Out of nowhere one day my brakes started doing something weird. As I would press lightly on the brakes coming to a slow stop, sometimes the pedal would suddenly get very stiff, I would hear a groaning sound, and the truck would not want to stop. Instinct then says "press the pedal harder", which I did and the truck then stops. I then pump the brakes a few times before moving again to ensure the pedal returns to normal, and the issue goes away like nothing ever happened. The brakes would feel and function fine. Of course, until I got this same symptom again. It's difficult to pinpoint the location of the groaning sound while driving. This doesn't happen every time I try to stop. It's very intermittent and random, and it has never happened when I've hit the brakes hard - but it still happens from time to time.

Last week I started smelling burning brake pads and noticed the drivers side rear brakes were heating up a lot, also intermittently. It wasn't getting very hot every time I drove, but once in a while it would get so hot I could actually see them smoking. I figured the caliper was locking up. I thought this may have been the source of my weird brake pedal problem. So I changed both rear calipers correctly (after installing them bleeders down first like a moron) and bled all four calipers. I finished the job today and when taking it for a test drive, slowly stopping normally, and then testing the brakes harder, they seemed to work fine.

Then that weird symptom happened again, and it continues to happen randomly. What's goin on here? Is one of my front calipers acting up too? Or is this a master cylinder issue? I'm kinda stumped. Thanks for any advice.

 

Sounds like a brake booster/master cylinder issue to me....just went through this same thing on my girlfriend's car. She didnt have the noise or the heating issue, but her pedal would intermittently be really hard to push and she would have no brakes. It almost always did it when the car was first started in the mornings when its cold out...after she would pump the pedal a few times it would pop loose and then the brakes would be fine until the car sat for a period of time again. I replaced the booster and bled all the lines and it's been fine ever since.

 

2 or 4 wheel ABS?

 

Here's the build sheet.

S9 Deluxe Cloth 40/20/40 Bench Seat
-AZ Agate
ADJ Heavy Duty Service Group
AHC Trailer Tow Group
AHD Heavy Duty Snow Plow Prep Group
APAS Monotone Paint
A06P #6 Engineering Development Zone
BAZP 136 Amp Alternator
BCQP 750 Amp Maintenance Free Battery
BRTS Anti-Lock 4-Wheel Disc Brakes
CBEP 40/20/40 Split Bench Seat
CGDS Front Height Adjust Shoulder Belts
CGWS Next Generation Front Air Bags**
CGZS Passenger Air Bag On/Off Switch
CKJS Black Vinyl Floor Covering
CSPS Passenger Assist Handle
CUVS Behind Seat Modular Storage System
CUYS Storage Tray
DBBC All Manual Transmissions
DDP 5-Speed Manual Transmission
DHGP Shift-on-the-Fly,241HD Transfer Case
DJFS Dana M60/248MM Front Axle
DMDP 3.55 Rear Axle Ratio
DRDP 200MM Rear Axle
EAAC All Engines
EAGC All Gas Engine
EML 5.9L V8 MPI Engine
GACS Tinted Glass Windows
GFD Rear Sliding Window
GNAS Rear View Day/Night Mirror
GPUS Manual 6 x 9 Black Mirrors
GVAC All Vehicles W/O Power Mirrors
HAA Air Conditioning
HGAS Hood Insulation
HGBS Dash Liner Insulation
I63S Route 63 - CSX, Twin Oaks, PA
JAYS Instrument Cluster w/Tach
JCBS 120 MPH Primary Speedometer
JHAS Var Intermittent Windshield Wipers
JJAS Cigar Lighter
JJBS Dual Note Electric Horns
JJJS 12V Auxiliary Power Outlet
KRXS BLACK - BADGE - 4 x 4, LIFTGATE
KTXS BLACK - BADGE - DODGE, TAILGATE
LDAS Underhood Lamp
LMAS Halogen Headlamps
LNC Clearance Lamps
LPES Cargo Lamp
MBFS Bright Rear Bumper
MCTS Bright Front Bumper
MFDS Bright Grille
MHAS Black Windshield Moldings
MWDS Removable Tailgate w/Caliper Latches
NAA Federal Emissions
NBKP EVAP Control System
NFVS 35 Gallon Fuel Tank
NMCP Heavy Duty Engine Cooling
PSBA Bright Silver Metallic Clear Coat
QSBS Bright Silver Metallic Clear Coat
RAAC All Radio Equipped Vehicles
RASS AM/FM Cassette Radio
RCDP 4 Speakers
RDDP Fixed Long Mast Antenna
SBAS Variable Assist Power Steering
SCBS 2-Spoke Steering Wheel
SFBS Front Heavy Duty Shock Absorbers
SGBS Rear Heavy Duty Shock Absorbers
SHAS Front Stabilizer Bar
TBBS Full Size Spare Tire
TBMP Tire Carrier Winch
TYDS LT245/75R16E BSW All Season Tires
TZHP Michelin Brand Tires
WDVS 16X7.5 Steel 8 Lug Wheels
WLBP Steel Spare Wheel
WLYC All Steel Wheels
WMCP Bright Wheel Trim Rings
WMJP Center Hub
XBSS Pickup Box
XCMS Vendor Painted Cargo Box
XEFP Transfer Case Skid Plate Shield
XFHP Class IV Receiver Hitch
XFKP 7 Pin Wiring Harness
XFLP 7 to 4 Pin Wiring Adaptor
YAAS Build To U.S. Mkt. Specifications


Looks like 4 wheel.

 

Given that info, my first guess would be your truck is doing the ABS "happy dance". Now, whether it had any reason to do so or not, is another question. May have a flaky wheel speed sensor. Trouble is, figuring out which one. Need to see what data they are handing out, when the problem presents itself.

 

So it should throw relevant codes if I hook it up to a scan tool?

 

Nope. If the ABS lite is on, you may get a code. Otherwise, the system hasn't figgered out there is a flaky sensor yet. (if there is one.)

Typical code scanner won't read abs codes either. Need something a little meaner.

 

Crap. I've got No ABS lights, no check engine lights... nothing.

 

The scanners they have at advance auto for people to borrow will in fact read abs codes as well as obdII codes. Just an fyi...

 

Wonder if they will read live data from the wheel speed sensors.....