Dodge Ram: Brake Diagnostic Guide

Not only can a malfunctioning brake system be scary, but it can be downright dangerous for you and other drivers on the road. If the brakes on your Ram truck have become faulty or are not quite working as good as they used to, take a few moments to properly diagnose the problem for the safety of all those on the road.

By Joseph Coelho - July 10, 2015

This article applies to the Dodge Ram 2nd, 3rd, and 4th Generation (1994-Present).

The brake system in a Dodge Ram is a critical element that requires regular service and maintenance to provide reliable stopping power. When brake components tend to wear or fail, there are some telltale signs that can be caught early enough to prevent larger repair bills down the road. Failure to heed the warning signs your truck may be sending you can result in a brake system failure and potentially an accident. Fortunately, most faults in the brake system are easily spotted and can be repaired by the shade tree mechanic relatively quick. This article will cover some of the signs and symptoms of common brake component failures related to the 2nd, 3rd, and 4th generation Dodge Rams.

Materials Needed

Floor jack
Jack stands
Tire iron
Flashlight

Step 1 – Check for brake fluid leaks

Pressing the brake pedal applies pressure to push the master cylinder piston forward, and transfers the brake fluid to each of the four brakes via the brake lines. The fluid then pushes on the caliper pistons as well as wheel cylinder pistons to place the brake pads and shoes in contact with the rotors and drums, thus stopping the vehicle. A leak anywhere in the brake system will disrupt this process and allow the brake pedal to sink to the floor, therefore not allowing the truck's brakes to operate correctly.

Master Cylinder: The first and easiest place to inspect for a brake fluid leak is at the master cylinder, which is located under the hood in the engine bay. The master cylinder is located on the driver's side firewall. Leaking brake fluid will often pool around the brake booster and can easily be spotted. A leak is usually indicative of a seal that has gone bad inside of the brake master cylinder. The bad seal is allowing fluid to bypass the piston and reduce braking effectiveness when the brake pedal is pressed down. While the master cylinders can be rebuilt, it is common to replace the whole master cylinder assembly with a new unit. If no brake fluid leaks are present at the master cylinder, the leak is likely somewhere downstream in the brake system. A low fluid level at the brake fluid reservoir often accompanies a leak.

Figure 1. Inspect for leaks at the master cylinder.

(Related Article: How to Replace Master Cylinder - DodgeForum.com)

Hard Lines: The next areas to inspect are the hard brake lines running from the master cylinder to each brake. A common problem for the 2nd generation Ram trucks, in particular, involves these hard lines splitting or rusting out. Depending on the ride height of your truck, it may be necessary to lift it and support it with jack stands to allow adequate room to slide under the vehicle for inspection. Trace the hard brake lines from the master cylinder to each wheel. The lines typically run along the frame rails, crossmembers, and the rear end to provide support. Look for any wet, corroded, or damaged lines that may be allowing the fluid leak. New hard lines are available pre-bent and ready for installation. Similarly, tubing can be bought, bent, and flared with the proper tools if you are looking to save some money.

Figure 2. Example of rusted out brake line leaking fluid.

Flexible Rubber Hoses: If all of the hard lines check out okay, examine the flexible rubber brake lines at each brake. These rubber hoses connect the hard lines to the brake calipers/wheel cylinders. The hoses allow the truck's suspension and steering to constantly move around, while maintaining a sealed brake system. Unfortunately, like many other rubber components, the brake hoses will crack as well as split from age and weathering. Additionally, it is not uncommon for road debris to damage a rubber brake hose. If one hose is found to be leaking, it is usually a good idea to replace the whole set as they are all likely worn out.

Figure 3. Flexible rubber brake hose inspection.

Caliper and Wheel Cylinders: The final area to inspect for a brake fluid leak is at the brake calipers and wheel cylinders. Both of these components have rubber seals and O-rings that can break down or tear, allowing brake fluid to seep. A leaking brake caliper is easily spotted since the caliper body is exposed inside of the wheel and will be wet with fluid. A severely leaking wheel cylinder on the rear drum brakes will often leave a wet puddle down the rear side of the backing plate, or the bottom of the brake drum. A newly developed or minor wheel cylinder leak may be a bit more difficult to spot, and will typically require removal of the drum for inspection. Both calipers and wheel cylinders are readily available and can be replaced with basic tools.

(Related Article: How to Replace Brake Pads, Calipers, and Rotors - DodgeForum.com)

Pro Tip

If you have replaced any of the components listed above, bleeding the brake system is mandatory to restore brake functionality.

If you have a firm brake pedal but are experiencing a pull to one side or hearing a noise while braking, continue to Step 2.

Step 2 – Inspect the calipers, rotors, drums, and shoes

Symptoms such as pulsating, squealing, or a pull to one side often points to a brake caliper, rotor, drum, or shoe.

Brake Pulsation: A pulsating brake pedal when applying the brakes is usually caused by a warped brake rotor or out-of-round brake drum. The pulsation can be accompanied by a shudder or jerking when slowing down. The irregular brake surface causes the pads or shoes to move back and forth against the drum or rotor when braking. Thus, transferring this force back through the brake pedal and causing the strange vibration. When inspecting the brake rotors and drums, look for hot spots or glazing, which are indicators of warping. In severe cases they can be felt by running your hand over the braking surface, or be checked with a dial indicator. Minor irregularities can usually be corrected by turning or resurfacing the drum or rotor, while severe cases will require new parts be installed. If continually experiencing glazed or warped front brakes, ensure the rear brakes are properly adjusted to prevent the front brakes from overheating. Similarly, the proportioning valve, which regulates brake pressure to the rear brakes, may be malfunctioning. However, this will usually be accompanied by a brake warning light on the dash.

Figure 4. Measuring the brake rotor for warping.

Brake Squeal: An abnormal high-pitched brake squeal is usually an indication that the brake pads are nearing the end of their life and should be replaced soon. The brake pads often have a small metal tang that comes in contact with the brake rotor while coming to a stop. The result is a high pitched squeal to warn the driver of the brake pad condition. In severe cases, a low pitched grinding noise will surface when all of the brake pad material is gone and the metal backing of the brake pad is coming into contact with the rotor. At this point, the rotor will become damaged and need to be replaced along with the brake pads. A completely worn brake pad can also be extremely dangerous as your stopping distance will greatly increase, and you may also experience a pull to one side when trying to stop.

Figure 5. Brake pad wear indicators.
Figure 6. The severity of brake pad wear.

Pull to One Side: A pull to one side while braking is an indication that one of the brakes is not working properly. The Ram truck utilizes a sliding brake caliper that pinches the rotor when the brakes are applied. Occasionally, these calipers can seize up and either constantly drag or not apply any braking force when the brakes are applied, causing a pull to the left or right. As mentioned above, a pull can also be caused by worn or damaged brake pads and rotors. Similarly, a braking surface contaminated with oil or grease can change the coefficient of friction on a particular corner and cause a pull. Rubber brake hoses that have failed internally have also been known to cause a brake pull. A small piece of separated hose can obstruct the flow of brake fluid to the caliper/wheel cylinder and cause the brakes to stick or not be applied at all on the said brake. Finally, a stuck or frozen adjuster in the rear brake drums can prevent a brake from operating normally and cause a pull. Besides an internal failure of a rubber brake hose, most of these items can be easily identified by visually inspecting the brakes.