How to Tighten A Brake Caliper Bolt

A Brake Caliper Bolt Tightening in 5 steps

A regular cause of brake system failure is as a result of brake caliper bolts failing. The issue is – in most case, because of human error. While changing brake pads is a fairly simple task, the issue happens when mechanics do not take the time to appropriately tighten the brake caliper bolts. To assist you avoid potentially catastrophic damage to your car or an accident that could cause harm to you or others, here are some simple steps on how to tighten a brake caliper bolt in 5 easy steps.

Step 1: Correctly take Out the brake caliper bolts

As with any other fastener, the brake caliper bolts functions best when they are taken out and mounted properly. Because of their location and tendency to get corroded with debris, the brake caliper bolts can get rusty and quite hard to remove. So, to lower the potential of damage, taking the bolts correctly is a vital first step. Here are 3 basic tips, but be sure to refer to your service manual for the manufacturer’s recommended steps as not all brake calipers are made from the same materials.

  1. Make use of a high-quality penetrating fluid that can absorb rust on the bolt.
  2. Allow the bolt soak for at least five minutes before trying to remove.
  3. Ensure to remove it in the correct direction. Note: While we are all taught that lefty-loosey – righty-tighty is the recommended method, some brake caliper bolts operate in reverse thread. The very reason you should refer to your vehicle’s service manual

Step 2: Check the bolt and bolt holes on the spindle

Once your caliper bolts have been taken out, and you’ve removed all brake parts that requires replacement, the next step before mounting new components is to check the condition of the caliper bolt and the bolt holes found on the spindle. There is a very simple way to determine the condition of each. If you take out the bolt and it’s rusty – throw it out and change it with a new one. However, if you are able to clean the bolt with a mild steel brush or sandpaper, it could be reused. The key is to see how well it fits inside the bolt hole found on the spindle.

The bolt should freely turn into the spindle and should have zero play as you ‘put it into the bolt hole. If you observe play, the bolt requires replacement – but, you equally need to continue to the next vital step.

Step 3: Make Use of a thread cleaner or “thread chaser” to rethread the bolt hole

If your bolt and the bolt hole did not pass the “play” test stated above, you’ll have to rethread or clean the inner threads of the bolt holes before mounting. To get this done, you’ll require a thread cleaner – commonly known  as a thread chaser – that matches the exact thread as your spindle. One helpful hint is to get a brand-new brake caliper bolt for your car and cut three small sections vertically on the bolt, and hand-tighten it slowly as it’s inserted to the bolt hole. Slowly take out this thread chaser and re-test the newly cleaned bolt hole with a new bolt.

There should be zero play and the bolt should put easily and be removed easily before tightening. If your cleaning job didn’t do the magic, stop immediately and change the spindle.

Step 4: Mount all new brake system components

After you’ve checked that the brake caliper bolts and the bolt hole on the spindle are in good frame, follow your car’s service manual and correctly mount all replacement parts in the exact procedure and order of installation. When it comes to time to install the brake calipers, ensure you follow these 2 critical steps:

  1. Ensure the new threads have thread-locker applied. Most replacement brake caliper bolts (particularly original equipment manufacturer parts) will have a thin layer of thread locker already applied to the bolt. If it doesn’t, use a good amount of a high-quality thread locker before mounting.
  2. Slowly guide the brake caliper bolt through into the spindle. Do not use air tools for this work. Doing so will likely cross-thread the bolt and overtighten it too.

Step 5: Make use of the recommended torque pressure to tighten the brake caliper bolts

This is the part where most amateur mechanics make a big mistake by searching online or asking a public forum for the right torque pressure for tightening brake caliper bolts. Since all brake calipers are peculiar to each manufacturer, and often produced from different materials, there is no universal torque pressure setting for brake calipers. Always refer to your car’s service manual and look up the correct steps for using a torque wrench on your brake calipers. If you do not want to invest in a service manual, a phone call to your local dealership’s service department may equally be helpful.

Each day more than a million brake pads are changed in the United States by qualified mechanics. Even they make mistakes when it comes to mounting brake caliper bolts. The items stated above will not 100% avoid potential problems, but they will greatly reduce the possibility of failure. As always, ensure you are entirely comfortable with this carrying out this job or you seek the advice or help of a professional mechanic.