PA-12 Brakes

[PA-12 Super Cruiser]

I have noticed in the past couple flights that it takes a little more travel to engage my heel brakes. This occurs on the left and right. I have the old style expander brakes not the Cleveland upgrade. Could this be caused by the change in temperature? Can I add fluid? Could it be the rubber diaphram?

Jeff

[piperjak]

Just add fluid to your cylinders -That should take care of your problem. Those diaphrams are pretty durable and should last a good 20 years.

[Steve Pierce]

Try adding fluid. That i probably the problem. Sometimes the pads are worn and don't grab. They can be shimmed.

[PA-12 Super Cruiser]

What kind of fluid do I add (Avations brake fluid, auto brake fluid...??

Jeff

[lowandslo]

5606

[FlipFlop]

What kind of fluid do I add (Avations brake fluid, auto brake fluid...??

Jeff

DO NOT, repeat, DO NOT use automotive fluid!... It will gum up the works and you'll be fixin' instead of flyin'...

5606 is the mil-spec fluid that you use... Get it from your A&P or Chief Aircraft, Aircraft Spruce and Specialty, etc...

[Fortysix12]

The Goodrich brakes can be shimmed as earlier stated,however I prefer to charge them for a full pedal. The previous owner built a pressurizing unit from an old T6 tail wheel assembly. You'll need to come up with your own unit and couple of other parts including a small floor jack to raise your plane while pressurizing the bladder from the brake bleeder. Give me a call cuz it will be easier to explain the process over the phone. But once your have the tools it only takes about fifteen minutes every 2-3 months. and nothing like a full pedal. That my take the situation
(800.497.0112)

[PA-12 Super Cruiser]

Thanks for the info. 94super18 I will give you a ring.

[Mikey]

The procedure I used w/ the Scott diaphram cylinders was to add fluid from the bottom (brake bleeder at the wheel, if you have one) until the cylinder resevioirs were full (w/ the filler plug removed), then disconnect the linkage from the front heel pedals so that you can pull the brake cylinder lever to the maximum aft travel. While holding it back, top off the reservoir w/ 5606 and replace the filler plug before releasing. It helped some, but the ultimate fix was installing 6" Clevelands and the ???River brake boosters. I had already installed the Clevelands before the brake boosters, so don't know first hand how well the boosters w/ work w/ the old expander tube brakes. My understanding is that the old Scott diaphrams are a "low pressure, high volume" system as opposed to the Brake Boosters which are a "high pressure, low volume" system which is more suited to the requirements for disk type brakes.
Hope this helps,
3719Mikey

[cubpilot2]

If you are lucky enough to have the hydraulic park brake valves installed then it is quick and easy. Depress the pedal and set the park valve, pull the reservoir plug and top off with fluid.

[Steve Pierce]

Good advise Ed. That is how I do it and it works great.