Total Complaints
721 filings
GMC SIERRA · model year
721 NHTSA complaints, 58 crash reports for this specific cohort.
NHTSA overall rating
Not crash-tested
New Car Assessment Program
The 1999GMCSIERRA carries 721 consumer safety complaints in NHTSA's Office of Defects Investigation database for this specific model-year cohort. Within that volume, owners reported 58 crashes, 2 fires, 36 injuries, and 1 fatality. No NCAP 5-star crash-test rating is available for this model year in the federal database.
Component-level analysis is where model-year complaints become actionable: the top complaint category for the 1999 SIERRA is service brakes, hydraulic:antilock/traction control/electronic limited slip with 197 filings, followed by service brakes, hydraulic:antilock/traction control/electronic limited slip:control unit/module (33) and service brakes, hydraulic (29). Concentration in one or two component groups is the classic signature of a systemic defect; a flat distribution usually reflects normal aging, warranty complaints, or isolated build-plant variability.
NHTSA currently has 2 investigation files overlapping the 1999 SIERRA. Owners comparing this cohort against neighboring years should pair the counters above with the complaint-by-year trend on the parent model page — a spike in a single year often tracks to a platform refresh, a new transmission supplier, or an updated ECU calibration. Use the related-complaint feed below to read raw owner narratives before deciding whether any pattern here affects your specific use case.
Total Complaints
721 filings
Crashes Reported
58 reports
Source
NHTSA ODI
Federal complaints database
Above median complaint volume — review patterns below.
| Component | Count |
|---|---|
| SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP | 197 |
| SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP:CONTROL UNIT/MODULE | 33 |
| SERVICE BRAKES, HYDRAULIC | 29 |
| SERVICE BRAKES | 25 |
| STRUCTURE:BODY:TAILGATE:HINGE AND ATTACHMENTS | 21 |
| SEATS | 20 |
| TIRES | 20 |
| VEHICLE SPEED CONTROL:ACCELERATOR PEDAL | 20 |
| POWER TRAIN:AUTOMATIC TRANSMISSION | 19 |
| VEHICLE SPEED CONTROL | 16 |
| SERVICE BRAKES, AIR:ANTILOCK:CONTROL UNIT/MODULE | 16 |
| SUSPENSION:FRONT | 14 |
| SUSPENSION | 13 |
| TIRES:TREAD/BELT | 11 |
| AIR BAGS:FRONTAL | 10 |
WHILE PULLING OUT OF MY DRIVEWAY I EXPERIENCED COMPLETE BRAKE FAILURE. LOOKED UNDER TRUCK AND BRAKE FLUID WAS EVERYWHERE AND THE BRAKE LINES WERE SEVERELY RUSTED AND HAD BUSTED. LOOKED IT UP AND THIS APPEARS TO BE A COMMON PROBLEM WITH THIS MODEL TRUCK BUT THERE HAS NEVER BEEN A RECALL?! THIS ISSUE NEEDS TO BE ADDRESSED WITH GM.
Mileage: 190,000
I WAS DRIVING AND WENT TO APPLY BRAKES FOR THE STOP SIGN AHEAD, AND I HAD NO BRAKES. ONCE I HAD THE TRUCK HOME I PARKED IT. I DETERMINED THAT THE BRAKE LINES HAD RUSTED THROUGH BY HAVING A PIECE OF CARDBOARD UNDER THE TRUCK TO LOCATE THE LEAKING BRAKE FLUID. I'M SO LUCKY THAT I DIDN'T HAVE A CAMPER ON THE TRUCK AND HAD GONE ON VACATION TO COLORADO, AS I INTENDED THIS TO BE MY RECREATIONAL VEHICLE FOR THIS PURPOSE. I AM HAUNTED BY THE POSSIBLE SCENARIOS AND CRASHES THAT COULD HAVE OCCURRED TO ME AND MY FAMILY. WIFE, SON, AND TWO DAUGHTERS. THIS NEEDS TO BE ADDRESSED BEFORE OTHER HUMAN BEINGS END UP SERIOUSLY INJURED, TRAUMATIZED, OR DEATH BEING VERY HIGHLY LIKELY. SO I HAVE A NEAR NEW TRUCK SITTING IN THE YARD FOR NEARLY THE PAST FIVE YEARS. MY ATTEMPT TO INSTALL AFTER-MARKET BRAKE LINES HAS BEEN A FAILURE. GM SHOULD BE RESPONSIBLE FOR THIS CATASTROPHIC FAILURE. I KNOW AS TIME GOES BY OTHER BRAKE LINES ON THESE MODELS WILL RUST AND FAIL. I WILL BE HERE AS A WITNESS, AND SO WILL THE TRU
Mileage: 58,000
DRIVING DOWN HILL, APPROX SPEED OF 45 MPH, WENT TO APPLY BRAKES WHEN DID HEARD POP NOISE AND BRAKE PEDAL WENT TO THE FLOOR WITH NO STOPPING. PUMPED ON BRAKES AND GEARED DOWN TRUCK TO SLOW DOWN. PULLED OVER TO SIDE OF ROAD TO NOTICE THAT FLUID WAS COMING OUT OF THE BODY. WAS ABLE TO GET MIRROR AND RESEARCH AND FIND THE BRAKE LINE HAD CORRODED WITH RUST, AND IT HAS SPLIT. *TR
Mileage: 81,000
TL* THE CONTACT OWNS A 1999 GMC SIERRA. THE CONTACT STATED THAT WHILE DRIVING 25 MPH, THE BRAKES FAILED. AS A RESULT, THE CONTACT HAD TO SWITCH GEARS IN ORDER TO STOP THE VEHICLE. AFTER INSPECTING THE VEHICLE, THE CONTACT NOTICED THAT THE BRAKE LINE HAD FRACTURED. THE VEHICLE WAS NOT DIAGNOSED OR REPAIRED. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS 196,000.
Mileage: 196,000
I WAS COMING TO A STOP AND I LOST MY BRAKES I WAS ABLE TO GET IT STOPPED. TOOK IT TO MY MECHANIC RIGHT AWAY AND WAS TOLD THE BRAKE LINE BURST AND HIT MY GAS LINE BUSTING IT AS WELL. THEY HAD THE VEHICLE FOR OVER 3 WEEKS. THEY REPAIRED THE GAS LINE EASY ENOUGH BUT THE BRAKE LINE HAD TO BE COMPLETELY REPLACED. *TR
Mileage: 172,656
I WAS COMING TO A STOP AND I LOST MY BRAKES I WAS ABLE TO GET IT STOPPED. TOOK IT TO MY MECHANIC RIGHT AWAY AND WAS TOLD THE BRAKE LINE BURST AND HIT MY GAS LINE BUSTING IT AS WELL. THEY HAD THE VEHICLE FOR OVER 3 WEEKS. THEY REPAIRED THE GAS LINE EASY ENOUGH BUT THE BRAKE LINE HAD TO BE COMPLETELY REPLACED. *TR
Mileage: 172,656
DURING MANY OCCASIONS SINCE I PURCHASED THE TRUCK(NEW) ,THE ABS SYSTEM WOULD ACTIVATE AS I AM APPLYING THE BRAKES AND THE TRUCK IS ALMOST STOPPED: LOUD SHUDDER,THE TRUCK WOULD KEEP ROLLING EVEN AFTER PRESSING HARD ON THE BRAKE PEDAL(AT WALKING SPEED);IT HAS BEEN A RATHER SCARY EXPERIENCE ALL ALONG AS MORE THAN ONCE ,I CAME CLOSE TO HIT OTHER VEHICLES AND MY GARAGE DOOR AND BACK WALL. *TR
Mileage: 30,000
THIS IS THE CONTINUING STORY OF THE UNSAFE BRAKING SYSTEM ON MY 1999 GMC TRUCK. ON 7/15/14 AS I WENT TO STOP AT A RED LIGHT MY BRAKE PEDAL BEGAN TO SLOW THE TRUCK AND THEN THE PEDAL TRAVEL ALMOST TO THE FLOOR, THE RED WARNING LIGHT CAME ON AND I HAD TO USE THE EMERGENCY BRAKE TO STOP. I WAS VERY CLOSE TO HOME AND MANAGED TO SLOWLY MAKE IT SAFELY BACK WHERE I DISCOVERED, FOR THE THIRD TIME, THAT MY BRAKE LINE HAD RUSTED THROUGH. I HAD LOST A PINT OF FLUID AND LATER FOUND THE LEAKING BRAKE LINE. THIS WILL BE THE THIRD TIME I HAVE HAD TO CHANGE THE RUSTY BRAKE LINES ON MY TRUCK. I REALIZE MY VEHICLE IS OLD, BUT THIS HAS BEEN A RECURRING PROBLEM FOR AT LEAST TEN YEARS. MY 1976 PONTIAC FIREBIRD STILL HAS IT'S ORIGINAL BRAKE LINES THAT SHOW NO SIGNS OF RUST. MY GMC BRAKE LINES ARE COMPLETELY RUSTED. I HAVE SPENT MORE THAN $5000 ON REPAIRING THE BRAKES ON THIS VEHICLE SINCE PURCHASING IT NEW IN 1999. I HAVE HAD MORE THAN FIVE VERY CLOSE CLOSE CALLS WITH ASSORTED BRAKE FAILURES WITH THE RUSTY
Mileage: 81,000
THE BRAKE LINES IN MY 1999 GMC SIERRA BLEW OUT, AND I WAS BARELY ABLE TO STOP THE TRUCK BEFORE ENTERING A BUSY HIGHWAY FROM MY DRIVEWAY - THE BRAKE PEDAL WENT ALL THE WAY TO THE FLOOR, PROVIDING VERY LITTLE BREAKING POWER AND TAKING A MUCH LONGER TIME TO STOP AND A MUCH LONGER DISTANCE TO STOP THAN NORMAL . I WAS INFORMED THAT MY BRAKE LINES HAD COMPLETELY RUSTED OUT, NEEDING FULL REPLACEMENT, WHICH I HAD DONE LAST WEEK AT CONSIDERABLE EXPENSE. IT IS UNCONSCIONABLE THAT GM KNEW ABOUT THIS PROBLEM AND FAILED TO INFORM OWNERS OF THEIR VEHICLES TO HAVE THEIR BRAKE LINES INSPECTED! I HAVE OWNED THIS TRUCK SINCE IT WAS NEW, AND MY ADDRESS HAS NOT CHANGED SINCE IT WAS PURCHASED, SO MY ADDRESS IS IN THEIR FILES. *JS
Mileage: 151,704
WHILE DRIVING MY VEHICLE I WAS STOPPING AND THE BRAKES WERE SHOT. I HAD TO PUSH THE PEDAL AS HARD AS POSSIBLE TO THE FLOOR TO GET IT TO STOP. LUCKILY I NARROWLY AVOIDED AN ACCIDENT WITH THE PERSON IN FRONT OF ME. I TOOK THE TRUCK TO GET LOOKED AT AND THE BRAKE LINES ARE LEAKING FROM THE MASTER CYLINDER TO THE ABS UNIT. THEY ARE EXTREMELY RUSTED AND THEY NEED TO BE REPLACED. THE ESTIMATE WAS OVER $1000. *TR
Mileage: 156,000
BRAKE FLUID LEAKING ALL OVER BOTTOM OF TRUCK SPRAYING OUT I TOOK TO A MECHANIC AND HAD 1000 DOLLAR BRAKE LINE JOB DONE GOT TRUCK BACK AND ABS BRAKES WORKED LIKE MANUAL BRAKES HAD A SENSOR AND 2 BALL JOINTS REPLACED IM BEING RIPPED OF FROM A GMC LOYAL CUSTOMER I WAS I GUESS BACK TO FORD OR TOYOTA FOR MY NEXT NEW TRUCKS I HAD WARRANTY ISSUES YOU CHEAP [XXX] WOULDNT PAY FOR A WATERPUMP THAT WAS LEAKING ONLY A 7 DOLLAR GASKET ALSO HAD A TRANSMISSION ON MY WORK VAN REPAIR AND THEN REPLACED AFTER A MONTH OF RUN AROUND. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *TR
Mileage: 150,145
BRAKE FLUID LEAKING ALL OVER BOTTOM OF TRUCK SPRAYING OUT I TOOK TO A MECHANIC AND HAD 1000 DOLLAR BRAKE LINE JOB DONE GOT TRUCK BACK AND ABS BRAKES WORKED LIKE MANUAL BRAKES HAD A SENSOR AND 2 BALL JOINTS REPLACED IM BEING RIPPED OF FROM A GMC LOYAL CUSTOMER I WAS I GUESS BACK TO FORD OR TOYOTA FOR MY NEXT NEW TRUCKS I HAD WARRANTY ISSUES YOU CHEAP [XXX] WOULDNT PAY FOR A WATERPUMP THAT WAS LEAKING ONLY A 7 DOLLAR GASKET ALSO HAD A TRANSMISSION ON MY WORK VAN REPAIR AND THEN REPLACED AFTER A MONTH OF RUN AROUND. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *TR
Mileage: 150,145
BRAKE FLUID LEAKING ALL OVER BOTTOM OF TRUCK SPRAYING OUT I TOOK TO A MECHANIC AND HAD 1000 DOLLAR BRAKE LINE JOB DONE GOT TRUCK BACK AND ABS BRAKES WORKED LIKE MANUAL BRAKES HAD A SENSOR AND 2 BALL JOINTS REPLACED IM BEING RIPPED OF FROM A GMC LOYAL CUSTOMER I WAS I GUESS BACK TO FORD OR TOYOTA FOR MY NEXT NEW TRUCKS I HAD WARRANTY ISSUES YOU CHEAP [XXX] WOULDNT PAY FOR A WATERPUMP THAT WAS LEAKING ONLY A 7 DOLLAR GASKET ALSO HAD A TRANSMISSION ON MY WORK VAN REPAIR AND THEN REPLACED AFTER A MONTH OF RUN AROUND. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *TR
Mileage: 150,145
BRAKE FLUID LEAKING ALL OVER BOTTOM OF TRUCK SPRAYING OUT I TOOK TO A MECHANIC AND HAD 1000 DOLLAR BRAKE LINE JOB DONE GOT TRUCK BACK AND ABS BRAKES WORKED LIKE MANUAL BRAKES HAD A SENSOR AND 2 BALL JOINTS REPLACED IM BEING RIPPED OF FROM A GMC LOYAL CUSTOMER I WAS I GUESS BACK TO FORD OR TOYOTA FOR MY NEXT NEW TRUCKS I HAD WARRANTY ISSUES YOU CHEAP [XXX] WOULDNT PAY FOR A WATERPUMP THAT WAS LEAKING ONLY A 7 DOLLAR GASKET ALSO HAD A TRANSMISSION ON MY WORK VAN REPAIR AND THEN REPLACED AFTER A MONTH OF RUN AROUND. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *TR
Mileage: 150,145
BRAKE FLUID LEAKING ALL OVER BOTTOM OF TRUCK SPRAYING OUT I TOOK TO A MECHANIC AND HAD 1000 DOLLAR BRAKE LINE JOB DONE GOT TRUCK BACK AND ABS BRAKES WORKED LIKE MANUAL BRAKES HAD A SENSOR AND 2 BALL JOINTS REPLACED IM BEING RIPPED OF FROM A GMC LOYAL CUSTOMER I WAS I GUESS BACK TO FORD OR TOYOTA FOR MY NEXT NEW TRUCKS I HAD WARRANTY ISSUES YOU CHEAP [XXX] WOULDNT PAY FOR A WATERPUMP THAT WAS LEAKING ONLY A 7 DOLLAR GASKET ALSO HAD A TRANSMISSION ON MY WORK VAN REPAIR AND THEN REPLACED AFTER A MONTH OF RUN AROUND. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *TR
Mileage: 150,145
COMING BACK FROM THE STORE THEN ENTERING MY DRIVE WAY THE BRAKE PEDAL WENT TO FLOOR. USED EMERGENCY BRAKE TO STOP. LOOKED UNDER TRUCK AND SAW BRAKE FLUID ON GROUND.HAD TO BE TOWED IN. HAD TO HAVE BRAKE LINES REPLACE. HEAVY CORROSION . TRUCK HAD BAD RUST PROBLEM. COST,$883.00AT 60,000 MI GAS LINES STARTED TO LEAK FROM CORROSION. HAD TO BE REPLACED ON 10/09/2013. FOR $900.00THE UNDER CARRIAGE IS BADLY RUSTED AND LOOKS IT HAS 200,000MI INSTEAD OF 60,000MI. BRAKE BACKING PLATES ARE ALMOST RUSTED AWAY. HAD TO REPLACE REAR CALIPERS ,ROTORS,PADS 2 TIMES. *TR
Mileage: 50,900
TL* THE CONTACT OWNS A 1999 GMC SIERRA. THE CONTACT STATED THAT WHILE DRIVING VARIOUS SPEEDS, HE SMELLED A STRONG GASOLINE ODOR INSIDE OF THE VEHICLE. THERE WAS ALSO FUEL VISIBLE ON THE GROUND. THE CONTACT INSPECTED THE VEHICLE AND NOTICED THAT BOTH THE FUEL AND BRAKE LINES WERE COMPLETELY RUSTED. THE VEHICLE WAS NOT DIAGNOSED OR REPAIRED. THE MANUFACTURER WAS NOT NOTIFIED OF THE PROBLEM. THE APPROXIMATE FAILURE MILEAGE WAS 71,000.
Mileage: 71,000
TL* THE CONTACT OWNS A 1999 GMC SIERRA. THE CONTACT STATED THAT WHILE DRIVING VARIOUS SPEEDS, HE SMELLED A STRONG GASOLINE ODOR INSIDE OF THE VEHICLE. THERE WAS ALSO FUEL VISIBLE ON THE GROUND. THE CONTACT INSPECTED THE VEHICLE AND NOTICED THAT BOTH THE FUEL AND BRAKE LINES WERE COMPLETELY RUSTED. THE VEHICLE WAS NOT DIAGNOSED OR REPAIRED. THE MANUFACTURER WAS NOT NOTIFIED OF THE PROBLEM. THE APPROXIMATE FAILURE MILEAGE WAS 71,000.
Mileage: 71,000
PIRELLI SCORPION TIRES, SIZE P255/70R16, BOUGHT 7/11/2007 FROM TIRERACK.COM. AT 21,000 MILES, TIRES ARE SHOWING SEVERE WEATHER CRACKING, VERY SIMILAR TO WHAT I EXPERIENCED WITH MY FORD EXPLORER DURING THE FIRESTONE TIRE RECALL IN 2000. TIRE RACKS WARRANTY SPECIFICALLY STATES TIRES WITH WEATHER CRACKING WHICH WERE PURCHASED MORE THAN 4 YEARS PRIOR TO PRESENTATION FOR ADJUSTMENT ARE NOT COVERED BY THE WARRANTY. ALTHOUGH THERE IS AMPLE TREAD LIFE LEFT, THESE TIRES ARE SIMPLY NO LONGER SAFE. *TR
Mileage: 64,000
PIRELLI SCORPION TIRES, SIZE P255/70R16, BOUGHT 7/11/2007 FROM TIRERACK.COM. AT 21,000 MILES, TIRES ARE SHOWING SEVERE WEATHER CRACKING, VERY SIMILAR TO WHAT I EXPERIENCED WITH MY FORD EXPLORER DURING THE FIRESTONE TIRE RECALL IN 2000. TIRE RACKS WARRANTY SPECIFICALLY STATES TIRES WITH WEATHER CRACKING WHICH WERE PURCHASED MORE THAN 4 YEARS PRIOR TO PRESENTATION FOR ADJUSTMENT ARE NOT COVERED BY THE WARRANTY. ALTHOUGH THERE IS AMPLE TREAD LIFE LEFT, THESE TIRES ARE SIMPLY NO LONGER SAFE. *TR
Mileage: 64,000
Data as of 2025. Sources: NHTSA Office of Defects Investigation (ODI) complaints database, NHTSA recall campaign API, NHTSA NCAP crash-test ratings, and NHTSA FARS for fatality cross-reference.
Read our methodology — how this data is sourced, computed, and verified.