About an hour ago some idiot pulled out in front of me suddenly and I had to slam on the brakes. It's hard to explain but I felt something strange in the brake pedal. I drove around for a little bit and since then it's been extra "mushy". And the brake light came on. To come to a complete stop I have to literally push the pedal to the floor. When I sit at a red light it feels like it's ready to start rolling forward at any second. Like it's barely hanging on. I just had my brakes done about 6 months ago too. What the heck happened here? Thanks

 

sounds like you possibly either toasted the master, pin hole in a line, bad hose along those lines

BUT look over that entire brake system with a fine tooth comb

 

What do you mean by the master?

 

master cylinder

 

Sounds like a fluid leak somewhere. Park it and push the pedal to the floor and back about 10 times. Then look under each wheel and in the engine compartment near the master cylinder and check for leaks. If its a line or at the calipers, you will know by the puddle under the truck...

 

Check the inside of the rims also. A leaky caliper can coat the rim from fluid slinging off of it.

 

Hard to diagnose without eyes on itl but I think your dual master cylinder failed & Your brakes are now operating on one side of the master cylinder. There is a possiibility that you blew a brake line, and that would cause the system to loose hyd fluid and feel spongy


the master cylinder is a foot operated hydraulic pump that sends pressurized brake fluid through the brake lines and into the brake calipers/wheel cylinders.

In it's simplest form, the master cylinder consists of a housing, reservoir, piston, rubber cup, return spring and a rubber boot (manual only). A cylinder bore is machined into the center of the housing. The spring, cup and piston(s) slide in this bore and produce hydraulic pressure. The reservoir keeps the system full of fluid as the brake lining wears and the dust boot serves to keep contaminates from entering the rear of the master cylinder.

The dual master cylinder is required on all vehicles manufactured since 1967.
Dual master cylinders have two separate chambers that separate the front and rear brake circuits. This type of system prevents the total loss of

braking action in the event of brake fluid loss. The brake circuits can be


split front and back or diagonally. Both styles will stop the vehicle with only one circuit operating, but it is not safe for normal use.

Operation of the master cylinder is simple. When the brake pedal is depressed, force is applied through the push rod to the master cylinder piston. As the piston cup is forced forward, brake fluid is trapped and hydraulic pressure builds. Hydraulic pressure causes the movement of brake assemblies, such as calipers or wheel cylinders, to stop the rotation of the wheels. When the brake pedal is released, fluid is forced back through the lines into the master cylinder reservoir.

The most common cause of master cylinder failure can be attributed to:

• Contamination - brake fluid is hygroscopic (attracts water)
• Normal Wear
• External corrosion

 

Take it to where you had your brakes done just in case it's something they'll warranty. Sounds like something blew though. Like stated, I'd guess either the master cylinder or a caliper. Lines take a beating, I've never heard of one blowing from a hard stop. (And I do brakes at work)

 

Great information guys, thanks. I had my guy come to the house to check it out and it was the master cylinder. How does $160 sound for getting it fixed? Is that fair?

 

that's not bad