How To Inspect The Brakes On A Full Float Axle

Do you have a full float axle with drum brakes? If so, you may be aware that it is time consuming to inspect your brakes. If you’re wondering how the process goes, you came to the right place.

A Full Float Axle Drum Brake Inspection Tutorial

Read on to find out how to inspect the drum brakes on your full float axle.

Taking Apart The Hub Assembly

To access the drum brakes on most full float axles, you need to take apart the hub assembly at both ends of the axle. Here’s how the process goes:

  1. With the truck on the ground, loosen up the wheel lug nuts and the axle bolts. Don’t remove them yet.
  2. Lift the rear end of the truck just enough to get the weight off the wheels.
  3. Remove the lug nuts.
  4. Remove both rear tires. If you have dual rear tires, remove both tires at each end.
  5. Place a catch pan under the hub. It will probably leak a small amount of oil.
  6. Remove the axle bolts and then take out the axle.
  7. Next you will need to remove the special locking nut (or nuts). Some axles use a clip and a lock pin also. Some require a special socket.
  8. Once you have the bearing retainer nuts off, you can remove the drum and hub assembly.

Inspecting The Drum

Now that the drum is off, inspect it for the following issues:

  • Hot spots
  • Glazing
  • Deep grooves or gouges
  • Rust on the friction surface
  • Cracks

If any of these issues are present, replace the drum. That, or use the opportunity to swap to disc brakes. Skip ahead to the last section of this post for more information on this. If you’re replacing the drum, be sure to replace the drum on both sides. Even if the drum on the other side is OK, it’s still a good idea. This ensures even braking performance on both sides. Also make sure the replacement drum is perfectly round. Often new drums are very low quality since they are considered outdated technology.

Checking The Brake Shoes And Drums

Next, check the brake shoes. You want to make sure that they have enough friction material to last a while. The minimum thickness of a brake shoe varies depending the application, so there is not an easy rule of thumb. In general, heavy duty trucks require more minimum shoe thickness than light duty trucks. Your best bet is to see what the service manual says. If you don’t have one available, try and compare your shoes to new shoes. If they are more than 75% worn, you should replace them.

If your shoes have rivets to attach the lining, you want to have at least 1/8″ of lining above the top of the rivet. You can use tire depth gauge to measure this. Most brake shoes use adhesive to attach the brake lining these days, so if you see rivets, your shoes are old.

Also look for cracking on the lining. Cracking on the lining is caused by overheating, and if you see, you should replace the shoes. Cracked linings can disintegrate, and cause the drum to lock up.

It’s a good idea to check the thickness of the drums, too. Check the service manual to see how much thickness is safe. The maximum diameter is supposed to be on the drum, but sometimes it can be hard to find.

If your drum brakes still look good, clean the drum and brake pad hardware with brake cleaner. This gets rid of the dust buildup, thus keeping your truck’s stopping power optimal. The biggest failure point are the small parts in the drum. Take out the adjuster and make sure it turns freely and lubricate it properly. Make sure the cable that goes from it to the top of the adjuster to the top of the drum brakes is properly in the saddle on the side also. Check for rust on the springs. If they look rusty replace them while you have it apart.

Inspecting Disc Brakes Is So Much Easier

Conversion kit 1

Disc brakes are so much easier to inspect than drum brakes. It’s because you only have to remove the tire. Some calipers come with a window that allows you to check the brake pad thickness without needing to remove the caliper too.

To check your disc brakes, you would only need to:

  • Measure the brake pad thickness
  • Check the rotors for any:
    • Scratches
    • Hot spots
    • Glazing
    • Deep grooves or gouges
    • Warping
    • Rust
    • Cracks

Even Swapping To Disc Brakes Almost As Easy As Repairing  Drum Brakes

Bolt swap 2

We offer disc brake conversion kits for full float axles. Converting to disc brakes with one of our kits is a straightforward process. If you’ve got to do a full rebuild on your drum brakes, including replacing the drums, cylinders, adjusters, springs, shoes, etc, you’ll find that converting to disc brakes doesn’t take much more time. And depending on how expensive new drums are, converting to disc brakes may cost less.

Disc brakes offer so many more benefits over drum brakes. For instance:

  • Disc brakes are much easier to check and maintain
  • Disc brakes offer better stopping power
  • Disc brakes are much lighter

You’re welcome to contact us if you need help finding the right disc brake conversion kit for your full float axle.