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Home >> Jeep >> 1996 >> Grand Cherokee Limited, 5.2 Y >> Repair and Diagnosis >> External Pages >> Different car >> Section 203 (Disc & Drum) >> Testing >> Power Brake Unit

Power Brake Unit

WARNING: This page is about a different car, the 1994 Plymouth Sundance, 1994 Plymouth Acclaim, 1994 Dodge Spirit, 1994 Dodge Shadow, and 1994 Chrysler LeBaron. However, it is still accessible from the selected car via links, so may be relevant.
  1. Run engine for 2 minutes. Turn engine off. Press brake pedal several times with normal pressure. Pedal height should be lowest when first pressed but should gradually become higher each time pedal is pressed.
  2. With engine stopped, step on brake pedal several times to ensure pedal height does not change. Press and hold brake pedal. Start engine. Pedal should move down slightly.
  3. With engine running, press and hold brake pedal. Stop engine. Continue holding pedal down for 30 seconds. Pedal height should not change.
  4. If power brake unit does not test as specified, inspect vacuum hose. If vacuum hose is okay, replace power brake unit.
CAUTION: DO NOT remove check valve from booster. DO NOT disassemble power brake unit. Booster is serviced as complete unit only.