Bleeding drum brakes with a Mityvac vacuum pump is an efficient, one-person method to remove air from the brake lines. Here's a step-by-step guide:
Mityvac vacuum pump kit (MV8000 or similar)
Brake fluid (correct DOT type for your vehicle)
Clear plastic tubing (fits bleeder valve snugly)
Wrench (to open/close bleeder valve)
Clean rags (to catch spills)
Safety glasses & gloves
Ensure the master cylinder is filled with fresh brake fluid (keep it topped up during bleeding).
Locate the brake bleeder valve on the drum brake wheel cylinder (usually on the backside).
Clean the bleeder valve to prevent contamination.
Attach the clear plastic tubing to the Mityvac’s nozzle.
Fit the other end tightly onto the bleeder valve.
Place the tubing’s free end into a disposal bottle to catch old fluid.
Pump the Mityvac handle to create 10–15 inHg of vacuum.
While holding vacuum, open the bleeder valve (¼ to ½ turn) with a wrench.
Watch for air bubbles in the tubing and old fluid draining out.
Keep the master cylinder topped off to avoid introducing more air.
Continue until no air bubbles are seen and only clean fluid flows.
Close the bleeder valve before releasing vacuum to prevent air backflow.
Follow the correct bleeding sequence (usually farthest to nearest from the master cylinder):
Rear Passenger → Rear Driver → Front Passenger → Front Driver (varies by vehicle).
Press the brake pedal to check for firmness.
If spongy, repeat bleeding or check for leaks.
| Issue | Solution |
|---|---|
| No fluid flow | Check for clogged bleeder valve or low vacuum. |
| Air keeps entering | Tighten connections, check master cylinder level. |
| Weak vacuum seal | Use thread tape on bleeder valve or replace tubing. |
✔ One-person operation (no pedal pumping needed).
✔ Visual confirmation of air bubbles via clear tubing.
✔ Faster & cleaner vs. traditional methods.
Always use fresh, sealed brake fluid (hygroscopic—absorbs moisture from air).
If problems persist, inspect for leaks in wheel cylinders or lines.