This is the inside of the first valve casing of a Yamaha YHR-314 student model single French Horn in F. As you can see it has been marred.
Here are the three main components of this replacement: The marred valve casing at the left, the rotary valve(also marred) at center and the bearing plate at right.
This is the new assembly to replaced the damaged part. $202.78 straight from the manufacturer.
First, I have to remove key cradle bar. It's needs to be out of the way.
Next, I remove the bumper plate from the damaged casing
Next, I proceed with the removal of the first rotor outer tubes. With a permanent marker, I label each with L and R to ensure that they are properly positioned at reassembly. I use a tube expander to grip the tube's inner diameter and safely maneuver it from it's fixed position as I warm the soldier joints with the torch.
Here, I removed the connecting cross braces.
Both first tuning slide outer tubes have been removed.
Now it's time to remove the damaged first casing. I again use a tube expander to grip a knuckle of the casing.
And, it's off!
Here, I am using a steel slide mandrel to round a connecting knuckle from the second valve casing. This has to be done to ensure that the new first valve casing being installed inserts easily into the knuckle.
In with the new!
Reassembly with new first valve casing.
I've inserted the first valve tuning slide to help with proper placement and alignment of the tubes and new casing.
This is the new assembly after cleaning off some of the heat varnish at the buffer wheel in the buffer room.
As I do more of this, I will learn how better to control the heat from the torch and hopefully not create so much varnish in the disassembly/reassembly processes. In order to take off as much varnish as I can, I decided to use a dremel tool fitted with a small buffing wheel and some Tripoli buffing compound.
There! That's better.
After dent removal and another trip to the sonic cleaner, four hours later she's finished.
The proof is in the playing!
All good!
Into the case and out into a store for rental somewhere in America.
