Brakes got soft

[HotWheelsBurban]

Not sure about sticking calipers. I don't think that would cause the pedal to not return, but not certain. For sticking calipers, just take it apart and grease the pins. You can inspect for uneven wear on pads.

My wife's 2013 T&C minvan had sticking calipers. It made a grinding noise when wet. I thought it was normal. Finally, when I took it apart one of the pads was chewed up into the metal. The matching pad was almost full (also only this pad had the squeal metal thingy, so brakes never squealed.) Rotors were damaged, so had to get new ones too.

Yes it's surprising how many people don't realize that the brake hardware should be properly cleaned up and relubricated with appropriate grease. Some people don't because it takes time that they don't want to spend and some people just don't know. My dad always impressed upon me that it was time and effort well spent to do the job right, especially with brakes. That was one of my jobs early on when we worked on a car or truck, to clean up the bolts and hardware. Then he showed me how to put the antiseize or grease on the parts.

 

[bigfutz]

My brakes recently started feeling a little soft. No noticeable hissing from the vacuum booster (yet), but I’ve changed the booster before on one of these. I also noticed my fluid is between min and max, so I’m trying that (easiest) first.

 

[Schurkey]

No external leaks - does a leaking master cylinder just leak back to the reservoir?

Or into the booster.

So does that mean it's just a minor worry, not a stop driving and get it fixed thing?

Brakes are ALWAYS a "get it fixed thing".

I think though need to check further, is due to piston seals pulling the pistons back too far.

That's exactly how low-drag calipers are supposed to work. Thus the need for Quick-Takeup master cylinders.





If a person notices details, the fluid reservoir of a disc-brake system is nearly always much larger than a reservoir for a drum-brake system.

Assuming the pads are wearing evenly, the brake fluid level is your indicator of pad wear. When the fluid level is near "MINIMUM", the pads are worn out.

For fukk sakes, don't screw-up this warning system by adding fluid to a disc brake reservoir except at pad-change time. At pad-change time, the fluid should be flushed, and returned to the "Full" mark with the pads pushed up to the rotors.

Of course, if you need to add fluid 'cause there's a leak, and you need to get home, sure. Otherwise, leave the fluid level alone.

 

[sewlow]

When my brakes get to feeling a bit mushy/low, I've found that adjusting the REAR brakes will bring the pedal back up, & make it firmer too.
The drum brake self adjusters on these trucks are crap. The notches in the wheel are large, so the shoes have to wear down quite a bit before they'll ratchet up. ...and even then, they don't self adjust enough to get the pedal back up off of the floor or make it fell firmer.
To top it off, GM discontinued the use of a punch-out window so as to be able to set the shoes without having to take the wheels off! WTF'nF?

 

[Marauder]

Since you have a hydroboost, how is your power steering system? Is it leaking or low fluid or pump going out?

have you flushed the power steering system ? The smallest amount of debris in the system can start plugging things up in the hydroboost, that is why it is highly recommended that you put a inline filter for the power steering system.

....the vacuum bleeding the power steering with the hydroboost (even w/o) will get more air out of the system than other procedures we are used to. I helped replace a hose and it just makes things easy, for me at least.


Update.... copied from a article I found.

“Hydro-boost systems use hydraulic pressure from the power steering pump to amplify brake pedal effort. Pressurized fluid also flows through the hydro-boost to the steering gear to provide power steering. When the brakes and steering are at rest, pressure runs about 150 to 200 psi. Expect to see about 450 to 600 psi during normal brake application or when the wheels are turned.

As more demand on the system takes place, the power steering pump can increase working pressure to 1200 psi or more. During hard brake application, the hydro-boost unit can create pressure in the master cylinder of more than 2,000 psi. This converts into some serious stopping power for heavy vehicles.”

 

[Aqua]

When my brakes get to feeling a bit mushy/low, I've found that adjusting the REAR brakes will bring the pedal back up, & make it firmer too.
The drum brake self adjusters on these trucks are crap. The notches in the wheel are large, so the shoes have to wear down quite a bit before they'll ratchet up. ...and even then, they don't self adjust enough to get the pedal back up off of the floor or make it fell firmer.
To top it off, GM discontinued the use of a punch-out window so as to be able to set the shoes without having to take the wheels off! WTF'nF?

Hey Sewlow. I've done this and adjusted rear they seem fine. But now at times it feels like they get really ******* the first press but then normal after that. Not fun when driving. Keeping a distance. The hard breaks makes me wonder if it's the booster. Any thoughts??

 

[Aqua]

Hey Sewlow. I've done this and adjusted rear they seem fine. But now at times it feels like they get really hard/tough the first press but then normal after that. Not fun when driving. Keeping a distance. The hard breaks makes me wonder if it's the booster. Any thoughts??