I don't know why, but not many people repair pneumatic equipment. Maybe because they think that pneumatic valves and other staff are not repairable, something that is far from true. I decided to upload this blog entry to show how an expensive pneumatic foot pedal can be repaired with 10 euro spare parts.
Opening the pneumatic valve
You can see the inputs for the hoses on the back side
I unscrewed the 4 screws to remove to cover
It is a very simple construction
The valve is underneath the metallic pedal
The valve is fixed on the pedal with 3 sink screws which i had to remove. Then i went deeper...
3 screws hold the valve onto the base of the pedal.
Each valve has 2 access points, one opposite the other.
I removed the cover from the top access point
And then i removed the cover from the bottom access point
Normally, there has to be a spring somewhere
The piston is then revealed.
Different valves - different pistons
Removing the piston is a tricky part. There are several different types of pistons. Usually, the piston is one fixed piece with rings along its shaft to seal the different areas in the valve. This is the easy to remove piston, because you only have to pull it back with a pair of pliers. But this pedal had another kind of piston, that is also commonly used in pneumatic valves. The piston is composed by 2 pieces which can be screwed together. You can;t remove it from the housing, unless you unscrew it first. Then, you pull the 2 parts with a pair of pliers.
First i had to unscrew it. I used pliers on the left side and a screwdriver on the right
Then i pulled the 2 pieces out of the housing. These are the pieces
Obviously, you see why the foot pedal did not operate. The sealing ring is half...
Repairing the valve
I knew what i was going to find inside and so i was prepared. i already had the spare parts, 2 sealing rings.
These are the 10 euro spare parts, 5 euro each
Replacing the first one was very simple and easy
The second one was kinda hard.
I had to use a small screwdriver for help
Putting it back together
Before i start mounting the valve back, i first had to clean is inside. So i used alcohol to remove the old grease and dirt, and then i applied thin oil
I used kitchen paper and chemicals to clean it
Inside it must be very clean
Then i began mounting it...
This is how the piston will be assembled
But first, a dip of thread glue
I screwed the two parts with a pair of pliers and a screwdriver
I put the spring back in place
And covered it with the first cover
Then i fixed the valve back onto the foot pedal base
I put the top cover
And finally i put the spring.
Then i placed the cover and tested the equipment. It works perfectly fine. So, next time that a valve fails, before throwing it away try to repair it...
a very interesting project,which i have just found myself having to do.
the only problem is i can not find a supplier for the sealing rings.
i would be ever so grateful if you could let me know where you got yours from, as they are the exact ones i need.
many thanks for your blog.