GTO 46 Paper feed won't stop

Hi all,

Posted this a couple of weeks ago and thought I had it resolved, but alas it is not so.
My feeder suction won't switch off.
We have replaced the limit switch under the feed board but still no different. Also disassembled the manifold on the front of the pump and cleaned out 50 years of paper dust.

Any thoughts appreciated.
Thanks in advance.

 

hi dear sir make sure to check the function of the part when you press the stopper. see the picture sent to you thank you very much.

 

First, check “sniff piston” above drive motor. (You don’t have holes in traveling feed gripper covered with tape, do you?). If sniff piston is operating properly, remove DS cover and check that solenoid operating on/off of vacuum is not blocking vacuum relief port when not wanting to feed sheets.

 

Silly to mention but did someone turn on the switch on front of press for manual feed without impression
On my 52 it’s on left side of feeder

 

Unfortunately I wish it was that simple.
Certainly not silly to mention. A failure in that switch would produce EXACTLY the same fault I'm currently dealing with.

 

Thanks Junker.
Sniff piston appears fine and switch it activates has been replaced.
Is there anything I should know before attempting to remove the drive side cover?
Knowing Heidelberg I suspect it's not 3 bolts and a tap with a hammer.............

 

Before you pull DS cover, are you seeing sniff piston plunger moving in/out while not feeding sheets? If you see it moving, is it possible the switch lever has been bent away from plunger? Have you homed out the switch to be sure it's working? While press is idling, can you manually trigger switch to stop sheets from feeding?

 

Travis, The switch lever on sniff piston would have to be stuck in "closed" position in order to continue feeding sheets...I mentioned otherwise. As to pulling off DS cover of feeder, it's pretty straightforward.