Removing Valox valve guides
Many 1970’s era Olds trumpets and cornets have “Valox” or plastic valve spring barrels and guides. This is what the valve piston assembly looks like:
At first glance, there does not seem to be any way to disassemble the valve spring barrel, but once you see how it is done, it is quite simple. If your valve guide is worn or damaged, it may be hard to locate a replacement, but the bigger issue is how to replace the springs, which can be done without much effort.
First, unscrew the finger button from the valve stem. This will allow the top cap to be removed as well.
The next step is to remove the felt that is on top of the spring barrel
The metal connection at the bottom of the valve stem looks to be some type of spring clip, but this is not the case. The valve stem simply unscrews from the spring barrel. The hard part is finding a suitable grip on the valve stem without causing damage.
Once the valve stem is unscrewed, the spring barrel can be gently pulled straight out from the top of the piston.
This releases the spring and the valve guide.
There is a pin in the bottom of the valve guide which inserts into the top of the piston for the correct alignment
Reassembly is by placing the spring over the spring barrel and placing the valve guide at the bottom and then inserting the spring barrel into the slot in the piston. Then the valve stem is screwed back into the spring barrel. The felt is then placed on then valve stem followed by the top cap and finger button.