D-Both technicians are wrong. Seized wheel cylinder piston A slow descent of the brake pedal means that the pressure is leaking out of the master cylinder. You shouldn't waste your valuable time trying to rebuild it. The brakes on quick take up systems use the same bleeding procedure as those without this valve. Again, you will have to measure the drums to determine if they can be resurfaced or not. a. Spalling c. Pressure differential switch Question: What makes a car's disc brakes drag hard after a 15-minute drive? B. After that, fixing it is often easy with the help of your Haynes manual. The residual valve (often in the master cylinder or proportioning valve) keeps a small amount of pressure in the brake lines so the pedal doesn't have to travel so far until initial engagement; a failure here can be difficult to pinpoint. You should clean or replace the adjusters to eliminate the problem. The other three answers can lead to a low brake pedal. If your rear drums are the cause of the brake pulsation, you will feel the pulsation at this time, and the car will shake when the emergency brake is applied. Technician B believes there is an issue with the lateral runout of the rotor. b. with the engine running b. Manage Settings Some vehicles have __________ openings in the backing plate to allow for manual adjustment of the brake shoes. Answer: I recommend checking the brake light switch, it may be out of adjustment and applying a little pressure to the brake pedal. An automobile has a weight of 2700 lb and is traveling forward at 4 ft/s when it crashes into the wall. Situations such as heavy loads or long downhill grades where the brakes are used heavily can lead to overheating of the lining, drums, or brake fluid, resulting in a loss of braking called: Which brake is used for holding a vehicle in place when its stationary? A properly working booster will make it easier to hold the pedal and may even slightly depress the pedal by itself. Abnormal noise. Note: I dont recommend pulling up on the emergency brake handle at high speeds, it can cause your rear brakes to lock up and send the vehicle into a spin causing death or serious injury! 3 Hydraulics-Related Sources of Brake Drag If your car sits for long periods without moving, moisture from rain or high humidity causes your rotors to rust, except for the patch of rotor surface where the pads rest. "Scratcher" and "sensor" are types of disc brake pad __________ indicators. You can pump the brakes before application to help offset this problem, but you need to get it fixed. This braking problem can be caused by several different things, even the tires (see below), but the most common cause is a frozen caliper. As rotors age, they go through the heating and cooling process thousands of times, so it's inevitable for them to lose their shape or trueness. Any pull caused by unevenly worn tires will be amplified when you step on the brakes. The building pressure in the system results in brake drag and possible brake lockup. b. Technician A is wrong because recalibration is not required for these sensors. Using the screwdriver, gently pry out the rubber grommet that protects this access cover. Technician A says to verify the wheel speed sensor operation and compare all four wheel speed sensor outputs to the data list. b. Correct answer C-Both techs are correct. Five Common Brake Problems in Cars - AxleAddict The system reverts to regular brake operation without ABS. Within disc brake calipers, the pistons are sealed by a: Which of the following take(s) up the clearance as disc brake pads wear? Who is right? 100100100 Who is correct? d. Neither A nor B, The front brake rotors and pads are being replaced on a vehicle equipped with a TCS (traction control system) and electronic stability control system (ESC). There are many possible causes of this shaking, including the front rotors being warped, hot spots (slight irregularities) on your rotors caused by excessive heat, or pad impressions. c. Defective metering valve. c. Excessive brake pedal travel If you were to remove the line at the master cylinder and at the caliper, could you blow compressed air through it? There are only about nine evil mechanics in the world, they just move around a lot! When I apply the brakes, especially downhill, I feel the brake pedal presses itself more than I do. Thus, there are many ways to design a lens that has a particular focal length in air. 1. Who is correct? If there is a leak somewhere the fluid level may be so low as to make even the redundantsystem ineffective. What are possible causes? A short power assist brake booster push rod will lead to which of these? 200MeV200 \mathrm{MeV}200MeV is typical energy released in a fission reaction. The way to prevent these issues is to avoid driving in deep puddles, or areas where salt is used on the roads, but if that isn't an option, be sure to clean the wheels and underside of the car often in winter. A only B only It will need replacement or resurfacing. I recommend having all the brake lines, calipers, and the master cylinder checked for leaks. This delay causes the spongy feel. Technician B Technician B says a defective wheel displays looseness or excessive play in the steering wheel especially while driving over rough road surfaces. You will find the booster between the master cylinder and the firewall in your engine compartment. It's also possible to check the blink codes with the DLC. The brakes of large trucks are different. d. A faulty power booster. Search by Part Number(s), Keywords, or VIN, Chevy Brake Problems: Common Issues and How to Fix Them, How to Program Chevy Silverado Key Fob Remote, How to Reset Your Chevy or GMC Oil Change Light, How to Unlock Your Chevy or GMC Radio for Free, How to Update Chevy and GMC Navigation Units. If it involves only one of the front brake units, the vehicle will pull to the side with the dragging unit. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page.. \mathrm{m} / \mathrm{s}.pB,i=4,6,0kg.m/s. As in: hit the brakes, let go, brake pedal comes back up, master cylinder side piston doesnt came all the way back and keeps pressure on the master. a. B only d. Steering gear problem. If your whole car shakes when your brakes are applied, it could be just your rear brakes. To reduce this, the mating surfaces need to be cleaned and lubricated. If your brakes squeak and you want to know why, maybe I can help! A car that pulls to one side can be annoying and also dangerous. Another cause of a hard brake pedal can be a brake caliper that is stuck or seized. Excessive Push Rod Length The brake system in your car contains numerous components, each of which plays a distinct role in braking. Frozen caliper piston Who is right? Who is right? A) Warped rotors B) anti-lock braking system operation C) Both A and B D) None of the above Both A and B Which of the following can cause brake system dragging? The star adjuster should be adjusted one full turn to back the shoes away from the drum. c. Both A and B Brake fade is loss of stopping power that occurs when excessive heat reduces friction between brake shoe linings and drum. A only b. Seldom does this result in a car that won't move at all, but driving with the brakes dragging is unsafe and will result in even more damage in a short amount of time if not repaired. Brake Proportioning Valve Problems - In The Garage with CarParts.com It will not be caused by lateral runout, which would cause brake chattering or pulsing. All of these would cause a low brake pedal, EXCEPT: They will need to be resurfaced. b. Proportioning valve brakes midterm Flashcards - Cram.com I put new calipers, rotors and rubber lines on a couple of months ago and now the calipers stick sometimes. I recommend having this area of the brakes inspected first. How To Determine Cause of Brake Drag. This is a very common brake issue on all makes and models: when youre driving at highway speeds and you apply your brakes, the steering wheel shakes. When I bled the lines, the driver side brake fluid wouldn't come down. Correct answer B-Having a seized caliper piston leads to a high pedal. Brake fluid expands as brake fluid temperature rises from normal braking. If the brake fluid reservoir is full and there are no signs of leaks, the problem is usually an internal problem that you cant identify just by looking at the master cylinder. Technician B says the test involves checking the level of vacuum supplied by the engine or vacuum pump. measure the pad-to-caliper piston clearance. Meanwhile, pull up on the handle just enough to feel the rear brakes grab slightly. Find out what these noises mean and what might fix them. Braking: Car Pulls to One Side - Tomorrows Technician Correct answer B-Having a seized caliper piston leads to a high pedal. Answer: Most likely your caliper is defective, if it were the master it would most likely be more then one brake caliper sticking. Checking your brakes at regular intervals is a goodpractice towards the maintenance of your Chevy. Connect a hose to the caliper bleeder screw and insert the other end of the hose into a suitable container, open the bleeder screw, then use a C-clamp or pliers to slowly bottom the piston in the caliper Technician A says that all 3 channel ABS systems use only 3 wheel speed sensors. Although, if you have a fluid level sensor in the master cylinder reservoir, you may see this light come on when the fluids are low. The correct answer is C. Of the choices given, only an out-of-round brake drum can cause pulsation in a hydraulic brake system. a. You'll need to remove the caliper and inspect all moving parts to diagnose the problem. Answer: Is your abs light on? d. Repacking a front wheel bearing, Technician A says a defective wheel or axle bearing can make a growling or rumbling noise. Fluid pressure can bypass the twist during the application, but not return to the master cylinder after release. eCFR :: 49 CFR Part 396 -- Inspection, Repair, and Maintenance Another cause of a hard brake pedal can be a brake caliper that is stuck or seized. Basic Body Work: Fixing a Deep Scratch in Your Car's Paint. A soft brake pedal is a MAJOR brake issue. These records must include: (1) An identification of the vehicle including company number, if so marked, make, serial number, year, and tire size. A. That's why the power assist begins to function properly after the engine runs. What could be the cause of the problem? Brake Noises: What Causes Them and How to Fix Them. d. Metering valve. A vehicle with 4-wheel disc brakes has a brake squeal. The four noises that car owners complain about most often: CV joint noise, water pump noise, belt noise, and heat shield noise. Which technician is most likely correct? This difference in pressure happens when the line is pinched or kinked and leaves the brake unit applied and dragging. a. B. Who is right? As a result, the car may exhibit a dragging sensation, since the brakes at the affected wheel are applied (or partially applied) at all times. The star adjuster should be adjusted until there is a slight drag on the drum. Another possibility is that the pistons got bent, during a brake job or a car accident, and can't move freely anymore, causing the caliper to bind and limiting the amount of pressure to the pads. If the slide pins are your problem, they need to be cleaned and lubricated or replaced. Slight scoring or heat spots The master cylinder seems to be okay. b. Brake Squeal:A vibration between the pads and the calipers or the pads and the rotors can cause them to squeal. How To Determine Cause of Brake Drag - Ford Truck Enthusiasts Forums If you have rear disc brakes, this procedure may not work because some makes and models have a separate emergency brake, which is connected not to the rear rotor and caliper, but to a special drum inside the rear rotors with a separate braking system. Other times it is fine. It can also be due to a corroded or jammed caliper piston or a caliper that has corroded bushings or mounting pins. Technician B is wrong because backing off the castle nut will not cause the bearing to overheat. Consider a system consisting of both objects A and B. Excessive Brake Travel: If the brake linings are worn, the drum brakes are misadjusted or the brake lines have air in them, you will have this issue. a. ABS Diagnostic Trouble Code set Technician A says that when reassembling a duo-servo brake, the backing plate pads should be lubricated. Object B has initial momentum pB,i=4,6,0kg.m/s.\vec{p}_{B, i}=\langle 4,6,0\rangle kg. B only The ABS warning light usually comes on when there is this type of problem. See less 79 RC bought from original owner in 2006 Then there are minor issues such as brake squealing, brake shudder/pulsing, burning smells, leaking fluids, pulling to one side, etc. Brake rotors need to be refinished under all of these conditions EXCEPT: The anchor pin never has to take all of the braking force when the brakes are applied, so its strength does not matter. A only Technician A says excessive brake pedal freeplay could be the cause. You could add shims, use a brake noise aerosol, or brake grease to the backs of the pads to dampen the noise. The PCV valve vents the crankcase of blow by gases and isn't part of the braking system. a. Al+ClX2AlClX3\ce{Al + Cl2 -> AlCl3} A only D. Noticeable brake pulsation. "Scratcher" and "sensor" are types of disc brake pad __________ indicators. One way to test your rear drum brakes is to apply the parking brake slightly while driving, because the parking brake uses the drum brakes in the rear. The brakes on your car are probably the most important system, and due to the difficult job they do and how often they are used, they are also one of the most likely to wear and need service. B. c. Both A and B This article is accurate and true to the best of the authors knowledge. Even with proper maintenance, you may find yourself with an unexpected brake problem -- here are some of the most common examples. In the following questions, "initial" refers to values before the collisions, and "final" refers to values after the collision. b. Arcing Turn the star-shaped adjuster a few times. An intermittent noise when braking lightly, as in the video below, could also be related to an uneven surface on the rotors. You could try having a fine cut done to the brake shoe surface of the drums and lightly sand them after the cut, or replace the drums. An often-misdiagnosed cause of pull is a collapsed brake hose. If it is, you should be able see the fluid on the carpet under your dash, just over your brake pedal. In this article, I will explain the most common reason for a slipping automatic transmission and the most common reason for a slipping standard transmission. Then, it should be backed off until there's a drag on the wheel. Correct answer D-The metering valve controls the pressure to the front disc brakes on a combination system and if defective can allow too much pressure causing a lock-up. On ABS systems that have a high-pressure accumulator, this is depressurized by: In the brake booster there is a washer that is suppose to keep the pushrod centered as it goes into the mastercylinder. c. Seized caliper piston on the other side Most instances of a hard pedal come down to a failure in the power boost system, whether vacuum based or hydro-boost (used mostly on diesels, we won't be covering it here). 2. After a master cylinders replaced and the brake system is bled what must happen? On a car with a drum/disc system, the front brakes lock up on light pedal application. B. Who is correct? Which of the following would NOT cause a disc break to drag? That way, if there is a leak in one part of the system, it should only affect one front brake and one rear brake. Correct answer D-A restricted disc brake caliper hose won't cause pedal pulsation. D. 400400400. Auto Test -sambooy Flashcards | Quizlet We and our partners use cookies to Store and/or access information on a device. If you work by process of elimination, starting with the most likely cause and working through to more complex issues, you can easily diagnose the problem yourself. Check and make sure there is free play at the top of the brake pedal after driving and braking for a while, if there is no free play, something is out of adjustment. Who is right? Technician B Questions are welcome. Question: Does an emergency brake in a car not work after an accident? Technician B says the cause could be a stuck closed residual check valve in the hose from the intake manifold to the power brake booster.