Brakes got soft

[HotWheelsBurban]

I think we have different problems. Mine, I think though need to check further, is due to piston seals pulling the pistons back too far. Mine doesn't make the hissing noise.

The hissing noise - isn't that because you have reached full travel - as when it happens with full steering lock?

On another car way back, I had the pedal go long because of a heavy stop. The adjuster in a rear drum had broken. Maybe you have the same.

Check your brake hoses too! They do go bad, and my cousin's truck wouldn't bleed properly until he replaced the rear hose. My truck had an obstruction in the right front brake hose and it heated up enough to catch on fire and melt the antilock sensor on the backing plate. That piece alone is $100. So l replaced both front hoses, the calipers and pads, repacked the wheel bearings and pressure bled it. Good pedal travel and feel after that, been driving it in Houston traffic and on the highway loaded to shows; no issues with it since then. Brake bleeding takes some time but it's well worth it; a pressure bleeder will help you a lot, and you don't have to have a helper to push the pedal down. Good luck with your truck, hope this helps you get it done

 

[HotWheelsBurban]

Hydroboost is real sensitive to fluid levels, if you have a leak in the power steering system that can make it act up

 

[Pinger]

Check your brake hoses too! They do go bad, and my cousin's truck wouldn't bleed properly until he replaced the rear hose. My truck had an obstruction in the right front brake hose and it heated up enough to catch on fire and melt the antilock sensor on the backing plate. That piece alone is $100. So l replaced both front hoses, the calipers and pads, repacked the wheel bearings and pressure bled it. Good pedal travel and feel after that, been driving it in Houston traffic and on the highway loaded to shows; no issues with it since then. Brake bleeding takes some time but it's well worth it; a pressure bleeder will help you a lot, and you don't have to have a helper to push the pedal down. Good luck with your truck, hope this helps you get it done

Hoses crossed my mind too - especially with the slow pedal return (I've seen the scenario you had before, collapsed internally and trapping the brake on. I think those that grip/squash hoses to seal them for caliper removal cause that. Bad practice).

Hydroboost is real sensitive to fluid levels, if you have a leak in the power steering system that can make it act up

Crossed my mind to check PAS fluid as well - and will do. My brakes though, seem to have come good on their own with nothing more than occasionally prods of the pedal while I've been working on other things. Seals and/or Hydroboost shenanigans I think was the cause of all this. Hopefully (I'll know when I next drive it) it is fine now.

 

[JavaMan]

Hydroboost is real sensitive to fluid levels, if you have a leak in the power steering system that can make it act up

My brake fluid has been midway between min and max for a while. Guess I'll put it at the max from now on.
My power steering does have a leak that I've been watching the past few years 14k miles. Used about 1/2 a quart in that time. Was not really worried about it, still can't figure out where that's leaking, gets oil all over the place so it's hard to pin down where it's from. For the most part not enough leak to drip down to the ground, just all over the underside.

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[HotWheelsBurban]

Yes the air forces under the vehicle when you drive blows oil and other fluids everywhere, and that makes leaks hard to diagnose. Best thing is to get it up in the air so you can clean the engine and chassis off,then you've got a better idea where it's coming from. I know it's not always easy or possible to do that though. Good luck, hope this helps

 

[PANHEAD]

this is panhead . and this is for you thin skinned a-holes.. a gearhead used to take criticism but I guess times HAVE CHANGED for the worst. you all can kiss my ass. signing off

 

[JavaMan]

Well, it fixed itself today. Either adding a little bit of brake fluid, just topping it from midway between min and max, or just sitting there for a few days. But the pedal feels normal again.

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[stutaeng]

My brake fluid has been midway between min and max for a while. Guess I'll put it at the max from now on.
My power steering does have a leak that I've been watching the past few years 14k miles. Used about 1/2 a quart in that time. Was not really worried about it, still can't figure out where that's leaking, gets oil all over the place so it's hard to pin down where it's from. For the most part not enough leak to drip down to the ground, just all over the underside.

Sent from my SM-G965U using Tapatalk

My K3500 had a huge mess with PS fluid leaks. I changed the hydroboost. They are known to leak. After that, I sprung 2 leaks on the hoses going to hydroboost/steering gearbox. I had my son turn the steering wheel and it would shoot about 3 ft away.

Prior to all of this, I had the PS pump shaft break. I was going to the landfill with 3,000 lb of rock and heard a somewhat louder whine, but didn't think much about it. At the first stop light the brake pedal didn't return and after I took off the steering got hard. No steering and no breaks made it pretty scary. Luckily I was able to return home. When I tried to remove the PS pump pulley the shaft just slid out!

They actually recommend you replace all PS hoses because they degrade inside and that stuff gets into the system. I think I read that on the instructions on the hoses I bought.

At the minimum I would replace leaky hoses and bleed all of PS fluid out and put fresh one.

 

[Pinger]

Prior to all of this, I had the PS pump shaft break. I was going to the landfill with 3,000 lb of rock and heard a somewhat louder whine, but didn't think much about it. At the first stop light the brake pedal didn't return and after I took off the steering got hard. No steering and no breaks made it pretty scary. Luckily I was able to return home. When I tried to remove the PS pump pulley the shaft just slid out!
.

That was what was happening to mine - pedal not returning.
Checked PS fluid level and it was at the 'add' mark (so topped it up). Would the slightly low level in conjunction with using most of the pedal travel 'exercising' the pistons to make sure they weren't sticking (calipers detached) have caused my problem? Which seems to have cured itself though I'll wait until after tomorrow's 100 mile trip to be certain.

 

[stutaeng]

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.