Learn the signs of a leaking rear axle seal and what to do if you find this problem while replacing the brakes. This article and video covers why it’s not recommended to install new brakes if you have a leaking rear differential or axle seal, and how to fix this problem yourself.
4 Signs You Have an Axle Seal Leak
1. Differential Fluid on Brake Parts
Axle seal leak aren’t always easy to find and it may not be obvious that you have one. You might only discover this after maybe ordering brake parts from us and while using our how-to videos to remove your brakes, you find differential fluid on a brake part like the brake shoes.
2. Smoking from the Brakes
Smoking brakes is one common sign of a differential or axle seal leak. You may notice the smoke while or after driving.
3. Stinky Smell
You might smell an abnormal stinky smell in the air after driving if the differential or axle seals are leaking fluid.
4. Debris on the Backing Plate
If there’s a noticeable size of debris on the backing plate, that is a common sign of an axle or differential seal leak. You may also find leaking behind the brake rotor or, worse, the emergency brake shoes.
Why Should I Not Use My Brakes If the Rear Axle Seal Is Leaking?
It Can Worsen Braking Performance and Make Driving Unsafe
The gear oil can cause problems with braking if it lands or brake parts. Fluid leaking onto the brake shoes, for example, can swell the brake pad material. If differential or axle fluid is leaking onto the shoes, they could hit up against the rotor, causing friction, heat and possibly smoke from the brakes.
A Leaking Rear Axle Seal Can Damage Brake Parts
If axle fluid is leaking onto the brake shoes, it it could also loosen the adhesive keeping the shoes together. The friction material could break off from the brake shoe and bind up inside the rotor. That could create a dangerous situation where the wheel has seized.
Difference Between Leaking and Seeping Fluid from a Rear Axle or Differential Seal
No Signs of Excessive Fluid Leaking
If you find fluid is seeping from a differential or axle seal, you might only have to replace the seal. You won’t need to replace the brake parts if no fluid leaked onto parts like the emergency brake shoes and they’re in good condition.
How to Replace a Leaking Rear Differential or Axle Seal
If you find you have to replace the seal, you’ll also want to inspect the bearings behind it.
If there’s a big leak, you’ll need to replace the emergency brake shoes if they’re damaged along with a new axle seal. You definitely want to replace the emergency brake shoes if fluid leaked onto them.
Generally, axle seals are moderately easy to replace. However all vehicles are different and this can affect what the steps are and how difficult the repair will be.
Typical steps for an Axle Seal Replacement
- Remove the wheel
Loosen the lug nuts with the vehicle on the ground. Raise and secure the vehicle with a jack and jack stands. Remove the lug nuts and remove the wheel and tire.
- Remove the Rear Brakes
- Remove the Differential Cover and Drain the Fluid
Loosen the bolts from the differential cover, leaving one loose to drain the fluid. Pry the cover with a screwdriver to loosen it. Drain and recycle the fluid.
- Remove the Axle
Remove the locking clip from inside the differential that’s holding the axle in place. Carefully remove the axle.
- Remove the Axle Seal, and Clean and Inspect the Differential
Remove the axle seal. Clean and inspect the differential. Make sure the bearing is not damaged
- Add Brand New Seal Lubricant and Reverse These Steps
Put on brand new seal lubricant before reversing these steps and reattaching the removed parts.