Hydraulics Archives - Page 3 of 9 - UnderhoodService
Tech Tip: Erratic Fluid Level Readings/Filler Tube Leaks in Ford Vehicles

Vehicles affected: Ford: 2000-’07 Taurus and Windstar; 2004-’07 Freestar; Mercury: 2000-’05 Sable; 2004-’07 Monterey

Tech Tip: Toyota Corolla and Matrix Front Brake Rattling Noises

Some customers may experience a front brake rattling noise when their Corolla or Matrix traveling over bumps. Updated front disc brake cylinder (caliper) mountings and disc brake pad support plates are available to eliminate this condition.

Tech Tip: Honda CR-V Rear Brake Grinding, Thumping or Groaning Noises

A customer may complain of a grinding, thumping or groaning noise coming from the rear brakes. This occurs during the first several stops after the vehicle has been parked overnight. Under normal braking, corrosion from the disc surface is not quickly removed, allowing for a temporary grinding or thumping noise. A new brake pad is now available, which has improved corrosion-removal characteristics.

ASE-Certified Technician in Oklahoma Reports Seeing More Vehicles with Rusted Brake Lines

A news story on KJRH-TV Channel 2 in Tulsa, OK, profiled a local driver who experienced a loss of brakes that was attributed to a rusted brake line that snapped. A local ASE-certified technician told the reporter that he is seeing more and more vehicles with rusted brake lines. Are you seeing this same trend at your shop? Let us know.

Latest Toyota Recall Due to Replacement Brake Fluid and OE Seals

Toyota Motor Sales announced it will conduct a voluntary Safety Recall for a brake problem that occurs once the vehicle has been serviced with non-factory fill/genuine brake fluid. Drivers may experience a small amount of the brake fluid leaking from the brake master cylinder, resulting in illumination of the brake warning lamp.

Tech Tip: BMW Brake Pad Warning Light On After Brake Pad Replacement

You may get a customer complaint that the brake pad warning light comes on after the rear brake pads have been replaced. After replacing the pads and wear sensor, turn the ignition on and wait for at least 30 seconds, then start the engine. If the pad wear circuit is good, the light should go out with no further procedures.

Tech Feature: Brake Job on Chrysler Sebring

The Sebring was replaced with a new model based on the JS platform for the 2007 model year. There are several brake packages available featuring either a disc/drum combination or a disc/disc combination. All models are equipped with five possible brake system options.

Tech Tip: How to Bleed Slave Cylinders Without Bleed Screws

Technology is constantly changing and hydraulic release clutch systems are no exception. It is not uncommon for once familiar features to disappear from new vehicle models, replaced by “new and improved” designs. This changing landscape can cause confusion, and occasionally result in damage to system components when technicians mistake new features for old ones. Hydraulic slave cylinders without bleed screws are a perfect example.


Harold Unikel of Power Brake X-Change, of Pittsburgh, PA reminded my why it is so important for technicians to be able to understand the brake math basics. I made a mistake while editing the equation for calculating the surface area of a circle which is πR2.

BRAKE MATH: PSI & Clamping Forces What happens in the real world?

In our last installment of Brake Math, we demonstrated how 70 lbs. of force on a brake pedal can result in 556 psi of brake fluid heading to the calipers. So how does this pressure stop a car? Next, we we look at how PSI is turned into “clamping force” and the math behind it. Also, we will look at the implications it has on friction materials and caliper design.

Brake Tech Tip: It May Be Time for a Complete System Flush

With a customer complaint of a fading brake pedal, most technicians automatically assume friction as the culprit. Installing a new or different type of friction formulation may not satisfy the pedal fading symptoms, especially if the brake fluid is contaminated.

Tech Tip: Reverse Bleeding Basics

Many vehicles can develop release problems after a clutch change or replacement of the hydraulic release system components; usually consisting of a clutch master cylinder, slave cylinder and line. Conventional bleeding is usually done by opening the slave cylinder bleeder valve and either gravity bleeding or pumping the clutch pedal while opening and closing the slave bleeder valve.