I'm trying to repair an old piano and I've never done this before. I've identified several problems:

  • Bridle strap broken on one key
  • Jack spring missing on two keys
  • Bridle strap too long on one key*
  • Jack missing entirely on one key, along with jack spring
  • Hammer missing entirely on one key
  • Jack keeps getting stuck under/behind the "hammer butt felt" on one key, this key's bridle strap is also too long.**
  • Deep grooves have been worn into the hammers where they strike the strings
  • Sustain pedal horizontal lever barely attached to vertical component using tape...not sure how best to establish a firm and tight connection, but can be figured out.
  • Sustain pedal clacks against tile floor when depressed because it's either positioned too low, allowed too much range of motion, or some form of padding is missing. Not sure what is supposed to prevent that.

I believe I can fix most or all of these problems, but I'm not sure if I can just get generic components or if I have to find ones specific to this piano. That's the primary question.

I also have yet to figure out how I can remove an individual wippen/jack/hammer from the action rack for servicing, but hopefully with google I can figure that out. Certainly there's no way to get the jack in for the missing one without removing it from the rack. So if anyone knows good resources on this, that's the secondary question. No idea how to attach a new bridle strap to the hammer. Subtle application of glue?

Lastly, my understanding is that sanding down the hammers can be risky if the grooves are very deep, since it can affect the piano's "geometry" and cause there to be too much distance between the hammers and the strings. Opinions? I didn't think to get a picture of the state of the hammers; I can update with that later.

If anyone has any general advice or good resources on any of the mentioned necessary repairs or how and where to get parts, that'd be great. Thanks!

*I fixed this temporarily by unhooking the bridle strap, pulling it taught, and repuncturing it-- however it was past the red leather bit at the end; I had to puncture the white strap itself to make it taught and get it in line with the other wippens' positions. I assume this hugely facilitates wear on the strap, but as I said it was a temporary fix.

**#16 in this diagram, if you need to look up "hammer butt felt" as I had to do. It's right near the center under #17.

1 Answer 1


In England, most piano actions were made by a different company from the one on the piano's nameplate. One of the oldest and largest companies was Herrburger Brooks, which also operated in France until the 1950s. The company went into receivership in 1998, but there are so many of their actions in use that spare parts should still be available.

if you remove the action frame from the piano, you will probably find the maker's stamp and the model number somewhere on it (often stamped in ink direct onto the wood, not a separate plate).

The action is unlikely to be unique to that particular model of piano, but (obviously) the action manufacturers made a wide range of different actions, designed to work with different shapes and sizes of the cast iron piano frames and the different stringing arrangements.

Basically, you need to identify the maker and model number of the action - either by reading any markings on the action itself, or starting from the serial number of the piano (which will probably be marked somewhere inside the case) or the cast iron frame.

I also have yet to figure out how I can remove an individual wippen/jack/hammer from the action rack for servicing

Usually, the complete action for each note is attached to the frame by wooden joint that locates its position precisely, and fixed by a single screw. First take the action frame out of the piano, then remove the action for the note that needs repairing. You will then be able to see how to take the action apart. You may need to press the metal pins out of the bearings to remove some of the parts - you can't do that while the action is still attached to the frame.

If there are several notes with "randomly" damaged items, it is likely that everything in the action is on its way to being worn out. In that case, getting a complete replacement action frame may be the best (and quickest) way to do a repair job that will last a long time, though obviously it will be more expensive than fixing up the bare minimum number of damaged parts.

Repairing the pedal mechanism is usually a matter of using mechanical common sense (1) to figure out what's wrong with it, and (2) to fix it.

  • A general tip for this sort of work: Make sure you keep a record of exactly where all the parts came from, and don't assume that "identical" parts (or even "identical" screws, etc) really are identical, especially on an old instrument. They may not have been manufactured to the same mass-produced close tolerances as modern screws, and you don't want to end up with something left slightly loose, after fitting a slightly under-sized screw in a slightly over-sized hole - and then stripping the threads that the screw has cut in the wooden hole while trying to tighten it.
    – user19146
    Commented Aug 21, 2016 at 4:04
  • The point about screws is especially important. Wood screws were often made without any particular attention to whether their threads matched those of any other screws in the universe. If one screw has nine threads/inch and another has ten, putting the former screw in a hole that had previously held the latter will chew up the wood where the threads had been.
    – supercat
    Commented Aug 31, 2018 at 21:49

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.