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Backplate stuck on rotary valve
Posted: Sat May 18, 2013 5:27 pm
by chronolith
Anyone have advice on how to unstick a backplate from a recently removed rotary valve? I got the valve out with no problems but I cannot get the backplate off of the valve. As it is the valve does not function.
Any advice would be very welcome. And yes, I have a performance tomorrow that is depending on this horn.
Re: Backplate stuck on rotary valve
Posted: Sat May 18, 2013 6:36 pm
by Tubaman2365
I'm not a repair person. However, you might try some penetrating oil on it. That might loosen it up to remove it.
Re: Backplate stuck on rotary valve
Posted: Sat May 18, 2013 7:35 pm
by chronolith
Problem is the plate and valve are damn hard to get a good grip on. I ended up standing the valve in a cup with the backplate on top, dabbing some oil on the center where the plate and the spindle intersect, and leaving it for about 30 minutes. Came back with some tacky gloves and was able to get them apart without too much drama (or further injuring myself).
Scrubbed out the crud with toothpaste and washed out the casing and the valve in warm water. Put it back together and back in business.
Was a heck of an "oh $#!%" moment and I don't want to repeat it.
Re: Backplate stuck on rotary valve
Posted: Sat May 18, 2013 10:33 pm
by Dan Schultz
Whoa.... please clarify:
- Did the rotor come out with the backplate stuck on the bearing?
or
- is the backplate stuck in the rotor housing? If so... how did you get the rotor out?
Re: Backplate stuck on rotary valve
Posted: Mon May 20, 2013 10:13 am
by chronolith
I was able to push the valve itself (and the backplate attached to the valve) out of the casing with no trouble. I just had a hell of a time separating the two once I got them out.
I generally trust all of my valve work to pros since moving to rotary horns a couple of years back. In this case I had to get in and get the job done myself. This is was the first time I ever had to completely remove a valve myself. I know a heck of a lot more about rotary valves than I used to, that's for sure. Jeff Funderburk's Youtube videos were very helpful.
Question to the crowd: Can anyone recommend a good kit to keep handy with all of the proper tools for doing emergency maintenance? One post turned up in a search recommending a specifically small rawhide mallet. What else do I need? Does anyone sell such a kit?
Re: Backplate stuck on rotary valve
Posted: Mon May 20, 2013 10:25 am
by Dan Schultz
chronolith wrote:I was able to push the valve itself (and the backplate attached to the valve) out of the casing with no trouble. I just had a hell of a time separating the two once I got them out.....
OK... I see. It's a bit unusual for the backplate bearing to freeze to the rotor spindle. That's a good argument to unscrewing the back caps every month or so and putting a drop of oil on the rear spindle.
I can normally accomplish all the rotor work with a small screwdriver (NOT used as a prybar), and a small rawhide or plastic mallet. Sometimes a short piece of 3/16" brass rod to separate the stop arm from the rotor is helpful.
The really nice thing about rotors is.... properly oiled and maintained, they seldom cause any problems of an emergency nature.
Re: Backplate stuck on rotary valve
Posted: Mon May 20, 2013 11:13 am
by chronolith
Actually I was oiling up the backplate when it all went wrong on me. I generally get in there every few weeks to do this, but this time was different. Also, when I replaced all the parts after scrubbing them out I had the problem repeat itself but not quite as bad. I could turn the valve by the stop are but not with the thumb handle. Took everything out again and specifically scrubbed out the points where the backplate touches the casing. I had a feeling the there was something in there not attached to a moving part but forcing the backplate slightly out of alignment and torquing the valve. Since then it is like new.
Thanks for the tool tips. Going to do some shopping today.