Why is the brake pedal on my 1990-1993 Chrysler Imperial suddenly hard?

Short answer: A very hard brake pedal on a 1990-1993 Imperial usually means the Bendix-10 anti-lock unit's electric pump has quit. That pump supplies brake power assist, so when it stops the car takes a lot of leg force to stop. NHTSA recall 96V099000 covers wear in this unit. Check your VIN, but parts for these cars are now hard to find.

Symptom: The brake pedal becomes rock hard and the car is hard to stop, often with the ABS or brake light on.

What to check first

1. Look at the ABS and red brake warning lights.
2. Check the brake fluid level in the reservoir on the ABS unit.
3. Listen for the ABS pump running when you turn the key on. Silence may mean a dead pump or relay.
4. Run your VIN at nhtsa.gov/recalls for 96V099000 and 91V191000.
5. Look for wet fluid at the ABS high-pressure hose.

Likely causes

1. ABS hydraulic pump and motor failure. These cars use a Bendix-10 anti-lock system that makes its own brake boost with an electric pump instead of the usual engine vacuum booster. If the pump stops, there's no power assist and the pedal turns very hard.
2. Worn actuator piston seal in the ABS unit (recall). NHTSA recall 96V099000 says piston seal wear in the ABS control unit can wear out the pump motor.
3. Leaking ABS high-pressure hose. An earlier recall covered a high-pressure ABS hose that could leak or come loose at its crimped end on 1990-1991 cars.
4. Pedal pushrod not adjusted after repair. The rod between the booster and the pedal can be turned to change its length. If it's moved during work, the pedal may not line up.

What it usually costs

Owners did not post prices. One mechanic searched for months for ABS parts, so the cost depends on finding a used or rebuilt unit.

Is it safe to keep driving?

No. A hard brake pedal means much longer stopping distances. Don't drive it until the brakes are fixed.

DIY or shop?

Checking fluid and lights is DIY. The Bendix-10 unit is a high-pressure system and should be handled by a shop.

Recalls, bulletins and complaints in plain words

• Related recalls: NHTSA lists these recalls touching this area of the Chrysler Imperial: 91V191000 (1990-1991 model years, service brakes, hydraulic:foundation components:hoses, lines/piping, and fittings); 96V099000 (1990-1993 model years, service brakes, hydraulic:antilock/traction control/electronic limited slip). Check your VIN at nhtsa.gov/recalls. If your car is part of this recall, the dealer fixes it for free.
• Plain words: The complaint count below shows how often owners reported problems that mention these words to NHTSA. A count is not proof of a defect.
• NHTSA complaints: 83 keyword-matched complaints for Chrysler Imperial 1990–1993 (of 285 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-29; keywords: anti lock, antilock, abs, hard pedal, brake pedal, pump motor). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In '91 Chrysler Imperial ABS on Car Talk, a 1991 Imperial's brakes stopped working well and the mechanic said the whole ABS unit needed replacing, but no parts could be found. Members explained that this Bendix-10 system uses hydraulic pressure instead of a vacuum booster, so a dead pump makes the pedal very hard. They pointed to the recall covering the actuator piston and pump motor.
• In 1993 Chrysler Imperial on Car Talk, a 1993 Imperial owner took apart the brake pedal assembly and then learned the car had a recall. Members explained the pushrod comes from the booster and can be turned to change its length, and warned that getting recall work on a 20-year-old car may be hard.

Quick tip

On these Bendix-10 cars the ABS unit is also the power brake booster, so you can't just ignore the ABS light like on most cars.

Vehicle focus: Chrysler Imperial, 1990-1993 (also related to the Fifth Avenue and New Yorker of those years).

Safety / mechanic note

Brakes are a safety item. Verify with a mechanic.