Parking brake hangup

[dspender]

I have 100 hrs on my 10 in the first 12 months. My brake discs have been under such heat from hung up brakes they have turned a blue pink color and have substantial wear grooves. I need to replace the pads and discs. I have read about fixes with the pedal attachment using an AN3-56 bolt and springs to the master cylinder shaft. However, after much research I think I caused this from the PVPV-D parking brake manufactured by Matco I purchased through Vans. I believe I have the moveable lever when in the "neutral position or open" somewhere in the 'transition zone', 27.5 degrees either side of perpendicular. Matco tells me if the lever is in the transition zone or further toward the closed position, pressure applied to the brake pedals will cause increased brake line fluid pressure to persist and the brakes to hang up. In order to ensure no pedal pressure remains in the line when I am off the pedals, the moveable level on the parking brake needs to be 'outside' the transition zone and at least 27.5 degrees or greater from perpendicular toward the open position.

Sound reasonable?

[climberrn]

I don't remember the exact degrees, but I made an aluminum bracket that has hard stops open and closed so I can feel the stop with the activation cable.

I know this doesn't answer your question directly, but have you added the "return spring mod" to all your master cylinders? There was an excellent write up, and the springs make sure all pressure is off the brakes at the master cylinders when the petals are not pressed. Could be the master cylinders keeping a little load on the system.

[dspender]

I have read many of those threads. I have purchased the AN3-56 bolts and springs but intend to first make sure the parking brake is fully releasing. Talked with Matco today and they said , as has been noted on this forum before, they don't like the springs riding near the master cylinder piston, in case the shaft gets scratched and leads to leaks around the shaft seal.

[climberrn]

Yeah. After writing about the springs yesterday it got me thinking about that. Need to check and make sure the springs are not touching the shafts. Let us know what you figure out is causing the problem.

Are you positive you are not accidentally dragging the brakes while taxiing? I ended up getting some rudder petal extensions because it was very difficult to stay off the brakes. That helped.

Now back to your original question.....

[Caveman]

Perhaps this .pdf will help?

http://static.veracart.com/matco/ite.../document1.pdf

Joe

[9GT]

Originally Posted by dspender

I have read many of those threads. I have purchased the AN3-56 bolts and springs but intend to first make sure the parking brake is fully releasing. Talked with Matco today and they said , as has been noted on this forum before, they don't like the springs riding near the master cylinder piston, in case the shaft gets scratched and leads to leaks around the shaft seal.

Over 500 hours on the Cozy MKIV equipped with the return assist springs, and near 100 hours on the RV-10 before I sold it with zero issues of the springs "scratching" or "gouging" the shafts causing leaks. I must have done something wrong.