Who is right? If you have a soft or sinking brake pedal and are looking for information on what's causing it or what you should do next, you'll find the answers here. The other situations wouldn't be caused by the lack of free play. d. Neither A nor B. You can buy an overhaul kit for calipers, but they are hard to find and your caliper may not be worth bringing back to life. You could add shims, use a brake noise aerosol, or brake grease to the backs of the pads to dampen the noise. Technician A is wrong because recalibration is not required for these sensors. A low brake pedal can also be due to a fluid leak or worn brake linings. Master Cylinder: An incorrect brake pedal adjustment can cause brake drag. In case these terms are new to you, real quick, I'll tell you that to stop the car, the master cylinder sends out fluid through tubes under pressure to drive a pincher (a caliper) that presses a pad or shoe against a metal disc (rotor) or drum. The effectiveness of braking is mostly determined by: Tech A says that the heavier the vehicle, the more stopping power is needed. Correct answer B-Disc brake squeal is often caused by movement of the disc brake pad during braking. 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. The mechanic is now telling me I need all of those parts replace again. This pedal adjustment is crucial, and if adjusted too tightly, the vent port of the master cylinder can become blocked. Technician A is working on a vehicle that was brought in with excessive brake pedal travel. This article is accurate and true to the best of the authors knowledge. The other brake pad is slightly worn. Technician B says that the star wheel assembly should be lubricated on the floating end. Scraping Brakes:Metal-to-metal sounds mean that the pads or shoes are worn out. If you get no assist, you need a new check valve. Check out the system to make sure that you do not have a caliper leak or an oil leak. This delay causes the spongy feel. This can be repaired by resurfacing or shims. Answer: The first thing you need to do is remove all four wheels and inspect all caliper slide pins, pistons, and brake pads and shoes. The brake pedal is firm when applied. B. Who is correct? Correct answer B-This is the standard process by many OEMS when a new rotor is installed. If the coefficient of kinetic friction between the wheels and the pavement is k = 0.3, calculate the impulsive force on the wall if the brakes were applied during the crash.The brakes are applied to all four wheels so that all the wheels slip. Any brake booster (whether from Master Power or any other supplier) needs a vacuum source to operate. It's possible your ABS module is no good. These records must include: (1) An identification of the vehicle including company number, if so marked, make, serial number, year, and tire size. Brakes that Drag: Dragging brakes cause the brakes to wear out faster, and they can cause steering pull and tire wear. A rotor face must be within .0005 inch of being parallel and flat with no more than .003 inch of runout. C. Both technicians Technician A is wrong because the proportioning valve only affects brake lockup and is not used on 4-wheel disc brakes only on disc/drum combinations. Technician B believes there is an issue with the lateral runout of the rotor. I replaced master cylinder already. A only A brake hose problem like this can take two forms. A. The ABS (antilock brake system) amber light does not go off after the engine is started. We and our partners use cookies to Store and/or access information on a device. Correct answer B-Disc brake squeal is caused by the brake pad moving while braking. d. Brake light is illuminated. Brake pad friction materials may be manufactured from any of the following EXCEPT: makes a noise if the brake pads are due to be replaced. If the piston is stuck, and the fluid pressure can't push it back into the bore easily, the pressure on the pads will be uneven and the car will pull. The brakes on quick take up systems use the same bleeding procedure as those without this valve. 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. d. Neither A nor B, A wheel speed sensor is being diagnosed using the OEM (original equipment manufacturer) diagnostic scan tool. Glazing is more a problem with drum brake systems than disc systems because pads get more ventilation. The ABS warning light usually comes on when there is this type of problem. 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? When the fluid gets warm and expands, there is no where to go, so it starts applying the calipers, and the brakes drag. For more information about ASE, visit the official ASE website at www.ase.com, Copyright 2008-2023 All Rights Reserved Privacy Policy Disclaimer Sitemap. I put new calipers, rotors and rubber lines on a couple of months ago and now the calipers stick sometimes. Technician B d. Steering gear problem. D. Neither technician. Technician A believes it's a defective proportioning valve issue. Technician B says a defective wheel displays looseness or excessive play in the steering wheel especially while driving over rough road surfaces. Contact. 100100100 c. VAV_\text{A}VA and ITI_\text{T}IT? Then there are minor issues such as brake squealing, brake shudder/pulsing, burning smells, leaking fluids, pulling to one side, etc. You should clean or replace the adjusters to eliminate the problem. To further reduce the noise, do not machine the rotor more than needed. a. Technician A says the cause could be a leaking power brake booster diaphragm. D. Neither technician. Technician A is wrong because the parking brake only affects the RED Brake Light not the amber. The brakes are being bled on an older vehicle equipped with a quick take up valve in the master cylinder. Correct answer C-The weak hydraulic brake hose causes a spongy pedal. Who is correct? c. Both A and B C. Both Technicians a. Brake fluid expands as brake fluid temperature rises from normal braking. B. What is the most likely reason? Rotors should be refinished when there is scoring, heat spots, lateral runout, pedal pulsations or thickness variation. A vehicle has a very erratic brake pulling concern while applying the brakes. Technician B To fix this problem you will need to replace the caliper. Question: I have a 99 Honda Civic EX. b. d. Repair leak and replace brake linings. This can be due to oil, grease or fluid on a pad, a caliper that is stuck, brake line blockage, or wheel bearings that are loose. Opening or loosening any part of the hydraulic system is dangerous because of the fluid pressure. They will need to be resurfaced. When you remove the master cylinder, you must take all these steps EXCEPT: Correct answer D-Draining the master cylinder isn't required. Technician A says that when reassembling a duo-servo brake, the backing plate pads should be lubricated. Answer A, zero brake pedal free travel, will cause a dragging brake condition, but not pulsation. This leads to the brakes dragging. Buying a new caliper may cost more but you will make up the cost with the time you save. Air in the hydraulic system If this is what is going on, you need to identify and replace the faulty part. 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. Always use OEM recommended clips and anti-squeal shims. Hard Pedal- It takes much more pressure to get the same amount of pedal travel and braking force. Who is right? C. Both technicians 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. If the master cylinder is leaking externally, you will see fluid dripping from the place where the rod goes into the cylinder. B only a. Within disc brake calipers, the pistons are sealed by a: Which of the following take(s) up the clearance as disc brake pads wear? 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. Glazed brake pads result from excessive heat. Why are X-rays, gamma rays, and fast-moving electrically charged particles potentially harmful to our bodies? B. C. Brake adjustment Technician B believes that the brakes can't be bled. 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? Again, you will have to measure the drums to determine if they can be resurfaced or not. a. 2023 The Arena Media Brands, LLC and respective content providers on this website. a. C. Both technicians The drum brake adjuster is located under an access cover in the back of the drum brake. . a. Answer B, glazed . You can resurface the rotors if they are still thick enough. When you make the final adjustments to the drum brakes: It can also be due to a corroded or jammed caliper piston or a caliper that has corroded bushings or mounting pins. A. Technician A says the quick take up valve must be depressed. d. while driving the vehicle slowly. The dragging sound could be caused by the brake drum not fully releasing when the brake is released. You may also need to have the drum or the rotors replaced or resurfaced because you waited too long to change the shoes and pads. b. A car that pulls to one side can be annoying and also dangerous. B. Al+ClX2AlClX3. Most braking systems work on a diagonal braking design for safety reasons; that is, the left front and right rear brakes work together and so do the right front and left rear. This lubrication will help prevent a possible squeaky noise as the shoes move across the plate. Technician B Air and vaporized fluid are compressible and, if allowed into a hydraulic brake system, the brake pedal will feel spongy and the force transmitted to the lining will be reduced. ASE identifies suspension both . 3 Basic Kinds of Valves in a Non-ABS System. B. B. 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! After a master cylinders replaced and the brake system is bled what must happen? Using the screwdriver, gently pry out the rubber grommet that protects this access cover. Question: The brakes on my 2010 Lexus ES brakes kick back when turning the steering wheel. That bleeds out any vacuum. Who is right? Some of our partners may process your data as a part of their legitimate business interest without asking for consent. Tech B Tech A says that the vacuum booster increases the vacuum in the brake system. On a bearing that has been shock loaded, the race (cup) of the bearing can be dented. Correct answer A-You must adjust the star adjuster until there's a slight drag on the drum. This also reduces braking power. 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. Bad front tires, or broken belts in a front tire, could cause it. Object B has initial momentum pB,i=4,6,0kg.m/s.\vec{p}_{B, i}=\langle 4,6,0\rangle kg. Worn drums may also cause shuddering or pulsating that will become noticeable once you step on the pedal. You shouldn't waste your valuable time trying to rebuild it. A) Internal master cylinder leak B) Warped rotors C) Both A and B D) None of the above None of the above Correct answer C-Both techs are correct. Sometimes, though not very often, the brakes won't work, and it sounds like it's grinding for one or two seconds. Brake drag often occurs when the fluid in your system overheats. A master cylinder may fail in two ways: internally or externally. Are they safe? If you have this type of rear braking system, it is almost impossible to isolate the rear brakes. On ABS vehicles, the ABS pump or the high-pressure accumulator can be the cause of power loss. A worn or corroded master cylinder bore causes excess pedal effort resulting in dragging brakes.if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[336,280],'freeasestudyguides_com-medrectangle-4','ezslot_3',116,'0','0'])};__ez_fad_position('div-gpt-ad-freeasestudyguides_com-medrectangle-4-0'); Brake Lines and Hoses: There may be pressure trapped in the brake line or hose after the pedal has been released. In the brake booster there is a washer that is suppose to keep the pushrod centered as it goes into the mastercylinder. a. Spalling The vehicle pulls to the side under heavy braking D. loosening the front wheel bleeder screws with the ignition switch on. The enzyme phosphoglucomutase interconverts glucose-111-phosphate and glucose-666-phosphate. One way a caliper can freeze up is by the piston on the caliper being stuck in its bore. 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.. Every rotor has a "minimum spec" for thickness, usually stamped on the rotor near the hub where the lug nuts are. I changed the brake pads, but that didn't help much. d. Metering valve. Technician B says the new rotors should be indexed to the hub using a dial indicator for the least amount of runout. A hydraulic system uses the incompressible nature of fluid to transfer force from your brake pedal all the way to your brake caliper, causing it to close around the rotor and slow the momentum of your wheel. The correct answer is C. Of the choices given, only an out-of-round brake drum can cause pulsation in a hydraulic brake system. Questions are welcome. Brakes on an older vehicle with a quick take up valve in the master cylinder are being bled. You can do this test if your emergency brake handle is near the center console and it is the style that you pull up with your hand. The first step when diagnosing a problem with caliper mountings, slides, and pins is to: The purpose of the lugs on the backing plate is to: On some pads, the depth of the groove is set so: Disc brake pads consist of friction material ________ or _________ onto a steel backing plate (disc brakes). This pedal adjustment is crucial, and if adjusted too tightly, the vent port of the master cylinder can become blocked. D. Neither Technician. Technician A is wrong because excessive rotor runout will cause brake pulsations with no effect on wear. Technician A is wrong because the parking brake would only affect the red brake light. Here is the list of possible causes: Service and parking brake adjustment Rear brake hardware Shoe lands or bosses GM clip in wheel cylinders Brake drum condition Brake shoe contamination Brake valving Friction material Low Brake Fluid:Your Chevymay develop a leak in the system that will result in the fluid level going down. Next, hold your foot to the pedal while starting the engine. It's worth grabbing a flashlight and looking to see whether the master cylinder is leaking visibly. Glazed shoes or pads cause brake fade resulting in a loss of friction and reduced braking performance. Meanwhile, pull up on the handle just enough to feel the rear brakes grab slightly. The same factors can cause cable operated parking brakes to jam up as well, requiring a replacement of the parking brake cable. Who is right? An intermittent noise when braking lightly, as in the video below, could also be related to an uneven surface on the rotors. What's more, I'll teach you to fix it in either case. To determine if your rear brakes are the problem, you need to test them in isolation. The other choices do not affect this concern. Failure of lateral runout or thickness variation checks Is this a caliper or could it be a blockage in the brake hose? Lubricate slide pins on disc brakes to prevent brake drag and binding. Answer: It all depends on where you got hit, where the emergency brake is located and if you have electronic emergency brakes. To reduce disc brake squeal, all mating surfaces of the brake should be clean and lubricated. What is the cause? The ABS light doesn't go off after the engine starts. I replaced the brake pads again, both calipers and rotors. All of these would cause a low brake pedal, EXCEPT: Slight scoring or heat spots After that, fixing it is often easy with the help of your Haynes manual. \mathrm{m} / \mathrm{s}.pB,i=4,6,0kg.m/s. Technician B 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. Other times it is fine. Poor stopping Correct answer C-New brake rotors don't need to be refinished. d. Air in the hydraulic system. Regardless, I recommend having a thorough brake inspection by an experienced mechanic. Answer: No, you should really look for a new mechanic, pads maybe if you drive a ton of miles in stop and go traffic or you're a mail carrier, lines are rarely replaced. Why is this enzyme likely to include a side chain such as Ser in its active site? If the drum is machined beyond its limit, the contact surface moves further from the shoes. c. Low brake fluid A only Unusual brake pedal feel. Which of the following could cause a pulsating brake pedal on a truck with hydraulic brakes? Who is correct? Some vehicles have __________ openings in the backing plate to allow for manual adjustment of the brake shoes. Fear of the unknown causes anxiety. Sinking Pedal: You may notice this while sitting at a stop light. It sounds to me like some components aren't moving freely and are getting stuck causing the pulling and noises. The lack of brake pedal free play on a vehicle might cause: Correct answer C-when there's no free play, the brakes can't disengage fully. If every time you apply your brakes, your brake pedal pulses up and down, the problem is usually caused by the rotors being warped or out of true. b. To get a sense of the scale of the energy, if we were to use this energy to create electron-positron pairs, approximately how many pairs could we create? Sketch each of your designs. Assume the brakes are not applied. DOT 5 Tech A says that quick take-up master cylinders use two additional pistons to move brake fluid faster. measure the pad-to-caliper piston clearance. Why is there a rear knocking noise from the drums when applying the brakes? 1. Correct answer A-the biggest downside of drum brakes is their susceptibility to fading. This difference in pressure happens when the line is pinched or kinked and leaves the brake unit applied and dragging. Question: My Chevrolet 2006 has some braking problems. A slight gap should be present between the pushrod and the master cylinder. The anchor pin never has to take all of the braking force when the brakes are applied, so its strength does not matter. Replace the brake linings Even today, your brakes can fail completely, but there are failsafes built into the system to prevent that from happening in most cases. 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. Which of the following can cause brake pedal pulsation? The caliper can also freeze up if the caliper slide pins have lost lubrication because they have not been maintained properly. Which technician is most likely correct? Which of the following can cause brake system dragging? D. Neither technician. The lens-maker's equation has three design parameters. a. The brakes can fail if your hydraulic system or master cylinder is leaking. Additionally, brake dragging can also be caused by frozen emergency brake cables as well as . Technician B believes it's caused by movement of the brake pad while breaking. Answer: You have a rear knocking noise from the drums because your shoes are being pulled away from the backing plate and snapped back into place by the spring clips. A better idea of where the master cylinder is located in relation to the brake pedal. Who is correct? The first thing you should do is check your brake fluidlook in your owner's manual to see how. a. c. Pressure differential switch If nothing happens, check the vacuum connections, and if they are okay, you need a new booster and vacuum hose. Technician B says the cause is a faulty residual pressure check valve admitting air. Which of the following is the proper procedure? This also reduces braking power. D. Low brake fluid. You also want to use OEM clips and anti-squeal shims. Mechanical fading is when the drum gets too hot and expands away from the linings. Technician B says when this happens the brakes will operate like a normal non-ABS brake system. The two main types of disc brake calipers are: The disc brake caliper is attached to the, Sliding calipers have pistons that are positioned on, bleed air or vacuum from the power booster, Brake bleeder screws enable all of the following tasks to be performed EXCEPT. A. 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. They can also cause you to use . The wheel cylinder is attached to the ________. Brake pads are being replaced on a vehicle with four-wheel disc brakes. It can also be due to a corroded or jammed caliper piston or a caliper that has corroded bushings or mounting pins. Technician A At the first sign of trouble with your brakes, you need to either fix them or seek help from a certified GM mechanic. Answer: Yes, brake pads can cause problems for brakes on a car. The failing bearing allows the hub to move around, effectively pushing the brake pads back into the caliper as far as it can. It doesn't have power assist until the engine runs for a minute, then it begins to work normally. The four noises that car owners complain about most often: CV joint noise, water pump noise, belt noise, and heat shield noise. This site is owned/ operated by an authorized GM Genuine Parts/ACDelco Seller. B. The rear brake linings are soaked with axle grease but still have a lot of lining left on them. Who is correct? If there is plenty of fluid in evidence, check if it is hot; repeated hard use, towing, descending a steep hill, or a dragging calipercan boil the fluid. A. If it involves only one of the front brake units, the vehicle will pull to the side with the dragging unit. 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. Who is correct? Answer: The brake fluid temperature rising and pressure building in the brake system. A only This patch of uneven rotor surface is called a pad impression and will cause the brakes to pulsate. DOT 3 brake fluid should not boil until it gets above 400 degrees Fahrenheit, but old brake fluid that has absorbed water can boil at as little as 284 degrees, which is why it needs to be changed every other year. There are four types of brake fade. Correct answer D-The leak must be repaired before the linings are replaced. HubPages is a registered trademark of The Arena Platform, Inc. Other product and company names shown may be trademarks of their respective owners. Pulsation results from something loose in the system or by an unparallel rotor. The component in the Figure is involved what procedure? The PCV valve vents the crankcase of blow by gases and isn't part of the braking system. Technician A says a parking brake not fully released could be the cause. b. Luckily, changing a brake caliper is not a hard job, and can be accomplished in about an hour. When I bled the lines, the driver side brake fluid wouldn't come down. Brake Noises: What Causes Them and How to Fix Them. If a 40 kg person is accelerating at 10m/s^2, then the magnitude of the force acting on him or her is 400 N. Write a C++ statement that prints the message The number is not valid. if the Brake fade is when the brake fluid is contaminated, so it causes a soft brake pedal, air in the lines, leaking master cylinder, frozen or seized caliper pins or piston, worn out pads, and glazed rotors. Check out the system to make sure that you do not have a caliper leak or an oil leak. A properly working booster will make it easier to hold the pedal and may even slightly depress the pedal by itself. The building pressure in the system results in brake drag and possible brake lockup. This brake pulsation can be fixed very easily by having your rotors resurfaced (which is cheaper) or replaced (more expensive). What's up with that? Question: My brakes squeak only when I back up. A only A only I recommend having all the brake lines, calipers, and the master cylinder checked for leaks. That way, if there is a leak in one part of the system, it should only affect one front brake and one rear brake. Question: My rear inner pads wear down faster than the outer ones. c. Excessive brake pedal travel Now I have loud grinding sounds coming from the front left tire. A spongy brake pedal may be caused by: If you do a lot of highway driving and you happen to be hard on your brakes, you will probably run into this problem many times in the life of your car. The vacuum booster can be checked by pumping the pedal a few times while the engine is off. How To Determine Cause of Brake Drag. With the brakes applied on a vehicle with power brakes, the pedal moves down slightly when the engine is started. d. Repacking a front wheel bearing, Technician A says a defective wheel or axle bearing can make a growling or rumbling noise. d. Fluting. 505050 A only Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters. An example of data being processed may be a unique identifier stored in a cookie. Figuring out the problem and solutionis simply the result of having the right knowledge combined with an intelligent, systematic approach.