Reverse Fluid Injection - RFI

Reverse Fluid Injection - RFI

Problem: Low activating brakes and spongy brake pedal

Cause: Air trapped in hydraulic system

Solution: RFI is a patented process from Phoenix Systems. The Phoenix Injector has been designed to perform RFI as well as pressure and vacuum bleeding. To perform RFI follow the steps below:

1. To perform RFI bleeding, first drain and clean the master cylinder reservoir. If necessary fill the reservoir before draining so an accurate measure of fluid can be taken. Note the amount of fluid removed. This will be necessary to avoid overfilling the master cylinder during the RFI bleeding process. 

2. Prime the injector and lines by pumping fluid until it fills the injector tube-instruction manual will have diagrams and details (click here for instructinal video). Once the tool is primed then begin the bleeding process at the furthest wheel from the cylinder. Connect the injection side of the tool to the bleeder valve and the vacuum side to the fluid supply container making sure it is full.

3. With the tool connected, open the bleeder screw and the slowly stroke the handle. Make sure that at each wheel you are giving at least three to four strokes.

4. Once each wheel is completed, remove the adapter from the bleeder and let the wheel cylinder or caliper burp or gravity bleed. Close the bleeder.

5. Repeat this process at each of the wheels remembering to watch the amount of fluid being used. It may be necessary to drain some fluid from the reservoir during the process to avoid overfilling it. 

6. Once complete check and adjust the master cylinder fluid level and test the pedal. If firm, test drive.


CAUTION: Never drive a vehicle with an unsafe or soft pedal.

Informative Snack
This technique involves forcing fluid into the bleeder screws to force the fluid and air up to the master cylinder (See Figure 76.1).
Air naturally wants to travel up so this technique takes advantage of this.  It can use effectively on most vehicles equipped with both ABS and conventional brakes.


Figure 76.1

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