Air leak from treble side?

[Bloviator]

I have a relatively new accordion that is leaking enough air to interfere with playing. If I drop the bellows from full extension, it takes about 3 seconds to close and some notes sound on the treble side. Which notes seems to depend on what register is selected.

The gasket seal is intact and pliable with a tight fit on both sides. Pins are tight.
The base side valves and blocks are in good condition. Covering the holes with paper made no difference.
On the treble side again the valves are fresh, but I did not take the blocks out.
Under the grill it appears there is good contact with the pallets and a paper drags on all corners.

I can hear the faint sound of air leaking, but when I get close to the locations I have mentioned, it seems to not originate from there.

Are there other easy locations to look in? I lack a lapel mic and a stethoscope as is suggested elsewhere.

 

[debra]

There are several methods to find out which of the pallets do not close properly (and thus cause air loss and notes that play on push without pressing any keys.
1) remove the reed blocks, select the master register and close blinds and dim the lights in the room. Then shine a light from inside to outside, moving around and while you do that, watch closely whether you see light appear around the pallets. If light gets through then the leather (from the felt+leather on the pallets) isn't sealing in that location.
2) similarly, remove the reed blocks, select the master register and close blinds and dim the lights in the room. Then shine a light from outside to inside, moving around and while you do that, watch closely whether you see any light on the inside. if light gets through to the inside then there is an air leak where the light is.
3) Press a key to open the pallet. Place a cigarette paper under the pallet, let go of the key (close the pallet) and feel how much force is needed to pull out the paper. Where it is easiest to pull out the paper the pallet is not pushing down enough.
Once you have identified where the leaks are it becomes a matter to adjust the key levers (metal arm going from key to pallet) so the pallet is positioned correctly over the holes and presses down evenly on both ends. The tools to safely bend the "arms" a bit are called "torciferri". If the connection between the arms and pallets is with wax you can also heat the wax a bit and press down where the pallet needs to push down more. A tiny adjustment is usually all that's needed.

 

[jollyrogeraccordions]

My 'go to' diagnostic tool for air leak detection is a stethoscope with the diaphragm removed. The tube end is then ranged over suspect area and you will pretty quickly find the source of any leak. You can get a cheap stethoscope from eBay (about £5 in the UK).
If a there is a leaky pallet i normally remove it, check the leather, then reset it flat with some wax (if it is fixed on rather than floating on a rubber mount). I generally ream out the channel on tthe pallet to ensure the arm doesn’t grip on old wax and reintroduce any pallet fondo misalignment. This takes very little time and is a minimal intervention.
If the keys are already level and you can get at and remove a pallet, I would not bend the lever arm to fix leaks. If you bend a lever arm (normally to flatten a wonky keyboard) the pallets mostly need removing and resetting flat. Any bend in the lever alters the geometry and misaligns the pallet and the fondo.
Sometimes air leaks are caused by something getting caught on the leather facing. You can check for this in step 1) of Debra's solution, by inspecting the leather facing through the fondo holes after removing the reed blocks.

 

[Bloviator]

My 'go to' diagnostic tool for air leak detection is a stethoscope with the diaphragm removed. The tube end is then ranged over suspect area and you will pretty quickly find the source of any leak. You can get a cheap stethoscope from eBay (about £5 in the UK).
If a there is a leaky pallet i normally remove it, check the leather, then reset it flat with some wax (if it is fixed on rather than floating on a rubber mount). I generally ream out the channel on tthe pallet to ensure the arm doesn’t grip on old wax and reintroduce any pallet fondo misalignment. This takes very little time and is a minimal intervention.
If the keys are already level and you can get at and remove a pallet, I would not bend the lever arm to fix leaks. If you bend a lever arm (normally to flatten a wonky keyboard) the pallets mostly need removing and resetting flat. Any bend in the lever alters the geometry and misaligns the pallet and the fondo.
Sometimes air leaks are caused by something getting caught on the leather facing. You can check for this in step 1) of Debra's solution, by inspecting the leather facing through the fondo holes after removing the reed blocks.

I may have to acquire a stethoscope.

The light trick worked well for the MM reeds, but I was unable to access the pallets for the tone chamber. The plate that holds the secondary tone chamber did not give me a lot of clues on how to remove it.
It seems very firmly attached after removing the screws.

Any tips on how to get it out?

 

[Bloviator]

There are several methods to find out which of the pallets do not close properly (and thus cause air loss and notes that play on push without pressing any keys.
1) remove the reed blocks, select the master register and close blinds and dim the lights in the room. Then shine a light from inside to outside, moving around and while you do that, watch closely whether you see light appear around the pallets. If light gets through then the leather (from the felt+leather on the pallets) isn't sealing in that location.
2) similarly, remove the reed blocks, select the master register and close blinds and dim the lights in the room. Then shine a light from outside to inside, moving around and while you do that, watch closely whether you see any light on the inside. if light gets through to the inside then there is an air leak where the light is.
3) Press a key to open the pallet. Place a cigarette paper under the pallet, let go of the key (close the pallet) and feel how much force is needed to pull out the paper. Where it is easiest to pull out the paper the pallet is not pushing down enough.
Once you have identified where the leaks are it becomes a matter to adjust the key levers (metal arm going from key to pallet) so the pallet is positioned correctly over the holes and presses down evenly on both ends. The tools to safely bend the "arms" a bit are called "torciferri". If the connection between the arms and pallets is with wax you can also heat the wax a bit and press down where the pallet needs to push down more. A tiny adjustment is usually all that's needed.

On inspection I can see light coming from all of the pallets in the first row through the amplisound holes. None of the pallets outside the tone chamber show light.

Still no luck removing the plate. The amplisound switch is well out of reach beneath the keyboard and I hope it is not secured from that side.

 

[debra]

On inspection I can see light coming from all of the pallets in the first row through the amplisound holes. None of the pallets outside the tone chamber show light.

Still no luck removing the plate. The amplisound switch is well out of reach beneath the keyboard and I hope it is not secured from that side.

Not sure what you are looking at.
On an accordion with amplisound you should remove the amplisound box to get access to the reed blocks to take them out.
When you have removed the reed blocks, shine a light from the outside in the cassotto and see if you can see light coming through the holes covered by the leather part of the pallets. Or shine a light onto the holes for the notes inside the cassotto and see if any light comes through to the outside.
The amplisound part is not involved in this bit of testing at all.

 

[jollyrogeraccordions]

OK, tone chamber (fx..klaxon sounds, red light flashes). I mentioned removing pallets "if you can get at [the pallet]”, because air leaks inside a tone chamber can be tricky to resolve and I was mindful of the extra difficulties. It sounds like you have a diagnosis. I'm interested if someone else on here knows how to get at/reset/reface etc pallets inside a tone chamber. A while ago I was in conversation with Emilio Allodi (of London) and we agreed that tone chambers can be a pain.

 

[debra]

OK, tone chamber (fx..klaxon sounds, red light flashes). I mentioned removing pallets "if you can get at [the pallet]”, because air leaks inside a tone chamber can be tricky to resolve and I was mindful of the extra difficulties. It sounds like you have a diagnosis. I'm interested if someone else on here knows how to get at/reset/reface etc pallets inside a tone chamber. A while ago I was in conversation with Emilio Allodi (of London) and we agreed that tone chambers can be a pain.

I agree that tone chambers are a pain for accordion repairers. But the OP mentioned "amplisound" and that is a double pain because to get at the treble reed blocks you have to remove the amplisound chamber (and later put it back).
I find that to get at the pallets inside a tone chamber there is essentially no way around just disassembling the keyboard completely. That's relatively easy on a PA but is a really pain on a CBA. (And just my luck that my wife and I both play CBA..., and our latest CBA is one from just over 10 years ago, a short period where many accordions that were built then develop a "sticky pallet" problem after several years)

 

[Bloviator]

OK, tone chamber (fx..klaxon sounds, red light flashes). I mentioned removing pallets "if you can get at [the pallet]”, because air leaks inside a tone chamber can be tricky to resolve and I was mindful of the extra difficulties. It sounds like you have a diagnosis. I'm interested if someone else on here knows how to get at/reset/reface etc pallets inside a tone chamber. A while ago I was in conversation with Emilio Allodi (of London) and we agreed that tone chambers can be a pain.

I was able to get past that plate that has the holes for the amplisound chamber. It was part waxed part stray glue that was holding it up.

All of these are loose and have more play then the ones outside the tone chamber. Is the course of action to extract the keyboard and replace all of these with a thicker felt to make them tighter.

I also notice that the lowest reeds that are deepest in the tone chamber have a hole in them. Any ideas what the function of putting a hole in there would be?

 

[jollyrogeraccordions]

..yes tone chamber coupled with leaky pallets and a CBA keyboard is especially time consuming to fix. I have to admit I refuse to work on them.

 

[Bloviator]

..yes tone chamber coupled with leaky pallets and a CBA keyboard is especially time consuming to fix. I have to admit I refuse to work on them.

I think the problem is beyond my ability. It does not make sense to me why all of the pallet arms should be loose / exert less pressure compared to the non tone chamber arms.
The reed blocks push up against the wall very tightly so It seems unlikely that the wall itself could have moved away from the pallets. And the entire armature assembly seems to be secured in a way that would make it very difficult to shift upwards away from the wall while still secured.