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Part 6b: S Series
Door adjustments and fine tuning continued
Note: Only for S series operators
C. Door Slows too Soon When Closing:
1.Locate the airflow control screw on the bottom of the down cylinder (closest to the wall).
2.Turn the airflow control screw one complete turn counter clockwise or until the door operates properly
Note: Use caution: Unscrewing too far will cause it to come out. When screwing it back in, pay attention to the two holes adjacent to each other on the bottom cap. Placing the screw in the wrong hole causes the loss of the cushioning effect. The correct hole has threads.
D. Door Closes too Quickly (Slams Into Floor):
1.Locate the airflow control screw on the bottom of the down cylinder (closest to the wall).
2.Turn the airflow control screw one complete turn clockwise or until the door operates properly.
E. Door Goes Up Slowly and Comes Down Rapidly:
1.Check the door spring torsion. The springs may need tightening or may be broken. If you have counterweights, make sure that they are properly balanced and weighted.
2.If the springs are fine and the door is properly balanced, check the breather vent on the bottom of the air cylinders. The ball on top of the breather vent should be free to float with the air flow and the vent should be clean.
F. Door is Jerky or Needs a Boost to Get Started:
1.Check the door itself. Make certain the rollers, track and torsion springs are lubricated and not binding. If you have counterweights, make sure that they are balanced. Also check the bottom of the operator for air leaks. When the door is stationary, you should not hear air leaking.
G. Door Goes Partway and Stops:
1.Check for air leaking from the bottom of the cylinder. A stationary door should not have any air leaking from it.
2.If air is leaking, the piston needs new seals. Call UPI at
3.If there is no air leaking, check the collars that hold the chain/belt to the piston rod, or the sprocket that connects the chain/belt to the door shaft. One or the other may be slipping.
4.Check the door for binding.
5.Check the tension shaft bearings to see if they are working.
6.Check the needle valves to make sure they are not too tight.
H .Door Goes Up and Down Slowly:
1.On the bottom cap of the cylinder, there is a breather vent screwed into the cap. This allows air into the cylinder when the piston is moving upwards. The breather vent has a small check ball floating above it. If the check ball sticks or the breather vent gets clogged, the operator will not function properly. It may operate slower than usual, stop partway, or slam when opening or closing. Use a 7/16” wrench to remove the breather vent. Make certain the ball is
