What exactly would cause left front brake to grab randomly

What type of truck is this? Faulty break lines. Too much air in brake lines. Rotors. In need of pads. Leaking calliper.

This is usually a bad bearing. The tire is tilting to one side and causing uneven wear. The shimmy is because of the slack in the bearing and the contact the front rotor is having with the brake pad. Every time the low side comes around the rotor will hit the brake pad and grab it.

You will need bearings and brake work.

is this the front brakes doing this?? or the rear?? i would recomend changing pads and rotors and drums(rear) and shoes(rear)

Check front end steering linkages for any play, as well as rear brakes for sticking or grabbing as well. Not unusual for a rear brake grabbing, to cause front end to want to wander.

you have a serious problem with your brakes have fixed immediatly brakes will lock up on you possible causeing accident the light is a warning light the brakes are grabeing cause there failing

the abs light on the dash should come on when the abs is working (emergency braking)if it comes on when braking normally(gently)chances are a sensor is gone(replace in pairs,fronts & rears)
abs stops the wheels from locking up in an emergency brake situation,you will feel the grab-release,grab-release on the brake pedal......

It is not your A/C the problem, try this:
1- Apply the brake.
2-Open ignition to on position II engine off.
3-make sure to set A/C to low temp with A/C button off.
4-Start the car while keeping foot on the brake.
5-push A/C button on and make sure that a/c compressor comes on and wait around 10-12 second.
6-Let foot of the brake and wait ,check if DSC light comes on if not pump the brake several time with A/C compressor on if light comes on, if it dose mean your MASTER CYLINDER BRAKE SENSORS NEED CHANGING.
This was the solution for my car,I had exact the same problem.

Here's a link to get an owner's manual.



http://search.stores.ebay.com/Car-and-Truck-Owners-Manuals_1991-Chevy-Sprint_W0QQfciZ10QQfclZ3QQfsnZCarQ20andQ20TruckQ20OwnersQ20ManualsQQfsooZ2QQfsopZ2QQsaselZ1040964QQsofpZ0

Hi elfiallison,
By brakelight I am going to assume you mean the warning indicator on the dash. Not sure if you are planning to do the work yourself or if you are just looking to find out the probable cause. Here are some things to look at to narrow down the exact problem but you are definitely going to need at least a front wheel brake job. I would suggest that you replace the pads, calipers and rotors when doing this since the problem has gone this far.

You most likely have a leaking front caliper that is causing these problems.
Is the brake fluid low in the master cylinder?

Remove the front tires and do a visual inspectioninspection of the braking components.
1) Check for any visable leaks, a leaking caliper will cause the brakes to grab and lock up.

2) Spin the rotors, they should spin freely without grabbing, there will be a slight drag from the brakes. Both sides should be equal. Grabbing rotors can indicate a warped rotor which can also cause the brakes to lock up.

3) Is there plenty of bake pad remaining? You need to have a minimum of 1/4" pad remaining though more is prefered. Low pads can allow the piston to come out of the caliper farther than designed and not allow the piston to retract properly.

If you would like assistance on how to do these repairs just reply to this message and I will help you out.

Good Luck