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Why do my brakes groan?

Daddyman58

Daddyman58

Well Known Member
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Both my brakes make a groaning sound when the brakes are applied. The pitch is slightly different from left to right. This is a mystery to me.
The brakes work perfectly. They stop well. They track perfectly straight. Nothing is rubbing. The pads are wearing evenly.
Is it possible the support plate for the wheel pant is the culprit noisemaker?
Daddyman
IMG_7097.JPG
 
Call it a "feature". Start worrying when the "groan" stops........... :cool:
I wish that was all I had to worry about.....

More seriously........ "Groan" is "Vibration". Usually mid-frequency. Soft hoses to the brakes can cause it. Brake pad hardness or softness can cause it. If you can't feel it in your brake pedals, it's not likely the discs.

If it's happening during taxi when the brakes are not being applied, then the brakes aren't releasing fully.

Hope this helps a bit.....
 
Does the "groan" end once there is notable brake pressure? Meaning it only lasts from initial movement of brake pedal until some resistance is met? If so, the caliper is likely being biased inward or at a tilt by your flex hose. Since the hose is a flex hose, inward (towards aircraft centerline) bias is unlikely, but twist could be doing it. Try loosening the B-nut slightly and rotating the hose in one direction or another to remove the twist.

The inboard brake pad should be flat against and just touching the disc when not being actuated.
 
PCHunt said:
Call it a "feature". Start worrying when the "groan" stops........... :cool:
I wish that was all I had to worry about.....

More seriously........ "Groan" is "Vibration". Usually mid-frequency. Soft hoses to the brakes can cause it. Brake pad hardness or softness can cause it. If you can't feel it in your brake pedals, it's not likely the discs.

If it's happening during taxi when the brakes are not being applied, then the brakes aren't releasing fully.

Hope this helps a bit.....
Click to expand...
Pete,
It does help.
It only happens during application of the brake.
No feel in the pedal.
Stainless steel braided hoses.
I'm heading to the hanger now to see what type of pads I bought (10 pack from Grove).

I did think about ignoring it completely and simply turn up the radio.

Daddyman
 
Daddyman58 said:
Both my brakes make a groaning sound when the brakes are applied. The pitch is slightly different from left to right. This is a mystery to me.
The brakes work perfectly. They stop well. They track perfectly straight. Nothing is rubbing. The pads are wearing evenly.
Is it possible the support plate for the wheel pant is the culprit noisemaker?
Daddyman
View attachment 76482
Click to expand...
What gasman said.
I have had this issue before and chamfering the edges of the brake pads, where they meet the disc has always made the groan disappear.
You should be able to do this without replacing the pads. Just use a file to hit the edges and reinstall.
 
sf3543 said:
What gasman said.
I have had this issue before and chamfering the edges of the brake pads, where they meet the disc has always made the groan disappear.
You should be able to do this without replacing the pads. Just use a file to hit the edges and reinstall.
Click to expand...
Steve,
I don't mind changing the pads as it is not a big job.
Being able to use the same ones?-Genius.
Daddyman
 
sf3543 said:
What gasman said.
I have had this issue before and chamfering the edges of the brake pads, where they meet the disc has always made the groan disappear.
You should be able to do this without replacing the pads. Just use a file to hit the edges and reinstall.
Click to expand...
Steve,
I did feel the wheel disc yesterday for any grooves, and although smooth, I thought at the time, a "bit too shiny".
Daddyman
 
I may have a similar 'groan' in my brakes. In my case, it's only when the airplane is sitting still and you bump or move it slightly...almost anywhere on the airplane. I don't hear it during taxi, or even when pushing the plane to a roll. Only when it's sitting still and the airplane moves a little.

Feeling around the brakes it is apparent this this comes from the brakes on just one side.
 
My 6A did that the entire time I owned it, through two sets of pads - nothing made any difference and I just lived with it. The brakes always worked exactly as I needed them to, but I did feel a little self-conscious about it when visiting other airports. None of the factory iron was acting up and making a spectacle of itself, just my little homebuilt.
 
We used to own a Rans S7 that had the same Cleveland main wheels and brakes as are used on the RV10. Our brakes moaned nearly every time they were used, my wife was embarrassed to fly it, with all the audible commotion. I changed pads, changed from Cleveland to Rapco to other aftermarket pads... all moaned the same! I gave up after spending many hundreds of dollars. I always thought it was because the Rans S7 was only a 690 pound plane, with brakes that were designed to stop a 3500 pound plane.
 
Accelerate to 40-45 kts and perform an emergency full stop braking.
Repeat 3x in succession
This will condition the new pads
Do it on turf surface to avoid tire damage from a blocked wheel in case you press too hard.
 
RV8JD said:
Many folks no longer condition new pads as such. But if you choose to, below are Grove’s instructions, which are contrary to those in the above post. Be careful not heat them up so much that you cause a brake fire with the tight wheel pants on the RVs. Some conditon the brakes with the pants off to allow for adequate cooling.

Ref --> https://www.groveaircraft.com/ica-wb.pdf

View attachment 76619
Click to expand...
Exactly what I do to break mine in.
 
RV8JD said:
Many folks no longer condition new pads as such. But if you choose to, below are Grove’s instructions, which are contrary to those in the above post. Be careful not heat them up so much that you cause a brake fire with the tight wheel pants on the RVs. Some conditon the brakes with the pants off to allow for adequate cooling.

Ref --> https://www.groveaircraft.com/ica-wb.pdf

View attachment 76619
Click to expand...
RV8JD,
Yep, this is what I have done for years, and did during this particular set.
Daddyman
 
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