The 1999 AM General Hummer has 3 NHTSA recall campaigns affecting an estimated 4,005 vehicles. Recall repairs are always free at any authorized dealer. Owners have filed 2 complaints with NHTSA, most often about the engine and engine cooling. Last updated July 5, 2026.
VEHICLE DESCRIPTION: SPORT UTILITY VEHICLES. THE TURN SIGNAL SWITCH PLASTIC CANCELLATION PIN CAN WEAR PREMATURELY CAUSING THE SIGNALS TO FAIL TO CANCEL AFTER COMPLETING A TURN.
Consequence
THIS COULD SEND AN INCORRECT LAMP SIGNAL TO OTHER VEHICLES, INCREASING THE RISK OF A CRASH.
Remedy
DEALERS WILL REPLACE THE TURN SIGNAL SWITCH WITH A NEW SWITCH HAVING A METAL CANCELLATION PIN. OWNER NOTIFICATION BEGAN NOVEMBER 16, 2001. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT AM GENERAL AT…
SERVICE BRAKES, HYDRAULIC00V0050002000-01-11980 affected
Defect
VEHICLE DESCRIPTION: A POTENTIAL CHAFING CONDITION OCCURS BETWEEN THE FLEXIBLE BRAKE LINES WHICH CONNECT THE MASTER CYLINDER TO THE ABS MODULATOR. THIS CONDITION CAN LEAD TO ONE OR BOTH OF THE BRAKE LINES DEVELOPING A BRAKE FLUID LEAK.
Consequence
A BRAKE FLUID LEAK CAB CAUSE A REDUCTION IN BRAKE LINE PRESSURE AND RESULTING IN LONGER-THAN-NORMAL STOPPING DISTANCES.
Remedy
DEALERS WILL REPLACE THE MASTER CYLINDER TO ABS MODULATOR LINES.
SERVICE BRAKES, HYDRAULIC99V0590001999-03-23186 affected
Defect
VEHICLE DESCRIPTION: SPORT UTILITY VEHICLES. THE NUTS USED TO ATTACH THE MASTER CYLINDER TO THE HYDROBOOST BOLTS WERE OF THE METRIC TYPE RATHER THAN THE REQUIRED ENGLISH TYPE.
Consequence
A LOOSE MASTER CYLINDER CONDITION CAN OCCUR, CAUSING LONGER THAN NORMAL BRAKE PEDAL TRAVEL DURING BRAKE PEDAL APPLICATIONS.
Remedy
DEALERS WILL REPLACE THE MASTER CYLINDER-TO-HYDROBOOST MOUNTING BOLTS AND NUTS.
Complaints by component
ENGINE AND ENGINE COOLING:ENGINE
1
SEATS:FRONT ASSEMBLY:HEAD RESTRAINT
1
Total complaints2
What owners report
Verbatim reports filed with NHTSA, lightly edited for readability and with personal
information removed.
“The u.s. Army has recently made it mandatory for all soldiers driving in hummv's (and other tactical vehicles) to wear the kevlar helmets, even on public highways. Most of these vehicles have no headrest. Requiring soldiers to add the weight of the helmet (3.1 to 4.2 pounds) to their cranium will…”
“Cylinder wall number 8 cracked leaving the engine useless. *ph consumer made an investigation about the defect of the vehicle and found out that general motors (gm) knew about the problem on the engine block. Up to this date gm refused to offer any assistance on the replacement of the engine.…”
Recall, complaint, and investigation records from official NHTSA datasets (FLAT_RCL,
FLAT_CMPL, FLAT_INV), synced weekly. Counts reflect NHTSA records for the 1999 AM General Hummer as of
July 5, 2026. Complaint narratives are consumer-submitted and unverified. This page
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