Brake pedals uneven

[drak130]

Hey All,

So was teaching my son how to taxi the plane and every time he tried to stop he would turn to the right. I told him to “press on both brakes evenly”, he said “I am”. Well he was deflecting the pedal the same but the right pedal is engaging before the left by a decent amount. I tried pumping the left brake to see if they were spongy from air but does not seem to be the issue. Is there a way to adjust the pedals for even engagement? Did a forum search but only parking brake issues came up.

Thanks in advance

Tim

[maules.com]

The pushrods behind the pedal top are adjustable, but question is, how did it get that way ?

[G-MAWL]

Hi,
Check both calipers have the same diameter pistons ! When I bought mine it had 1 3/4" on one side and 2" on the other! Made life interesting.

Derek

[andy]

It's possible that the rudder cables have been adjusted to correct a rigging problem. That might put one rudder pedal at a different position than the other and make it a little harder to apply even braking.

[Kirk]

I’ve had issues on my M5 bleeding the left side brakes. It resulted in something similar to what you are describing. Here are a few things we struggled with on the brakes:

My IA found the seals in the actuators at the pedals were allowing fluid to pass through when brakes were applied hard. Rebuilt the actuators at the pedals.

Actuators were rigged unevenly. Easy adjustment.

Apparently, there are differing brake systems on the Maules. My M5 having the “older” system. The following worked for my system.

Had a heck of a time bleeding the system out. Got it right after finding a thread on here describing the brake bleed process. Do a search for that thread; but here is my recollection of what it takes.

Bleed up from brake calipers to pedals.
There is a shuttle valve between pilot and copilot sides which allows whoever is pushing hardest to control the brakes. Air can get trapped in the line between pilot and copilot sides. That air can move around resulting in brakes applying unevenly.

To bleed one side (pilot-copilot). Depress the pedal at where you choose to start first. We started on pilot side. This sets the shuttle valve closed to copilot side.

Pump fluid in from caliper. Attaching a fitting (1/8” NPT?) to the brake actuator makes things less messy. Pump fluid until no air is present. Close bleeder at the caliper.

Next depress the pedal at the other seat, setting the shuttle valve open to that part of the system. Repeat bleeding process.

It may take several tries to get all the air out. We finally got mine right after about 4 tries.

Hope that helps.

Kirk

[maules.com]

One more thing.
There is a Service Bulletin regarding the welded bracket that supports the brake cylinders to the airframe.
The weld can crack and bracket can become displaced downward. Definitely check all four brackets .

[wtxdragger]

It's possible that the rudder cables have been adjusted to correct a rigging problem. That might put one rudder pedal at a different position than the other and make it a little harder to apply even braking.

Is this a real thing?
I don't see the differential braking, but my trim has changed.
I had an MT 3 blade installed on the M7 on my previous annual and mentioned to my mechanic that the rudder pedals were not even and asked if he could get them level. After the prop install,I noticed that I had to pull in more right rudder to trim, but didn't even think about this being a possibility. Every time I fly, my pea sizes brain thinks there are a multitude of problems, well not problems, but something changed with the airframe to create the out of rig situation. I kept going back to the prop install, but couldn't see a connection.
She's been beat up on pretty hard her whole life, but we kinda like each other.

[andy]

Center your rudder and ailerons from outside the airplane, release any right rudder trim with the T-handle and then take a look at the position of your rudder pedals and the servo tab on the rudder. That should tell you if the rudder cables have been adjusted. The turnbuckles near the rudder control arm at the tail are where an adjustment could be made.

[Andy Young]

The rudder centering springs (if your plane has them) can also pull the rudder in one direction, if not rigged evenly. One of them is anchored by an adel clamp to a tube that runs diagonally. I have had that clamp slip along the tube, reducing the tension on that spring, allowing the other spring to pull the rudder off-center.