Top Ten Brake Job Mistakes For Pads, Rotors and Calipers

Here are the top ten brake job mistakes made by rookie mechanics when replacing brake pads, rotors and calipers.

Wheel Studs

1. Not cleaning the brake slides and hardware: Just slapping new pads where the old pads once resided never works. The slides and abutment clips should be cleaned and/or replaced.



Brake hardware bolts2. Not lubricating the guide pins: Caliper guide pins on floating calipers should be cleaned in solvent and new grease should be applied. The grease is under extreme heat and pressure so always use a caliper specific grease. NEVER put a torn boot back on a car.


backwards brake pad3. Installing the brake pads backwards: It happens more often than you would think!





brake rotor measure

4. Not measuring the rotor: Rotor thickness needs to be measured every time. Running a rotor that is below specifications can cause safety issues like cracking and fading.



brake rotor machine5. Not machining the rotor: New pads almost always require a fresh rotor surface so the pads can deposit a thin layer of friction material to increase braking performance. If old deposits of the previous material are on the rotor, it can contaminate the new pad and lead to performance and noise issues.

caliper:bracket:bolt6. Not properly torquing the caliper bracket bolts: Not all caliper bracket bolts are the same. Torque ranges can vary from 30- to 110-ft/lbs. Also, some bracket bolts can be torque-to-yield or require liquid tread lockers.



Caliper Guide Pin Bolts7. Over torquing the caliper guide pin bolts: Caliper guide pin bolts typically need a 13mm wrench to remove. It is a rookie mistake to go nuts on these bolts and break the heads off. Typically these bolts require only 25- to 35-ft/lbs of torque.  Be gentle!


Brake Bleeding 8. Installing a caliper upside down: Nothing is worse than going to bleed a new set of calipers on a vehicle, only to find the bleeders are on the bottom of the caliper and not the top. The bleeder needs to be at the top of the caliper to remove all the air. Always check the box to make sure you have a left and a right before you start the job.

Nucap NRS9. Using cheap brake pads: This is the most common mistake for the rookie is to shop for a pad on price and not quality, features and reputation. Features like NUCAP’s NRS mechanical retention system, Clip-on/floating shims and extras thrown in the box like abutment clips do not come cheap, but the can mean the difference in the long run.

 hanging brake caliper10. Hanging the brake caliper by the hose: Nothing is more painful than to watch a brake caliper do a bungee jump from a control arm or knuckle and watch it dangle by the brake hose. This can cause damage to internal structure of the hose that can cause a soft pedal or a rupture.



What was your biggest mistake while doing a brake job? Please share in the comments!

  • Denver Davis

    First time I’ve ever done pads & rotors with no assistance, but after driving (slow) for a short trip home, the noise coming from the front pass sounds suspiciously like I put the damn pads on backwards (sounds like a thumping sound that ONLY appears when braking). I’m praying that I’m not that stupid, but we shall see.

    • Austin

      I did not think I was that stupid but I did this the first time I changed my pads and it scratched up my rotors! Don’t drive ANYWHERE until you check that!

  • Christina Page

    Question? Everything went well with all 3 other brakes, but then my husband gets the passenger right and the bolt in the bracket won’t move. We keep getting different answers everywhere. We need a new bracket, we need the bracket and calibure, we just need to spray it with cleaner. That’s just a few. What it’s the right way? Please help

    • John Goldston

      Use a good penetrating oil and soak the bolt first (PB Blaster, WD-40 Specialist.) Then, try loosening with a long wratchet wrench or breaker bar. If none is available, a length of pipe slipped over the handle of wrench will make a “cheater” handle that increases leverage.

      If a no go, try tightening the bolt very slightly to break up the corrosion. If it doesn’t release, let it sit for several hours (overnight is best), while gently tapping the bolt every several hours. If that doesn’t work use a propane plumbing torch to CAREFULLY apply heat ONLY to the bolt, being sure to avoid any rubber items or other items that are flammable.

      Good luck!

      • Christina Page

        Thank you!! We ended up buying the new bracket and calibure so all is well now!!! Thank you again

      • metrangia

        Heat from a propane torch works for me.

      • mike p

        You apply heat to the bracket around the bolt. Metal expands when heated, it doesn’t contract. But Johns answer is definitely the right one.

    • mike p

      Use a breaker bar, if the bolt snaps, then you get a new bracket, but usually the bolt breaks…loose, that is.

  • Oingo Boingo

    Mistake was thinking that I am just going to do a pad and guide pin bolt clean and lube and found my rotors have chunks of rust falling out and the pads backing plate has rusted off. I should have have the rotors and pads ordered (It takes a bit or work to get the Raybestos performance series stuff in Canerduh, heckspensive too Now I have to do it all over, oh well good practice.

  • Ever

    I paid a lots of money for my breaks to be done. At Active Green Ross in london 615 Oxford Street. The break pads fall off. I almost had in a accident

    • Jen

      So what did the company do for you?

    • Drew

      What are “breaks”?

  • Libby Ramos

    It is all too common for the home DIY mechanic to let the caliper hang by the brake line! You definitely want to keep it supported with something while doing a brake service job.

  • David Chavarria

    Im sorry to revive an old thread but this is my current issue. I have a 07 Nissan Titan. The front brakes were squealing louder than a pig. The truck pulls to the right as you press the brakes. When I turn to the left, you can hear squealing, but no grinding. You also hear minor squealing when backing up and turning the wheel to the right. So I replaced the pads only. The pads themselves looked good. There were about half way worn with no weird worn out pattern, it was all even on both front tire pads. I cleaned out the caliper from rust and dirt. Checked boots for mounting pins, cleaned and greased them. Installed new pads, with new abutement clips. Plus a thin layer of break grease to the back of the pads to keep them from vibrating. The problem is that I am still getting the squeal. I shook the wheel to see if it maybe the wheel bearings. Those are good. So what maybe causing the squeal. Any suggestions would be greatly appreciated. Thank you.

  • Mike McClelland

    biggest mistake was using a defective torque wrench on the caliper bolts . . . broke one right off.

    • Michael John Wilson

      i dont bother torqueing up caliper bolts i am a mechanic or auto technician and have done hundreds if not thousands of cars and their brakes over the last 17 years, only ever had one bolt ever on a caliper come loose over time all it does is make the brakes clunk is all its no big deal, i have natural torque in my wrists, i will tell you something though the torque wrenches need recalibrating every now and then if they are the turn type torque wrenches also if you have torque wrenches just thrown around really rough they will lose their calibration they are a sensitive tool, i have torque wrenches that are out of calibration and still work effectively, torque wrenches even out of spec i would not really think they would brake a bolt, more than likely you got your torque setting wrong or you set the torque wrench wrong in the first place,

  • Nahin Obregon

    Hi guys I need help with a little something, about 3 weeks ago I had my breaks changed at the shop, I hadn’t been driving my car cause I was catching a ride with a friend to work, so last week I finally take my car to work and on my way home the breaks started to sound terribly… When I get home to check the caliper was open , it appears as if they forgot to put the bolt back on the caliper. So I went ahead and looked for the bolt myself at an auto parts and put it on the caliper. Now that I’m testing my car it continues to make grinding sounds and it’s starting to break on its own… Who can help me??? Can it possibly be that I bolted it to tight ??? Plz help

    • Drew


      • Alice

        Why don’t you answer the question instead of being a dick correcting the spelling ?

        • Drew

          I didn’t correct the spelling.

        • Drew

          I didn’t correct the spelling.

      • George

        How tiny is your penis that you waste time pestering multiple people about spelling mistakes?

        • Drew

          How did you know mine is only 2″ longer than yours?!?

        • Tom Ruso

          lol that was awesome

    • Michael John Wilson

      okay here it is for you loud and clear if you have your car sitting around for long periods of time your rotors start rusting, among other things also your rear main seal between your motor and your gearbox/transmission will get hard and start leaking, cars do not like sitting around for long periods of time it sounds like you have rust accumulation on your rotors you need to take your car out do some rigouress braking to remove the rust, next time you get a bolt for your caliper take the bolt from the other side of the car the capliper bolt to match it up with the bolt in the exacrt same position and just go to a nuts and bolts shop, you dont need a specific bolt from rip off auto parts stores, then you put locktite on the bolt, it may well be that the mechanic did do the bolt up but it worked its way loose from no loctite, , if also the workshop you did take your car to only changed the pads and machined the rotors of which i never do because it weakens the rotor and rotors are not that much dearer to do DONT EVER MACHINE YOUR ROTORS ITS A WASTE OF TIME unless its a very rare car and parts are hard to source, you can not , over tighten the bolts on your calipers that they cause the car to brake on its own i have never heard of such a thing and is illogical in thinking, my bet is you have rusted rotors from car sitting and or the rotors were machined which is a huge waste of time and money, possibly the other thing is your caliper is stuffed and you need a new caliper, sometimes calipers sieze up from your brake fluid not being changed regularly, brakes and brake systems in cars are really simple not much to them, i could tell you about ABS and cycling the ABS modules etc… but thats another story, im an auto-technician of 17 years

  • Mike k

    Most pistons need to be pushed back into the caliper in order to accommodate the new rotor and brake pad. I use a large c clamp. On one brake job I found the Pistons didn’t push back in at all. They “screwed” back in. That was a first. I believe it was on a 80s Pontiac.

    • Michael John Wilson

      a lot of cars have screw in pistons usually on the rear brakes i find them a hassle, however lots of cars have this system seen it on nissans, fords a few different cars

  • Andrew

    I’ve been doing my own brakes for about 5 years now. I offered to do my friends for him. Apparently,I didn’t tighten one of his bolts enough and his right front wheel locked up while he was driving. I could have killed him. I feel horrible.

    • Michael John Wilson

      yes but that doesnt happen if you have a loose bolt usually all you hear is clanging noises i have done work and bolts have worked themselves loose and i had also when i was younger other mechanics forget to put bolts back on the calipers and nothing really happens except for clunkiing noises , i actually dont believe your friends car locked up, sounds like your friend is talking BS, and if you are thinking that i talk BS i have been an auto technician for 17 years pre-engineering level

      • Guy Tysick

        Really, 17 years and you don’t think this could happen. 2013 Chrysler Town & Country was bought from a dealership, 300 miles after they replaced the rotors and pads the top bolt fell out,I hit the brakes gently on the off ramp,van started to shake,steering wheel vibrating,loud grinding ,maintained a firm grip and continued stab braking off and on,made it to the end of the ramp, 5mph the front passenger wheel locked up. The caliper had made a nice grove around the aluminum before lodging itself in the spokes. The caliper and bracket flipped forward and was working itself off the rotor into the rim. If I would have hit the brakes on the highway doing 70mph, I believe it could have been worse. This was not a caliper bolt in the caliper, it was the bracket bolt that the caliper mounts to.

        • Michael John Wilson

          i actually hate cunts like you that decide that the years i have worked hard on cars mean nothing , why dont you go jump off a fucking bridge arsehole because you obviously can not read properly, the thing is that your an arsehole and for new years your the first arsehole of the year congratulations, cars dont lock up without warning noises i didnt say they didnt locked up i dont believe the story that there was no warning and i dont believe people can get killed because of a loose bolt in the caliper hence the reason i dont believe the story its highly unlikely that it happens without warning or are you just a first sentence sort of arsehole that only reads one sentence and starts judging like the fuckwit he is?, but you yourself know there is warning because you continued to drive your car as you have said even though it was making terrible noises, why dont you fuck off douchebag go be an arsehole on someone elses time! im glad im not a condesceding arsehole like you that believes all he can do is not realise mechanics make mistakes just like you make mistakes everyday, but thats not good enough for you when a mechanic takes precious time out of his day to explain fundamentals to you, fuck you and your comments doubting my experience mate i can do computer diagnostics on your car and watch your head spin that quickly with a solution, i have worked on thousands and thousands of cars you arsehole SO GO FUCK YOURSELF, its one of the reasons i am now giving up the trade because of dis-empowering fuckwits like you that come along time and time again we work on all your pieces of shit keeping economysw going and you talk to us like we are pieces of shit, your a FUCKHEAD now if you will excuse me im going for a 10klm bicycle ride before i grab one of my automotive customers and start smashing his head in, did i tell you i have my own automotive buisness, fucking clueless cunt

          • Guy Tysick

            This is a prime example why we have mental help, for people like you. Yes, you did say that you don’t believe calipers can lock a wheel up. You need to re read what you wrote. Hopefully your customers see that you would like to smash theirs heads in and report you to the proper authorities. Make sure you put your helmet on while riding that bike, you don’t need anymore brain damage.

          • Michael John Wilson

            i actually do have a mental illness their is something wrong with my brain had it since i was 17 im am 43 now and fucking you think i fucking care what you think, i have been in ten psych hospitals when i was younger breifly went to prison once, schizo-effective , bi-polar , i also am a fully qaulified carpenter i studied engineering, i studied buisness, i have my own buisness, i invest money i have more money than mud, go have a fucking cry you new years day fuckwit

  • Tom Ruso

    just changed my moms brakes after her complaining about the brakes not feeling right. the dumbass mechanic installed some brakes with about 30% less pad material than the duralast components used to replacd them. Now the braking feels like a sports car it was a 2008 fx35. be wary of bad mechanics, there are more than you would think

  • Christopher Colangelo

    I replaced pads and rotors on a Chevy Tahoe with aftermarket performance rotors (drilled and slotted) and ceramic pads. The new rotors are a little thicker then the OEM rotors. The rear is good but, the front is creating a lot of dust and odor. There is no noises being made All parts were cleaned, lubricated and torqued properly. Any help would be appreciated.

    • Joe

      Sometimes you will notice some smell, or a little smoke on first test drive from breaking in with ceramic pads but should pass after driving a bit. On having excessive brake dust I have to wonder if you lubed your guide pins to make sure you dont have a frozen pin which may cause a brake pad to stick. Also possible sticky piston but I think you would notice on compression of piston when installing pads. Hope that helps.

  • Taylor nemeth

    I put both outside pads with the matal clips on one rear side and the inside ones on the driver rear lol would this make a big differenc? I had a squishy pedal before this and bleeding and now it squishes nd sounds like air in hydraulics when i push the brake half way down easily than it starts vraking normally any suggestions? No master cylinder or brake booster leaks not even the one to the intake no fluid loss if so its very very very little, pulls slightly to the left when driving slider pins are well greased and move calips compress well, i have a 04 grand am nd it even feels like breaks slightly stick when driving car feels heavy after stops noticed it when i put it in drive from parking and the car barely moves when any car ive had or when i bought this it moves like a fast walk or a jog, idk what it could be

  • nick

    just put new ceramic pads on 2010 chevy express 2500 van fronts and rears..Rotors looked very brakes fine,no sticking but now the rears smell and get hot,so we took the wheel off again and see the rotors are blueish in color,could bottom slides be sticking?they didn’t move like the top bolts.

  • Paula Kennedy

    Hello my name is Brian, shade tree mechanic. We put rotors and pads on my son an laws 05 300 and noticed the wheel bearing on passinger side was going bad so we replaced that. The drivers side wheel spins fine. But, when i put the caliper with new rotor, bearing, and pads the rotor will not spin freely. i have never incountered this problem before so we are quite dumbfounded. in order for us to drive the car i put one of the better old pads on and a new on, it spins freely and brakes great. My question is why would one side work and not the other? The bearing, the pads or the rotors?

    • mquan

      sounds like the caliper piston may not have been pushed back in far enough? brake pad was probably rubbing the rotor making the wheel not spin freely. the old pad worked because it was worn down enough to allow enough clearance to allow the wheel to freely spin.

  • Justin Brooks

    Driving with the passenger brake caliper off the car completely

  • Chuck Webb

    Remove some fluid from the reservoir prior to pushing piston back into the caliper. Fluid will need room to return to the reservoir for this process.