Brake vibration noise

[wingit]

Hi Guys, I can feel and hear vibes under the feet.I think from rear brakes.
03 GL1800 champ solid axle trike. 26k miles
took this too a reputable trike company, biggest Champ dealer East.
A good mechanic rode at idle in a left turn, and you can hear and feel
the growling vibration, He didn't know what it was, They are busy
and suggested looking at it another day.

I took the rear brake discs off and saw they are worn at an angle
I think because a shim over the piston only covers half its face,
which I think causes un even pressure on the pads and piston.
The term is out of perpendicular stack of components.
I sanded the pads parallel measuring them W/in .005.. Pads are still 70%
and removed these "wrong shims"..I thought that was the problem.
Put back together and its making the same noise and vibes.
I did Tool & Die work 37 years and designed alignment parts for Cars,ATV's,
optical mfg. aircraft parts to medical device mfg. So maybe its just bad brakes ?
I think there has to be a reason you can see and identify.
I changed rear diff oil to see condition and the magnet. It looks OK
I'll take it down again and look for corrosion on the brake pistons .
Anyone heard of this ? Its just weird.
Happy day

 

[cavie]

Check the alignment with the calliper and the disc. I found it strange the there were 2 ea washers on the two caliper mounting bolts used as spacers.:xzqxz: Those are a pita to replace. You may have one washer missing.

 

[wingit]

Washers ... square to the universe ? or lost and wondering forever

Thanks for the help
We drug this down to Seminol FL from Mn for a couple months.
Its been the best winter Triking 2000 miles around here instead of wishing.
Almost got hit a couple times, friends said don't bring a 2 wheeler..hmmm.

You might have something, I'll measure the Piston faces parallel to rotor.
I can imagine the bracket might not be welded on square to the axle.
Only one Pad was off .040 end to end, the other 3 were about .010 /.015 off
Happy Day

- - - Updated - - -

 

[tndragonrider]

It might be a stupid question, but are the rotors warped?

 

[wingit]

Warped rotor ?

It might be a stupid question, but are the rotors warped?

Not stupid at all, That is more common on non trike bike rotors.
I had to replace one on an abused BMW1200 I bought with 3500 miles.
These solid cast iron rear trike rotors are thick mass that resist cracking
and I can't imagine making one of these bend in the mountain switchbacks.
We enjoy the switchbacks in the Rockies and Im curious how this Wing Trike
will do Up and Downshifting to save the brakes. The BMW's don't get too hot.
Thanks

 

[Future Triker]

This may sound like a silly question, but you mentioned in your original post that they could hear and feel the noise when making a left turn. Are you 100% certain that it's actually coming from the back end? This is a VERY common thing on GL1800 trikes from what I've researched.

There is an "alignment groove" on the front axle that is a marker for the fork on one side. If the fork isn't pulled out to match that mark, the front end will flex and the rotor will rub on the front end when making turns which causes the noise/grinding feeling you're describing. Below is a general internet search I did by typing in Goldwing 1800 front rotor rubbing, good information worth considering possibly.

https://www.google.com/search?q=golding+1800+front+rotor+rubbing&ie=utf-8&oe=utf-8

 

[wingit]

Its improved and the sound changed to a squeel at light braking.
I took the left side rear brake pads off, de bured and Its somewhat better.
The wear pattern is flat and the piston marks on the backside is uniform.
I used a small flat file to debur and clean the flats where the pad metal slides.
Also pad metal backing is always rough and crude with sharp edges.
By de buring the edges of the steel pad backing it might have helped.

Now I know its the rear brakes, One opinion was the rear or wheel brgs.
We feel better riding Fl more. Its 60+ in Mn today, and Fl also.
We hear bikes are out up there.We would be trying the ice gravel deiveway too.
It will be 70's all week here, and going back down in the great white north.
Im happier today
Thanks for the help

 

[Shimpy]

This probably won't help you much, but I also have a, what I describe as a groaning noise from my rear brakes on a Champion S/A trike. I never had this before until I had the brake fluid replaced and bled. It mostly showed up when the brakes were warmed up then eventually went away.......Now a couple years later after having my brake recall done and the fluids replaced and bled it has come back and is now starting to go away.

 

[wingit]

This probably won't help you much, but I also have a, what I describe as a groaning noise from my rear brakes on a Champion S/A trike. I never had this before until I had the brake fluid replaced and bled. It mostly showed up when the brakes were warmed up then eventually went away.......Now a couple years later after having my brake recall done and the fluids replaced and bled it has come back and is now starting to go away.

Shimpy ;Yours sounds like the same issue as mine.
My brake recall was done late December in Mn then brought it south in the 80's
My back and knee are sore from projects so Im waiting a few weeks to see
if the squeal stops. Harder braking is quiet, soft brakes is noisy 60% of the time.
Im hoping this will improve when the pads seat in, but they were seated when flushed.
Thanks for the help, maybe others can benefit from the post.
The squeal sounds like this Beem Bot when She's hungry. Happy Day