Problem: Determining the proper interval to perform a bleed and flush
Cause: Domestic OEMs do not endorse periodic bleed and flush on their vehicles.
Solution: The approach to take when determining if and when a bleed and flush should be performed will be based on the vehicle. Use the following guidelines.
European and Japanese Vehicles
The majority of vehicles made in Europe and Japan include a milage/time based recommendation for brake fluid flush in the owners manual. When supplied use the manufacturer's interval.
Domestic and European/ Japanese vehicles with no posted recommendations
There are two approaches that can be take with these vehicles.
1. Use a generic bleed and flush interval: The most universally accepted interval for performing a bleed and flush is 2 years or 24,000 miles. Ask the customer if they have had a flush performed in the last 2 years of 24,000 miles to qualify them as a potential flush customer.
TIP: You cannot determine the condition of the brake fluid by its color. Some new brake fluids have additives that pull some of the dye from the rubber seals resulting in discoloration. A fluid's color cannot be used to determine its ability to perform its function.
2. Use one of the various brake fluid test technologies to determine the need for a flush. There are several brake fluid test technologies available.
Phoenix Systems Recommendation: For many years the professionals have recommended moisture testing as the best measure of defective brake fluid. Phoenix Systems has revolutionized the industry with a copper brake fluid test that measures the copper contamination in brake fluid. Copper corrosion has been known to damage important ABS and brake system components, making the copper test the best measurement to determine the effectiveness of your brake fluid.
BrakeStrip is the only brake test strip that will measure a vehicles copper corrosion levels. Recommended by NUCAP, OMNI, Raybestos, and Bendix, BrakeStrip follows MAP guidelines to give you clear, repeatable, and reliable proof of the level of corrosion in any vehicles brake fluid. BrakeStrip takes a simple three step process: Open master cylinder, dip BrakeStrip in brake fluid and compare the strip to the color scale to determine the level of corrosion in your system (See Figure 73.1). If corrosion levels exceed 200ppm, then it is suggested to perform a brake fluid flush. It is recommended to use this simple test at every oil change to accurately determine brake fluid safety.
Figure 73.1
https://www.brakebleeder.com/products/best-sellers/brakestrip/
