Hi, I recently had both wheel bearings replaced on the vehicle listed above,the next day my brake light came on, the 2nd day after I started losing brake pressure, and now I think that I am losing fluid. I parked it right away. my question is wwhen the shop replaced the bearings would they have possibly had to remove anything to do with the brake lines up front? or perhaps they damaged them?

The most common reasons are listed below. As you vehicle is reasonably new some of the one further down the list will be less likely but it does happen. How long after the repair did the vibration start? If it was on the same day or a few days after take it back to the repairer so they can check their work. On rare occasions even brand new parts can be faulty. It's happened to me with a front wheel bearing. 80 miles and it made more noise than the old one.
I would suggest you get the first 2 on the list checked first as these are the cheaper and simpler fixes.

Wheel and tyre not balanced,
Badly worn tyre,
Warped brake disc,
Worn wheel bearing,
Worn CV joint,
Drive shaft out of balance,
Worn suspension parts.

The computer has detected a condition that indicates a fault with the ABS/Traction system. Typically that's caused by a wheel sensor problem, but it can also be caused by a faulty connector, peripheral device or the computer.
The above is the shop or garage answear. How about telling us how to fix the problem , besides replacing the computer or wheel sensor? How do we check these things?
Sometimes can be as simple as a short circuit in the rear break lights or a faulty connection in the break lights.
You can start checking the break light system. Then the sensors and finally the computer.

Antilock Brakes

You have a wheel speed sensor that is not working correctly. The ABS computer is losing the signal from the wheel speed sensor and interprets this as a wheel locking up, so it is going into antilock mode. When it does this on dry pavement when it is obvious that there is no wheel actually locking up it is called "false Antilock Mode" or "Overactive Antilock Mode". This is a pretty common problem on several vehicles.

The system on your Blazer uses wheel speed sensors which are an integral part of the front wheel bearing and hub assembly to determine wheel speed for the front wheels. It uses the Vehicle Speed Sensor (VSS) to determine rear wheel lock-up. The VSS data is shared between the Body Control Module (BCM), the Vehicle Control Module (VCM), The Powertrain Control Module (PCM), the Transfer Case Control Module (TCCM) and the Electronic Brake Control Module (EBCM - AKA "Antilock Module").
The problem is MOST LIKELY being caused by a front wheel bearing being loose (pretty common) which will require replacement of the front wheel bearing and hub assembly. However, it can also be caused by the VSS or a breakdown in communication between any of the modules that share the VSS data.

If you have either of the front wheel bearings making noise (growling or whining) then that is almost positively the cause of your problem. However, if it cannot be determined this way, the computer network will need to be scanned to find out which it is.

Hi, I can help

You have a bad wheel bearing assembly.
The bearing is starting to seize up, and it is telling computer there is a problem in ABS system, as well as AWD system.

First thing is to locate which bearing it is in the front end of the vehicle.

1)Jack up each side of the front end, place a safety support stand or jack stand under frame of vehicle.
2)Once vehicle wheel is free from ground spin the wheel and listen for grinding.
3)Compare each wheel as you spin and make your best judgment on which is more noisy.
4)This is your problem wheel you need to remember which side of the vehicle is the source of problem when ordering the part from your local auto parts store.

To repair: Remove wheel, remove brake caliper, then brake caliper bracket, then the rotor, remove center axle nut, then remove bolts for wheel bearing hub assembly.
Your ABS and AWD lights will reset themselves upon successful test drive following repair.
Let me know if you need more assistance or pictures.
Good Luck, have a great day.

brake fluid RARELY needs flushed. i personally have never done it to any vehicle. sticking caliper sounds more like an issue than fluid or yes it could be the hub bearing causing excessive drag on that wheel

Take it back to who did the brakes,there is a brake,or brakes locking down,and holding the wheel from turning,you may need a new brake hose,or caliper.

What did you replace?If it where a sensor,make sure you changed the right sensor,also wheel bearings gone bad will cause this,also bad rotors,and brake pads.If the vehicle has problems stopping like the computer thinks ,then the light will come on,but if hitting bumps causes the light to come on,then the wheel bearing or rotor,or brake liners(pads)could be the problem.I hope this was some help.

Fuse box next to clutch pedal (brake on automatic). There is a fuse in there for the brakes. I have the same problem but my fuse is OK.

As I already knew one of my rear wheel bearings was going, ie lots of noise above 60km, vehicle has 250K KMs, I read my service manual and it indicated most probable one of the bearings reading zero under 5 KM per hr causing full pressure by the ABS to be exerted on the rear brakes. Works fine with the ABS cct breaker pulled. Solid brakes with ABS above 5 km/hr. No ABS light on, do not have an ABS code reader only the basic GM code reader. Vehicle is 1992. Thanks Anyway

Common causes for High-pitched noise from rear wheels are:

The wheel bearing: this is not usually dangerous in the short term, but I recommend contacting a mechanic and having it fixed. To test the wheel bearing, you lock front wheels, and jack up the car rear and spin the wheel (handbrake unlocked). If bearing is worn you hear a drone. When is the bearing, often car starts vibration above 40 mph.
Noise from bearing can be continuous, intermittent, only when steering, only when hot.

The brake pads: when brake pads are worn out they start making a squealing noise, in this case the noise is only when you brake or continuous. When you jack up the car the wheel may be a little stiff, but not necessarily.When brake pads are completely gone you also hear a scratching noise when braking. Inspect your brakes immediately.

Other suspension problems: Jack up the car as suggested above, check if the wheel has a slight play on the sides. Check all of the suspension components, suspension mounting points, and steering linkage for damage. Also, check the frame rail for wrinkles. It is very important that these components be in good condition, if you notice any problem here, go immediately to a mechanic.

Try doing the simple test above, reinstalling the wheel and working the tire back and forth. This is a common test for bad ball joints and wheel bearings.