SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSGMC1999FORWARD CONTROL 5.7 R, AUTOMATICREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 4 (POWER BRAKE BOOSTER - HYDRO-BOOST)TESTINGBOOSTER FUNCTIONAL TEST
1999 GMC Forward Control 5.7 R, Automatic

Booster Functional Test

1999 GMC Forward Control 5.7 R, AutomaticSECTION Booster Functional Test
WARNING: This page does not describe the selected car, but rather 35 other vehicles, including the 1999 GMC Yukon, 1999 GMC Suburban, 1999 GMC Sierra, 1999 GMC Savana Special, and 1999 GMC Savana Camper Special. However, it is still accessible from the selected car via links, so may be relevant.

With engine off, press brake pedal several times to deplete accumulator reserve. Press and hold brake pedal with about 40 lbs. (18 kg) pressure. Start engine. Brake pedal should fall slightly, then push back against foot. If no action is felt, booster is not operating properly.

RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

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

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote 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.