Brake Vaccum Question

[LCAM-01XA]

I have a little different problem -- and it just started.
When I apply the brakes (which work fine), the pedal wants to stay down (and keep brakes applied).
Is there a spring on the pedal that may have broken? Or is there some valve in the booster that may have failed?
I'll get out and check it as soon as it warms up a bit - I'm getting too damn old to be crawling around in the snow.
TIA
<als>

should have added - I can pull the pedal back up from behind, and it stays up until next time.

There are 2 spring inside the master cylinder, but if they were damaged chances are the brakes would drag even after you manually pull the pedal back up. This is because the brake booster can only push on the pistons inside the master cylinder, it cannot return-pull them, so when you pull back on the pedal you're pulling the booster diaphragm back to "idle" state, the pistons in the master cylinder then return on their own. If you have no brake drag after you manually pulled the pedal back, then the master cylinder is fine, and you should e looking at the brake booster.

The booster has its own return spring, it is actually what returns your pedal as well because Ford brake pedals are just free hanging and do not have return springs on their own. If that spring is shot, or worse the diaphragm is getting wonky, the booster will want to hold the brakes applied for you. The vacuum brake booster is really not a user-serviceable assembly, you have to just replace it, and it's good idea to do so ASAP as there are numerous reports of bad boosters not just holding the brakes on for you, but actually applying them full force every time you step on the pedal.

 

[fsmyth]

Thanks. That is what I needed to know.
And they do try to apply hard sometimes.
<als>

 

[aiyana7.3]

So here's an update: I found that it was a combination of a leaking rear wheel cylinder and very poorly adjusted brake shoes. Thanks everyone for all the help with this!

One more question though... the brakes are working great now but the brake pedal makes a hissing noise when it is pressed down before halfway, when it is being let up before halfway, and when it is held two inches down... does anyone know what this is? It always made a quick psht noise but now it is a more sustained pss noise..

 

[79jasper]

Brake booster.
Probably bad/going bad.

Sent from my USCC-C6721 using Tapatalk

 

[aiyana7.3]

After a minute of driving it stopped so I'll keep an eye on it. Thanks for all the help everyone I really appreciate it! I'm real glad I joined the site it has been so helpful!