**Common Issues with Brake Pedals**

The brake pedal is one of the most critical components of a vehicle's braking system, and any issues with it can lead to serious safety concerns. In this article, we'll explore five common reasons why your brake pedal may be sinking or not responding properly, along with some tips on how to diagnose and potentially fix these problems.

**Worn Tires**

One of the easiest things to check when it comes to brake pedals is the condition of your tires. Worn-out tires can cause a significant amount of play in the brake system, leading to a sinking or spongy brake pedal. To check your tire wear, simply pull off the wheel and take a look at the tread depth. If your tires are worn down to 1/8 inch or less, it's time to replace them.

**Fluid Leaks**

Another common issue that can cause a brake pedal to sink is fluid leaks in the braking system. When you check the brake fluid level, if you see fluids leaking out of the ABS module or any other component, it's a good idea to replace the faulty part as soon as possible. This is because brake fluid leaks can lead to serious safety issues, including loss of control while driving.

**ABS Brake Failure**

The Anti-Lock Braking System (ABS) is a critical safety feature that prevents wheels from locking up during hard braking. When the ABS fails, it can cause the brake pedal to sink or not respond properly. This is often due to a problem with the actuator module, which is responsible for controlling the ABS system. If you notice your ABS light coming on and the brake pedal sinking, it's essential to have it scanned by a professional mechanic as soon as possible.

**Faulty Brake Master Cylinder**

The brake master cylinder is a critical component of the braking system that converts non-hydraulic pressure from the brake pedal into hydraulic pressure that applies the brakes. When the brake master cylinder fails, it can cause the brake pedal to sink or not respond properly. This is often due to a fault in the valve body or piston seals, which can cause leaks and lead to low brake fluid levels.

**Rarity of Computer Failure**

In some cases, a sinking brake pedal may be caused by a failure in the vehicle's computer system. Specifically, the Power Control Module (PCM) or Anti-Lock Braking System (ABS) computer can fail due to wear and tear or other issues. This is relatively rare, especially on newer vehicles, but it's essential to keep an eye out for any signs of computer trouble, including no injector pulse or failure to pump power.

**Diagnosing the Problem**

If you suspect that your brake pedal is sinking due to a specific issue, there are several steps you can take to diagnose the problem. First, check the tire wear and condition, as this can often be the culprit. Next, inspect the brake fluid level and look for any signs of leaks or fluid contamination. If the ABS light is coming on, it's essential to have it scanned by a professional mechanic to determine the cause of the failure.

**Prevention**

While diagnosing and fixing common issues with brake pedals can be a challenge, there are several steps you can take to prevent problems from occurring in the first place. Regularly checking tire wear and condition is essential, as is keeping an eye on your brake fluid level. Additionally, having your ABS system regularly serviced and inspected by a professional mechanic can help identify any potential issues before they become major problems.

**Bonus Questions and Answers**

In this section, we'll answer some common questions from viewers about brake pedal issues.

**Q: What's the most expensive part to replace?**

A: The Anti-Lock Braking System (ABS) actuator module is often one of the most expensive parts to replace, especially on newer vehicles. This is because it's a complex component that requires specialized tools and expertise to repair or replace.

**Q: How do I prevent brake pedal problems?**

A: Regularly checking tire wear and condition, keeping an eye on your brake fluid level, and having your ABS system regularly serviced and inspected by a professional mechanic can help identify any potential issues before they become major problems.

"WEBVTTKind: captionsLanguage: enrev up your engines today I'm gonna showyou five reasons that your brake pedalcan sink when you step on now a sinkingbrake pedal is a scary thing you step onyour brakes and a pedal start sinkingit's a very common problem and there'sfive separate reasons for it I'm gonnaexplain them all right now, now the firstreason that your brake pelicans thinkit's cuz you have an external leak it'sleaking fluid that you'll be able to seesomewhere some of your cars low likemine you Jack it up in the air hey yougot a truck or tall SUV you can justcrawl under there without jacking it upbut this is love so we got a Jack it upthink of a nice strong flashlight so youcan see it even blanked out the camerabut you want a strong one so you don'tmiss anything though with yourflashlight huh look inside at the wheelsyou can see there it's all bone-dry samething now where the brakes are it's allbone-dry there's no fluid leaking downand of course do the same thing for theback brake check inside there too now ifyou really want to do a good job youpull all the wheels off of course andinspect them closely with the flashlightto see if they're starting to leak orthere's any fluid leaking you look atthe brakes themselves and especially therubber hoses that feed them if you havean old car those rubber hoses can leaktoo brake calipersleaking you can buy remanufactured onesgot an old car like this with drumbrakes on the back the wheel cylinders aleak and it'll be leaking inside thereyou replace the wheel cylinders and likeI said the hoses themselves can beleaking these are all external linksthat you'll be able to see you see wetfluid and then you put your finger onit's all slimy like brake fluid you knowyou got to fix that leak first andthat's what's making it sink cuz youlosing pressure now the next thing tocheck for is a brake fluid leak that'snot external but internal the system isleaking and you're losing fluid to checkthe brake master cylinder here to findit's getting low on fluid sometimes thebrake light will come on but try as youmay you can't see any leaks where youlosing fluid you can't see any leaks then themaster cylinder would be leaking some say scotty if it's leaking how come I can'tsee it well that's because the mastercylinder boltsto the brake booster and if it leaks itcan leak on the back seal of the mastercylinder and then the fluid will dripinside the booster which is a sealedunit now on this matrix you can easily seeit there's a master cylinder it bolts tothe brake booster which is this biground black thing it will leak insidehere this is a sealed unit you won't seethe fluid the only way you can see thefluid is when you pull the mastercylinder off and bolt out you'll seethat the brake booster here will havefluid inside it there's not supposed tobe anything inside the brake boosterexcept air you start your car you getvacuum pressure the vacuum hose goes to the booster and it gives you boost andit's all just a bunch of air and whenit's sucked out that gives the extrapressure to boost your brakes stops yourpedals sinking and you're losing brakefluid but you can't see leak anywherepull off the brake master odds areyou'll find the back of the brake masteris all leaking and the booster has fluidin it now since the booster is only madeto have suction the rubber diaphragm canbe ruined if it's full of brake fluid soif it recently happened you take off thebrake master and you see it's leakinginside get any kind of suction devicesuck all that blew it out of there youcan spray some spray brake cleaner inthere and then suck all that out and puta new master on now some guys that areworried especially on an older car if itdid leak in there that will place boththe master and the booster together as aunit so they don't have to worry aboutit being somewhat rotten and the boosterand later it goes up that's a safer wayto fix that now the next way your brakepedal can sink is internal leaks that don'tleak out they don't leak out anywhere andyou might think how can you have a leakif it doesn't leak anywhere well thebrake master cylinder is kind of likeyour heart pumps fluid out when you stopon the brake pedal to the wheels but ifit gets an internal leak so when youstep on it instead of the fluid goingfrom the master cylinder to the wheelsit just leaks inside itself and it's notleaking out anywhere but the pressureinstead of going to the wheels justeither stays inside the master cylinderor goes back into the reservoir and thatreservoir hey when the master cylinderreservoir has fluid being pumped in itit's not gonna leak out anywhere cuzthat's sealed too so it'll just go upand down when you stop on if you don'thave any external weeks but yourlosing pressure you see the master cylinder isn't losing fluid it doesn't get thewhole point that means odds are yourmaster cylinder itself is bad andleaking inside itself and there's a goodway to test it you're not losing anyfluid but with the car turned off youstep on the brake pedal and it sinks allthe way to the floor that tells youyou're losing pressure but since youdon't see any leaks anywhere odds areit's the master cylinder that's leakingitself you don't start the car you justdo it with the car turned off becausesometimes it's the car running when youstep on the brake and it sinks all theway down that's the sign of a badbooster you check that a different waywith a bad booster when you step on thebrake with the car turned off it mightbe rock hard but then when you start thecar and then step on the brake pedal andit sinks all the way to the floor thatshows that the booster has a problemthen it's sinking to the floor with thebooster and in that case if it was hardwith the engine turned off but softturned on you got a bad booster now thefourth thing that can make your brakepedal sink are loose parts on your brakesystem I've seen it where guys worked ontheir car and they didn't tighten upeither the hub when they were changingwheel bearings or you didn't get thecaliper bolts on that hold the brakecaliper on right and it gets loose thenyou're gonna have loose parts and thepedal will sink and if you have a carwith drum brakes like this matrix thathas disc in the front but drums in theback if the drums are worn or the brakeshoes are worn and not adjust the tightit'll sink because there's too much playwhen you stop on the brakes instead ofgoing a little bit they have to go a lotand I mix the brake pedal thing so youcheck to make sure they're adjustedright and that they won't just all wornout and worn tires hey that's theeasiest thing to check you just pull offwheels and see if things are worn outand if I were not you replace it it getshard you know while that pot was tooworn it was causing too much play that'sthe absolute easiest thing to checkaside from just purely three pull up thewheel you see the fluids leaking allover the place you know you need to fixthat leak now the fifth and last thinggetting cause brake pedals to sink it'sprobably the most expensive and hardestone to figure out when you go under thehood and go over hereyou see all this crazy-looking stuffwell that's the main actuator for theanti-lock brake system and a problem inyour anti-lock brake system can alsocause the pedal to sinkthat can get expensive it's all computerrun when you slam on your brakesanti-lock brakes does exactly what itsays it keeps your brakes from lockingup so if the sensors on one wheelshoulder it's slipping and the other oneisn't then it's got a actuate valve sothat they all stop evenly so the cardoesn't pull and slide all over theplace well it's all fine and dandy whenit actually works when they break thevalves inside that modulator can go badand they can stay open when they'resupposed to be open which makes thepedal go to the floor things up they'resupposed to pulsate they might pulsateat the wrong time or not pulsate at alland you can get a dropping pedal now ifyou get a dropping pedal and your abslight comes on that's on you there's anABS code on you got to get it scannedwith the scanner and see what theproblem is if you do have an ABS problemand does sink to the floor generallyit has to do with that entire ABSactuator module going bad in a case ofthis Lexus a new one is over 1,500 bucksso it's not something even worse you onyour worst enemy you don't want to havea problem with ABS modulator that's anexpensive problem now generally they arehard to diagnose spot often when thesego bad you will get an external leakyou'll see this assembly has fluidleaking out of it and it should be bonedry so if you see fluid leaking out ofit you know the modular starting to gobad no case you in the past I gotclusters where the pedal doesn't sinkbut they're losing fluid and you look atthat ABS module and you see it'sstarting to get a little bit wet well ifthe brake pedal doesn't sink but youlosing some fluid and you see it leakingair you don't see leaks anywhere elsehey truthfully I've had customers whenthey find out they want to spend 1,500bucks they buy canta brake fluid andwhen it gets a little low and a lightcomes on they pour some back in and theydrive them yours that way sometimes ifit's just the tiny little external leakof a gasket or something seeping hey alot of guys will just live with that andadd fluid as long as the pedals notsinking up it starts sinking yes kind ofreplace it or get another car if it'sthat expensive so now you know the fivereasons that your brake pedal can startsinking to the floor and how you can fixsuch problems or at least keep themunder check so they don't cause futureproblems or make you spend all yourmoney fixing themand here's some bonus questions andanswers William the Concord says Scottyhelped me I got an 05 ToyotaTacoma v6 it won't start and I know alittle bit all cars it has no injectorpulse and there's no ground to the fuelpump and the wires and powers or grounds are okay everyone can check help you gotno injector pulse on one of those andall the grounds and the power wires aregood unfortunately this is a rareoccasion but odds are your main computeris gone your PCM the power controlmodule is probably shot that's the onlyreason I've ever seen him not havinginjector pulse on that particularvehicle it is 15 years old now it's ararity that the computers go bad onToyotas but when they do exactly that Iworked on the Lexus a couple years agoand did the same thing and I had toreplace the main computerit just wasn't pulsing the injectorsanymore it's a rarity but even theToyota Lexus products once in a whiletheir main computers will go out and aslong as you're sure that you got powerand ground going to the computer and thewires are good odds are your computer'sgone out cuz they do every once in awhile, so if you never want to missanother one of my new car repair videosremember to ring that Bell\n"