Cessna Parking Brake

Jaybird180

Jaybird180

Final Approach
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Jaybird180
I need some education on how the parking brake works. I’ve been doing transition training in a 182 and the parking brake is INOP. It’s not an issue if you remember to hold the toe brakes during pre-takeoff checklist and runup.

I know that I’ll get some frownie faces with this post so go ahead and get over with it, then give me some information I can use.
 
I suppose your not asking about pulling the handle out and turning it 90 degrees.. How does the system work? I imagine its a cable to the brakes. That would make it still work if the hydraulics failed. I forget what it is in a Cessna to be honest though. POH under aircraft systems.. All mine are at home. (At work now)

<---<^>--->
 
That's the thing; they don't work (worth a flip, in most)!

I will try to find a diagram.
 
p1l0t said:
I suppose your not asking about pulling the handle out and turning it 90 degrees.. How does the system work? I imagine its a cable to the brakes. That would make it still work if the hydraulics failed. I forget what it is in a Cessna to be honest though. POH under aircraft systems.. All mine are at home. (At work now)

<---<^>--->
Click to expand...

In the 172's (at least the mid 70's vintage) and similar vintage Cherokees it actually locks the brake pedals to hold pressure on the hydraulics. No separate, redundant system like in a car. That's why you have to press the brakes and then pull the handle. I've been warned never to leave them locked and walk away form the plane because it keeps strain on the hydraulics.

At least that's my understanding. An A&P will no doubt be along shortly to correct if necessary.

John
 
wow i didn't know that anyone used the parking brake
 
I've heard they aren't connected at all, which is why I'm asking the question and that the toe brakes work but the parking brake doesn't.
 
Why not simply get it fixed? its a simple cable that gets pulled when you pull the handle out, with a ratchet to hold it pulled until you release it.
 
Jaybird180 said:
I've heard they aren't connected at all, which is why I'm asking the question and that the toe brakes work but the parking brake doesn't.
Click to expand...
It's not airworthy if it isn't,
 
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In the 182 that brake handle pulls cables to tip the pedals forward and apply pressure to the master cylinders. Dead hydraulics means no park brake. It's not a good idea to leave them set for long periods; the fluid's pressure will vary with temperature changes and the pressure will either increase and maybe break or distort something (most likely the park brake mechanism) or it will fall and let the airplane roll. Use chocks. The park brake is good for getting in or out of the airplane while on a slope.

Parking with hot brakes will really heat the fluid and make trouble.

Some older Cessnas had a Bowden cable (like the carb heat cable) that pulled little latches upward on the top of the master cylinders. The pilot applies the brakes using the pedals, then pulls the knob, and releases the pedals. The latch snags the master cylinder pushrod and holds it. Supposedly. It's not reliable at all; it relies on friction caused by the cocking of the latch plate, and the hole in the plate wears and lets the rod slide up. Away we go.

Dan
 
jsstevens said:
In the 172's (at least the mid 70's vintage) and similar vintage Cherokees it actually locks the brake pedals to hold pressure on the hydraulics. No separate, redundant system like in a car. That's why you have to press the brakes and then pull the handle. I've been warned never to leave them locked and walk away form the plane because it keeps strain on the hydraulics.

At least that's my understanding. An A&P will no doubt be along shortly to correct if necessary.

John
Click to expand...

the later version 172/182 simply has a cable to pull the brakes on. early 150-172 has a catch to hold the master cylinder depressed. depressing the pedals allows the catch to fall away and release the master cylinder allowing it to extend.
any leak in the system will release these brakes.
 
Describe a situation in which you would trust the security of a Cessna to the reliable operation of its parking brake.

Run up?
Sloped surface?
To hold the a/c while you copy a clearance?

There's one device that ought to have been treated like the cig lighter; disable and placard it!
 
Tom-D said:
I have seen several aircraft destroyed due to the parking brake being inop or not used..
Click to expand...

The parking brake is a trap, you can't use it for anything reliably. But it's there, so the neophyte will try.
 
Tom-D said:
the later version 172/182 simply has a cable to pull the brakes on. early 150-172 has a catch to hold the master cylinder depressed. depressing the pedals allows the catch to fall away and release the master cylinder allowing it to extend.
any leak in the system will release these brakes.
Click to expand...

Ahh! Makes more sense to lock the master cylinder than the pedals and confirms how I was instructed to use it. About when did it change?

John
 
jsstevens said:
Ahh! Makes more sense to lock the master cylinder than the pedals and confirms how I was instructed to use it. About when did it change?

John
Click to expand...

The pedals are connected to the master cylinders, so it's the same thing in different terms. The cable attaches to the pin that connects the pedal's lever to the cylinder's pushrod.

Dan
 
Let'sgoflying! said:
Describe a situation in which you would trust the security of a Cessna to the reliable operation of its parking brake.

Run up?
Sloped surface?
To hold the a/c while you copy a clearance?

There's one device that ought to have been treated like the cig lighter; disable and placard it!
Click to expand...

Sloped surface. We' don't all live in Kansas.

Dan
 
Tom-D said:
the later version 172/182 simply has a cable to pull the brakes on. early 150-172 has a catch to hold the master cylinder depressed. depressing the pedals allows the catch to fall away and release the master cylinder allowing it to extend.
any leak in the system will release these brakes.
Click to expand...


Kinda like the catch that ya find on a door with a return/close cylinder. Designed to hold the door open when ya let it go.
 
Originally Posted by Let'sgoflying!
Describe a situation in which you would trust the security of a Cessna to the reliable operation of its parking brake.
Run up?
Sloped surface?
Click to expand...

Sloped surface.
Click to expand...

Not me, I would either chock it or tie it. Relying on the parking brake would be risky, imo.
 
Let'sgoflying! said:
Describe a situation in which you would trust the security of a Cessna to the reliable operation of its parking brake.
Click to expand...

The ramp where I refuel is slightly sloped. When I'm alone and need to get out of the plane to put the chocks on the wheels, I will trust it just enough to get out and do that, otherwise they are just weight.
 
I trust the parking brake on *my* airplane for one thing... Right in front of our hangar is flat and I'll set it while I close the hangar door. I should chock but I'll admit a slight laziness here for that one particular spot. If there's wind, I'll chock.

Otherwise we carry chocks in the back for everywhere else. A tiny toolbox with only essential tools, the cowl plugs, a first aid kit, and the chocks all wedge into the "hat shelf" nicely and add a tiny bit of weight at that far-aft station to help counterbalance the Skylane's nose-heavy tendencies.

I don't trust it but do set it during run-ups, etc. My feet stay on the brakes lightly, making setting them relatively worthless.

Also if you depress the brakes with your feet and then set it, the cable has less tension on it during setting so they're set "harder" than if you just yank on that flimsy handle trying to rip it out of the dash. Use your feet to set the pressure then pull, twist, and latch.

Never trust 'em. I treat that lever as a backup for my feet.
 
The only time they are of much value is if you need to get out on a sloped surface to put the chocks down. Even then I'd be trying to figure something else out. I trust the parking brake on light aircraft about as much as I trust the landing light. Which is pretty much not at all.
 
amazingly in all of the PA-28's I fly, the parking brake works very well. I don't use it.

I got in the habit with the 152 of holding the toe brakes automatically doing run ups or whatever. I figured it was a good habit that I want to keep, as I will undoubtedly fly aircraft without a functioning parking brake.
 
Tom-D said:
Why not simply get it fixed? its a simple cable that gets pulled when you pull the handle out, with a ratchet to hold it pulled until you release it.
Click to expand...

Not my airplane, otherwise I agree with you.
 
Tom-D said:
It's not airworthy if it isn't,
Click to expand...
Tom,

Not trying to start an argument, but curious what your take is on the recommendation to disconnect the parking brake in the 170?

It is a 'recommended mod' per the 170 Association. Supposedly it is to prevent the parking brake from being inadvertently set. I haven't touched mine since I bought it......but I also haven't tested it either.
 
dell30rb said:
amazingly in all of the PA-28's I fly, the parking brake works very well. I don't use it.
Click to expand...

That has been my experience too. The Cherokee parking brake is a different design and I believe it has its own cylinder. This is probably an artifact due to early Cherokees not having any toebrakes at all.
 
Tom-D said:
It's not airworthy if it isn't,
Click to expand...

Well then, all five aircraft in my logbook have been unairworthy. Including the two I have owned. I, personally, have never met a Cessna with an operating parking brake.

Not saying you're wrong...just that it seems to be quite common for them to be inop and no one (including me) seems to care or misses them.
 
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The setup in my 172B is very wrong. Whoever designed it never tried to operate it. It is a design FAIL. It is also one of those things that are known by all and not made a big deal of. Where I rented before I owned had no aircraft that had an operating PB.
 
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