Brakes

[seebruce]

A few more question. I'm having trouble applying the brakes, especially when turning. The pedals rotate so far back that I can hardly bend my ankles far enough to engage the brakes. Is this normal? The log books indicate that both disks and pads were replaced 2 annuals ago and only have a few hours on them. Does anyone know if there is any way to adjust the brake linkage to lessen the travel at the pedal?

Also I'm noticing that one of my speed brakes doesn't completely retract into the wing. It sticks up about 1/2 of an inch. It pushes down easily by hand and doesn't seem to have any binding. These are Precision brakes. Has anyone had this problem?

Bruce

 

[N6843N]

Does it feel like air or like there is nothing and then a good hard pedal? There are adjustments but you would have to question why that had changed. The caliper o-rings may be letting air in to the system, which is what I would suspect. You said "back" I assume you mean the rotate to far forward.

[seebruce]

I just purchased this plane a month ago and it was this way when I got it. The brakes feel pretty solid but I've noticed that the braking action seems to get stronger after applying pressure to the pedal. This happens without applying additional pressure.

Bruce

[seebruce]

No, but he plane was fresh out of annual when I bought it and there is no leaks. This is the first Mooney I've owned so I'm still trying to get a feel for it. How can the fluid level affect the actuation point at the pedals.

Bruce

[seebruce]

Thanks Jim, This maybe normal for a Mooney. I'm used to Pipers, I've owned a Seneca II for the last 9 years. Great plane but the cost of fuel just got too crazy.

Bruce

[j3gq]

Hi Bruce, our 205 has the same problem with the brake pedals. Is it normal ? I don't know. I am not sure it's always been present, think it started about one year ago. At least it got worse. But you can save a few bucks ... this maintenance didn't help: drained and replaced break fluid, checked system for leaks, replaced linings. Operationally it helps to ignore the problem in such tight turns step on the other pedal. And it saves tire rubber. Please keep me posted on any findings on your side. AJ

[seebruce]

Thanks AJ, I'll try that. I was told by the tech at Mooney that there is a adjustment in the linkage. But I have the parts and service manuals and as far as I can see the in no threaded rod ends that could be adjusted. I'll post if I come up with a solution.

[jlunseth]

I am having a similar problem with my M20K 231, but it also only shows up when I have one pedal advanced towards the floor relative to the other.  For whatever reason, maybe the rigging to my front wheel is wrong, but it seems that the left pedal needs to be further forward in order to stop the plane when it is going straight ahead, if that makes any sense.  What helps for me is that when I really need the brakes, such as for run up, I make sure to square up the rudder pedals and not worry about squaring up the front wheel.  Then the brake pedals are fine.  I have noticed that it has gotten worse though, so am going to have it checked at annual.

[seebruce]

I found that the master cylinders have a threaded rod end on the end of the shaft where an adjustment can be made. The master cylinders are located, on the M20's, above the bottom panel just behind the the firewall on the left side.

[j3gq]

Hallo, I hope you are still following this thread even so it's been a while. My mechanic has been sleeping over it and come up with a potential fix. The symptoms seem to indicate a problem in the "parkbrake" valve. This could explain why the left pedal is more susceptible than the right, and explain why it gets worse after the brake has not been used for a while.

We will open the valve and check its O-rings in the coming days.

Will keep you posted (but let me know whether you still follow this).

AJ

[seebruce]

Yes I'm still following the thread. I had the rod ends on the master cylinders adjusted so the pedals don't need to rotate as far front to engage the brakes. It helps with the braking but  feels strange because the top of the pedals are always slightly depressed and pushing back againsed my feet.

[Jeff_S]

This may not quite be the same but I had a brake issue on Saturday. In my normal routine the first thing I do after I've strapped in is test the brakes. The right brake pedal went all the way to the floor and had NO resistance...clearly not a good thing. Luckily my A/P was working on a plane right next to mine and so we checked the brake fluid reservoir and it was completely empty...whoops! He bled the right brake line and we filled the reservoir and then all of a sudden I had more braking power than I could remember.

This is a new plane for me as well so I'm getting used to what's normal and what's not. But I did a short refueling hop on Saturday after the fix, and on rollout at the gas-stop airport I actually locked up the brakes briefly because I had so much more braking power than usual. There is no evidence of a fluid leak anywhere but now one more think to look for on preflight. Oh joy...

[seebruce]

Does it seem like you must push the top of the pedals excessivly far before they actuate the brakes?

[Cruiser]

brake fuild does not evaporate. Maybe the mice are drinking it?

[Jeff_S]

I would think that if the mice were drinking brake fluid I would see a lot of dead rodents with pink bellies! But I take your point that such a sudden disappearance of brake fluid may be indicative of a leak somewhere, to which I would have to agree. That's why it's part of a regular check now!

[Earl]

Quote: seebruce

A few more question. I'm having trouble applying the brakes, especially when turning. The pedals rotate so far back that I can hardly bend my ankles far enough to engage the brakes. Is this normal? The log books indicate that both disks and pads were replaced 2 annuals ago and only have a few hours on them. Does anyone know if there is any way to adjust the brake linkage to lessen the travel at the pedal?

Also I'm noticing that one of my speed brakes doesn't completely retract into the wing. It sticks up about 1/2 of an inch. It pushes down easily by hand and doesn't seem to have any binding. These are Precision brakes. Has anyone had this problem?

Bruce

 

[carusoam]

Searching for Hydraulic fluid leaks... If it is not in the reservoir, it had to go somewhere....

Quote: Jeff_S

I would think that if the mice were drinking brake fluid I would see a lot of dead rodents with pink bellies! But I take your point that such a sudden disappearance of brake fluid may be indicative of a leak somewhere, to which I would have to agree. That's why it's part of a regular check now!