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.

  • 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?!?

  • 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.

  • 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.