How to Replace a Fluid Level Sensor

What You'll Need
New sensor
Needle nose pliers

The brake fluid level sensor in a vehicle monitors the level of the brake fluid and alerts if you if goes below a certain level. This lets you know that there’s a problem in the braking system. Having a working sensor can keep you safe and also lets you have the system repaired before it becomes extremely costly. Replacement of the brake fluid level sensor is an easy job, although the part can be hard to find.

Step 1 - Preparation

Have your service manual to hand so you can find the location of the brake fluid level sensor in the engine compartment. It should be right by the brake fluid master cylinder. With the hood up, use your wrench to disconnect the negative battery cable.

After finding the sensor, you have to disconnect the electrical connection that runs to it. This should be a clip that can be eased off gently. Lay it aside.

Step 2 - Removal

The sensor itself is held in place by locking tabs. Use your needle nose pliers and compress the tabs, which are on the inboard side of the brake master cylinder, to release the sensor. Carefully lift it away.

Step 3 - Replacement Sensor

The replacement sensor needed will vary between makes and models of vehicle. Before undertaking the work go to your local auto parts store or dealer and buy the correct replacement. Never try to use a different sensor as it won’t fit and won’t work properly.

Step 4 - Installation

Push the new fluid level sensor into place. You’ll know you’ve positioned it correctly when the tabs lock into place around it. Gently test it to see if you can pull it away. If you can’t, then the fluid level sensor is firm in position and you can move on.

Now you can reattach the electrical connection, being sure the clip fits firmly on the tab of the sensor. Reattach the negative cable to the battery to complete the job.

Step 5 - Different Models

Although replacing the fluid level sensor in many types of cars and trucks can be accomplished this way, there will be variations according to the make of car. Before starting the job, inspect the fluid sensor to determine how it’s connected and use the appropriate tools and procedure to remove it and install the new one.

There should be no need to bleed the system when replacing the fluid level sensor. However, if your brake fluid is low, rather than simply topping it up you might want to consider bleeding the entire system to ensure that it works properly. There have been instances where people working on vehicles have snapped off the sensor close to the cylinder and simply use superglue to reattach it without any problem. Be aware, however, that this won’t always work and it can be easier, although more expensive, to replace the sensor completely. For long-term safety, replacement is definitely the recommended course.