Parking Brake Pedal Not Staying Down

[Tiggie]

The '90 has this new fangled push on/push off parking brake. The "peg" part that locks the pedal down is not engaging. I can manually use my finger to push the peg down while holding the pedal down, and it will hold. It releases as it should after this. But it is not engaging itself when trying to apply the parking brake. Fwiw the parking brake is good when you use the pedal - it just doesn't lock down.

And how does all that vacuum crap work on the thing? It's got two vacuum actuators doing something. I don't like new fangled.

[85crownHPP]

There's probably a spring behind the peg that's gone... I'll try to remember to give mine a look Maybe soak it in WDetc. in case it's just full of dirt.
I love the auto release, I even fixed it in the p72 when I had it... The half moon piece attached to the steering column is the vacuum selector switch, they usually are leaking. The other is the actual pulloff that gets fed by the other one.

[gadget73]

thats actually a good point. Does it work when the engine isn't running? If that stupid valve thing is bleeding vacuum through it you might find that it doesn't hold.

[Tiggie]

Doesn't work ever. Won't have time to look at it until later this week/weekend, but I am wondering if it vacuum related. It's like it's got no vacuum to the dash. Will be checking the vacuum tree, assuming that's where the source is.

[His Royal Ghostliness]

Why do you say it's like there's no vacuum to the dash? do your HVAC vents operate properly? Like, are they stuck on defrost all the time, or can you actually switch to panel and floor? If the vents work properly then your dash vacuum supply is fine.

The e-brake and the dash use separate vacuum lines btw, IIRC the dash is a thin (like 1/8") black one and the e-brake is a larger (3/16" or 1/4") white one. Both hook up to the vacuum tree on the engine side of the firewall tho.

Pull the vacuum line off the e-brake pedal actuator, if the pedal starts locking down properly you have an issue with the vacuum switch. To verify this pull the supply line off the vacuum switch and plug it (the line, not the switch), if all other vacuum-operated devices start working properly you can leave things as they are, or you can look for a NOS switch.

If pulling the line off the e-brake actuator doesn't change a thing, then its likely as 85crownHPP said that you have some spring issue there. How you gonna get to it idk right now, don't have one of them things to look at.

[Tiggie]

Vacuum to the dash now. Previously none functional HVAC started moving around yesterday. And drumroll: parking brake works perfectly! What fixed it? Not me. I've just been starting it up and letting it run. I did spray the parking brake mechanism with wd40 before I posted this. Maybe it penetrated enough to do something.

Let's hope this is a self healing car like my 88 that years ago lost first gear for weeks only to get it back and keep it ever since.

[85crownHPP]

Of course you fixed it, you restored the source of its force