Saturday, September 26, 2009

Accordion Bass Mechanism Repair Part 3

Accordion Bass Mechanism Repair
Part 3

To remove the next set of 40 button rods
from the Minor and Major chords, you will
have to remove the plastic retainer strip
which separated the “Dim/7th” chord rods
from the “Min/Maj” chord rods. It is a very
thin plastic strip which rests in a slot that
runs the length of the guide which retains
these bass button rods. This retainer strip is
held in place by a series of four or five tiny
black plastic pieces which are glued in
place to keep this retainer strip from
popping out of it’s location.

You will have
to remove these tiny plastic pieces using
your jewelers screwdriver or a small sharp
chisel to pry them loose. Before you pry
them loose, cut a thin strip of masking tape
and stick it to the top of the strip you are
removing, so that when the strip comes
loose it won’t go flying but will be retained
by sticking to the tape. Then Pry loose.

If one of these
strips breaks, don’t worry. We’ll cover
how to make a replacement for it later on.
As you remove each plastic piece, take it
off of the tape, and put it in a baggie and
mark it. Once you have removed these
plastic pieces, gently pry the long thin
retainer strip up out of it’s slot, and wipe it
down with some “Goo be Gone” and place
it aside.

You are now ready to remove the Minor
and Major chord button rods. They follow
a similar procedure as just followed in Part 2


Rather than removing the Minor and Major
chord button rods as described above, you
can just remove them as an assembly by
loosening the wooden guide which holds them
as described below. If you choose this method


To remove the wooden guide
which holds the 80 bass button rods. It is
probably held in place by a screw at each
end on the top where the guide slides into a
slot in the wooden “stand off”. Remove
those screws, bag and identify them,
remove the wooden guide, and set it aside.

If you removed it as an assembly with the
bass button rods, lay the assembly on an
old towel and carefully remove the plastic
pieces and retaining strip as described above,
and remove the bass button rods one by one
cleaning them as you do, and placing them in
their correct location in the jig.

Follow a similar procedure for the Bass and
Counterbass button rods. More in Part 4.


  1. Good morning Sir... digiting from Italy... great site and of great help. I have recently removed the bass mechanics (only minor and major rods on a 80 bass accordion) following your detailed infos (thanks for the help... it's the best guidelines I've come across). I now have a small problem since about 10 rods positioned in the middle have been misplaced (my small brother made them fall)... Is there any way I can recover the correct positioning? The first ten rods and the last ten are well positioned... I tried to see if there is a pattern but complicated. If you can help it would be highly appreciated.

  2. For Thomas who is wondering about correct positioning.
    Here is what I would do:
    1. Pick a location which needs to have a bass button rod installed, for example, D7 chord.
    Identify which 3 notes (other than the tonic D) must play to make D7. These would be F#, A, and C.
    2. Now, this may be tricky, but if you only have 10 buttons, it should be OK. Figure out which "fingers" open the F#, A, and C valves. Look at the remaining 10 rods, and try to determine which ones have the Pins sticking out that correspond to those notes.
    That is what I would do.

  3. Thank you very much Tony, your message was of great help!!!! Sorry for my late reply. Things always seem too easy once the solution is at the front of us.
    However I solved the problem with your advice.
    Great updates on the site too.
    Keep well.

  4. Dear Tony,

    I just bought an old accordion to find out that it was actually broken. The problem is that the bass buttons stick. I've opened the side to gain access to the bass button mechanisms and was too scared to do much more than gently lift them beck into position again. I would be willing now, after reading your blog, to take the bass buttons out to try and fix the problem or clean it out... But it seemed to me that the problem was more in the buttons having friction and contact with the holes they stick through. The levers lifted fine, and the buttons pressed and sprung back fine... but if pressed just slightly too low, they would get stuck again. So to me it doesn't seem like a bent wire problem (which I may be wrong about), but like more of a friction-with-wood problem. Would the solution be to either drill the hole slightly larger to avoid so much contact with the button, or to make the button slightly smaller? This may be a horrible solution, but I don't know about accordions either and am just going be what I saw inside. Please tell me if this sounds right or wrong to you, and if wrong- what would you take as the next step in correcting the problem. It's alright if you can't tell with the info I've given. Just thought I'd give it a shot, as I'd love to get this thing working!

    Thank you from Mesa, AZ,