When is a Thayer too leaky
- marcklim
- Posts: 1
- Joined: Apr 03, 2025
I play an early Shires large bore tenor (bought it almost 2 decades ago 2nd hand) that has an OE Thayer valve on it. Seems like a pretty old valve, the Serial number on the valve is 00228 and it certainly has some milage on it, there is wear on the internal cone (which seems to be plated brass).
After watching Aidan's video on "The Thayer problem", I checked the end play and noticed some. The horn also plays better with the valve well oiled. Other than playing characteristics, are there any other ways to check for leakiness of the valve? Is it worth taking the valve to a tech or considering replacing the cone, valve or entire section?
After watching Aidan's video on "The Thayer problem", I checked the end play and noticed some. The horn also plays better with the valve well oiled. Other than playing characteristics, are there any other ways to check for leakiness of the valve? Is it worth taking the valve to a tech or considering replacing the cone, valve or entire section?
- elmsandr
- Posts: 1373
- Joined: Mar 23, 2018
Yeah, it is worth it to have it properly adjusted and fit so that there is not excessive play or leaks. You will be amused by how different it can be when not leaking.
Replacing the cone can be done…. Depending. That’s real in the weeds to getting them fit right, however. Note that decent fitting can be done by a lot of people, but definitely not everybody. Make sure they know and have done the work before.
Cheers,
Andy
Replacing the cone can be done…. Depending. That’s real in the weeds to getting them fit right, however. Note that decent fitting can be done by a lot of people, but definitely not everybody. Make sure they know and have done the work before.
Cheers,
Andy
- Nomsis
- Posts: 149
- Joined: Feb 02, 2022
Without engaging the valve you can pull your tuning slide. The tighter it is the longer it can contain the pressure difference. So if you pull it by a few centimetres and you can hear the pressure equalizing immediately it is pretty bad. It is normal that some air can go trough and you can hear this but it should hold for quite a few seconds at least before pressure has euqalized, better longer. You can test your vacuum after a few seconds by engaging your valve, the louder of a pop you can hear the better. Of course you can do this in the opposite way as well by pushing in the slide. Trumpet players do the pop test by pulling the slide completely and listening to the pop when removing the slide but I think you can learn more about your valve the way I have described it, because almost every valve will pop when pulling the slide fast enough.
- CalgaryTbone
- Posts: 1460
- Joined: May 10, 2018
Edwards has a machine in their shop that measures how much air pressure your valve is holding (there's probably a better way of describing that). Anyway, mine was leaking badly when I brought it to the shop. They ended up replacing the entire valve (keeping the same tubing - just a new valve and casing).
The problem is that it happens very slowly, so after it gets to a certain point, it starts to feel like your chops are out of shape - things take more effort. Most of us will just keep working harder and think we need to practice more (not entirely a bad thing, but not optimal either).
I would suggest checking with Edwards - I can't speak for them as to what the price is, but I remember it being a very reasonable cost and they did the work in the couple of days that I was in town. You can probably just send them the valve section and they can fix it and send it back to you. Mine ended up not being re-lacquered since that would have required more time.
Jim Scott
The problem is that it happens very slowly, so after it gets to a certain point, it starts to feel like your chops are out of shape - things take more effort. Most of us will just keep working harder and think we need to practice more (not entirely a bad thing, but not optimal either).
I would suggest checking with Edwards - I can't speak for them as to what the price is, but I remember it being a very reasonable cost and they did the work in the couple of days that I was in town. You can probably just send them the valve section and they can fix it and send it back to you. Mine ended up not being re-lacquered since that would have required more time.
Jim Scott
- GabrielRice
- Posts: 1496
- Joined: Mar 23, 2018
As Jim describes, a leaky Thayer valve will drive you slowly insane.
I have a student right now with an Infinity valve Bach 42B. She makes great sounds with the characteristic Bach balance of body and ring, but tended to have problems with accuracy - and not just in the high register. I had a hunch and played it, finding that I had the same problems. It didn't really feel leaky or uncentered in the way some bass trombones I've played with leaky Thayers did, but I would try to play a middle C or Eb above it and miss for no apparent reason.
She brought it to Lou Anderson, the fantastic tech at Virtuosity in Boston, who tightened it up and made it play MUCH better.
A couple of weeks later I noticed that it was moving very slowly. I took it apart, wiped it down, oiled it thoroughly, and - voila! I'll see her later today and check on it.
I had another student with a Getzen axial bass trombone that he completely wore out. I mean completely. It had so little compression I couldn't find the center of any pitch in any register. And then another student a few years later with an Edwards the same way. I don't blame Getzen/Edwards; I've played examples of both that are fantastic. There is so much bearing surface on axial valves that they are very prone to this kind of wear. They both practiced A LOT and didn't oil their valves nearly often enough.
I urge everyone with axial valves to oil them at least every other day and bring them in to a qualified tech for regular service at least once a year.
I have a student right now with an Infinity valve Bach 42B. She makes great sounds with the characteristic Bach balance of body and ring, but tended to have problems with accuracy - and not just in the high register. I had a hunch and played it, finding that I had the same problems. It didn't really feel leaky or uncentered in the way some bass trombones I've played with leaky Thayers did, but I would try to play a middle C or Eb above it and miss for no apparent reason.
She brought it to Lou Anderson, the fantastic tech at Virtuosity in Boston, who tightened it up and made it play MUCH better.
A couple of weeks later I noticed that it was moving very slowly. I took it apart, wiped it down, oiled it thoroughly, and - voila! I'll see her later today and check on it.
I had another student with a Getzen axial bass trombone that he completely wore out. I mean completely. It had so little compression I couldn't find the center of any pitch in any register. And then another student a few years later with an Edwards the same way. I don't blame Getzen/Edwards; I've played examples of both that are fantastic. There is so much bearing surface on axial valves that they are very prone to this kind of wear. They both practiced A LOT and didn't oil their valves nearly often enough.
I urge everyone with axial valves to oil them at least every other day and bring them in to a qualified tech for regular service at least once a year.
- GabrielRice
- Posts: 1496
- Joined: Mar 23, 2018
To the OP: if I were you I would look to replace the entire valve section.
This might open a can of worms, but it's all things that can be dealt with. The earliest Shires matched Bach threads between the slide and valve section, but they changed that at some point. The tenon on the slide can be easily replaced to match current production. You will probably need to have the fitting of the bell to the valve section adjusted a bit too - again, not that difficult.
The bigger issue will be that the instrument will probably feel tight to you when you get all that changed. Stick with it...you will get used to it, and everything will ultimately respond better.
This might open a can of worms, but it's all things that can be dealt with. The earliest Shires matched Bach threads between the slide and valve section, but they changed that at some point. The tenon on the slide can be easily replaced to match current production. You will probably need to have the fitting of the bell to the valve section adjusted a bit too - again, not that difficult.
The bigger issue will be that the instrument will probably feel tight to you when you get all that changed. Stick with it...you will get used to it, and everything will ultimately respond better.
- mklimaschewski
- Posts: 4
- Joined: Oct 26, 2025
Thanks for the input. I did the test that Nomsis described and listed for pressure equalizing as well as the amount of pop when triggering the valve. Seems like this Thayer for sure is leaky.
I totally agree with CalgaryTbone, this is a tricky issue because it's hard to tell what the horn *should* sound like. A couple years ago, I had a chance to try a section mate's Shires with a rotor valve which played differently but I concluded that what I am feeling is "just the way Thayers are"...
Time to have a pro take a look, would be pretty cool to sound better and have a better playing horn by just fixing an issue with the hardware.
I totally agree with CalgaryTbone, this is a tricky issue because it's hard to tell what the horn *should* sound like. A couple years ago, I had a chance to try a section mate's Shires with a rotor valve which played differently but I concluded that what I am feeling is "just the way Thayers are"...
Time to have a pro take a look, would be pretty cool to sound better and have a better playing horn by just fixing an issue with the hardware.
- Burgerbob
- Posts: 6327
- Joined: Apr 23, 2018
As said above, it's easy to normalize how a leaky valve plays and get used to it. But boy howdy is your life better when it seals. It's worth the work.
- Posaunus
- Posts: 5018
- Joined: Mar 23, 2018
Just make sure that your tech is familiar with Thayers!
Not all techs are equal.
Not all techs are equal.
- CalgaryTbone
- Posts: 1460
- Joined: May 10, 2018
My section noticed immediately when I got back from Elkhorn with the Thayer fixed. More core in the sound, and better louds and softs. Better accuracy for sure. I don't remember exactly what Cristan told me about the measurements from their machine, but mine was down to something like 1/2 a pound of air pressure, when they want to see 1 pound to 1.5 pounds.
I heard second-hand, that part of the reason that Joe Alessi moved away from Thayers is that he had a similar issue with his. They are good valves when they are adjusted properly. I second the warning that not all techs are up to speed on the ins and outs of Thayer valves. In Canada, we used to have Ron Partch who Shires would recommend for working on their horns. He retired and closed his shop, so it's a lot more difficult to get some of those high-end repairs these days.
Jim Scott
I heard second-hand, that part of the reason that Joe Alessi moved away from Thayers is that he had a similar issue with his. They are good valves when they are adjusted properly. I second the warning that not all techs are up to speed on the ins and outs of Thayer valves. In Canada, we used to have Ron Partch who Shires would recommend for working on their horns. He retired and closed his shop, so it's a lot more difficult to get some of those high-end repairs these days.
Jim Scott
- Lhbone
- Posts: 372
- Joined: Sep 01, 2019
Todd Clontz owns O.E. Thayer now. He offers rebuilding as a part of his advertised services.
https://thayervalve.us
https://thayervalve.us
- dougm
- Posts: 34
- Joined: Jan 08, 2020
I was told by the folks at Edwards that they were looking for the axial flow valves to hold 2 psi on their test fixture.
Doug
Doug
- CalgaryTbone
- Posts: 1460
- Joined: May 10, 2018
[quote="dougm"]I was told by the folks at Edwards that they were looking for the axial flow valves to hold 2 psi on their test fixture.
Doug[/quote]
That's possible - it was a while ago that I was there, and I could be off on the numbers. I just remember that they were not happy with where my valve was measuring before the repair job.
JS
Doug[/quote]
That's possible - it was a while ago that I was there, and I could be off on the numbers. I just remember that they were not happy with where my valve was measuring before the repair job.
JS
- Blabberbucket
- Posts: 305
- Joined: Oct 09, 2022
Axial valves are inherently flawed and prone to leaking based on their design. The main thru-port (the tip of the cone) is one of the bearings of the valve. The spindle and bearing plate opposite the cone, and the cone itself, require precise fitting for the valve to seal well. As the tip of the cone wears over time, as bearings will do, the cone itself will continue to seal well but the flat bearing will develop end play and begin to leak.
Rectifying this requires either replacing the original valve body and refitting a new one to the existing casing, or refitting the existing bearing plate to remove the end play which requires rebuilding the valve section.
Rectifying this requires either replacing the original valve body and refitting a new one to the existing casing, or refitting the existing bearing plate to remove the end play which requires rebuilding the valve section.