Aaack, No Brakes

[asilverblazer]

Terrible news for those motorist in front of me but my brakes have suddenly gone out.

 

I noticed in the last couple of weeks pedal travel seemed to increase, but might have been my imagination, since I had been driving my truck a bit more, and had gotten used to those brakes.

 

Then over the weekend to this morning every now and then the pedal would go to the floor board with little effort, and little stopping effect, this happened only at low speeds. So I thought perhaps the caliper was sticking closed, since the speeds were slow there was nothing to kind of unstick and return it to the open position, meaning that since it was stuck in the braking position I had to push the piston to that position first before I would feel resistance. (Like when you do brakes the first couple of pumps are pushing the piston/pads to the disc...)

 

Well today it is all the time I push the pedal and it goes to the floor with no effort at all. and little stopping action. Happened at lunch so the drive back to the office was slow and with one foot on the e-brake.

 

I checked the fluid level and it was surprisingly dark but level was good, I check it regularly. No visible leaks anywhere. My factory service manual likes to blame the master cylinder (an internal leak).

 

Pads are all good/new too.

 

How does this sound? And how hard is it gonna be to fix? If someone has any ideas and needs more info just ask. I hate diagnosing my own cars, I always second guess my conclusions. Regardless, I think I am going to have to work on the master cylinder in some way.

 

Thanks for any advice.

[Silverado4x4]

Master cylinder is gone.

[asilverblazer]

By the way are these rebuildable?

[Draenor]

Andy,

....With the engine off, pump the brake pedal to remove any residual vacuum in the booster.

Hold pressure on the pedal while you start the engine. When the engine starts, the pedal should drop about a 1/4", this indicates that the booster is working properly.

Next,run the engine a minute or 2. Turn the engine off and press the pedal several times slowly. The first pump should be fairly low. The second and third should become slightly firmer. This indicates an airtight booster.

Next, start the engine and press the brake pedal, then stop the engine with the pedal still pressed. If the pedal does not drop after holding the pressure on the pedal for 30 seconds, the booster is airtight.

 

If you fail these then you need to replace the booster. I would also replace the brake hoses while you are at it, top it off with fluid and bleed the brakes.

[asilverblazer]

While playing with it in the parking lot I *think* I pass those. I can build pressure with the motor off but not with it on. I still need to verify this though.

 

Thanks guys, keep it coming.

[Draenor]

While playing with it in the parking lot I *think* I pass those. I can build pressure with the motor off but not with it on. I still need to verify this though.

 

Thanks guys, keep it coming.

Bad check valve in the vacuum port?

[asilverblazer]

Anything hard about bench bleeding master cylinders?

[General Lee 01]

The horn works don't it?

[asilverblazer]

It's not an "E-Brake" it's a "P-Brake" or "Parking Brake" not to be used for emergency braking purposes, thats why we have air bags now. I installed an aftermarket "E-Brake", I got it from a boat shop, in the marine industry they are better know as "Anchors" I had to buy a pretty good length of chain to go with it. I have part numbers if any one wants them.

 

Meh, regardless, I will test my luck at replacing a master cylinder. Bleeding it too I guess. I certainly can't get any worse than it is now.

 

On a positive note, my new truck hauled it home great! trailer was a little tongue heavy.

[Draenor]

You could always cut a hole in the floor board and stop like Fred Flinstone.

[Wingnut]

The horn works don't it?

 

[asilverblazer]

New master cylinder and all is well.