2002 Mazda 626 ES, AutomaticFACTORY OEM SERVICE PROCEDURE

Power Brake Unit Function Check (Simple Method)

NOTE:
  • Replace power brake unit assembly as necessary.

Step 1 

  1. With the engine stopped, depress the pedal several times.
  2. With the pedal depressed, start the engine.
    • If the pedal moves down slightly, immediately after the engine starts, the unit is operating.
    • If a problem is found, inspect for damage on the check valve or vacuum hose, and examine the installation. Repair as necessary, and inspect it again.

Step 2 

  1. Start the engine.
  2. Stop the engine after idling for 1 or 2 minutes. 
  3. Depress the pedal with the usual force.
    • If the first pedal stroke is long and becomes shorter with subsequent strokes, the unit is operating.
    • If a problem is found, inspect for damage on the check valve or vacuum hose, and examine the installation. Repair as necessary, and inspect it again.

Step 3 

  1. Start the engine.
  2. Depress the pedal with the usual force.
  3. Stop the engine with the pedal held depressed.
  4. Hold the pedal down for about 30 seconds. 
    • If the pedal height does not change, the unit is operating.
    • If a problem is found, inspect for damage on the check valve or vacuum hose, and examine the installation. Repair as necessary, and inspect it again.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.