new contact rollers shorting out!

Perhaps post a photo or two? I assume you insulated the roller assembly from the truck frame, including the screw.

How are the springs that hold the rollers down.  I usually replace them since they weaken or corrode over time and loose their spring.  Then the roller assembly slops around and shorts out.

This is one with a new spring.     They are not strong to begin with.           

What may be happening is when the pick-up assembly is installed on the truck, the pick up rivet may be touching the inside of the truck. If the tender was handled rough, it bends down the truck frame and shorts on the rivet. Either add a piece of electrical tape on the truck frame, or straighten the truck frame so the rivet has clearence.

I will take the trucks off the tender and see what I can do. One thing I did to help with the rivet for the roller assembly was to use Zap a Gap to hold the pin in place so I could get it all assembled. Is this Zap a Gap conducting electricity??  I have an old pair of trucks with worn out rollers,  I didn't notice any material to prevent conducting electricity to make a short.

@Ken Wing posted:

Perhaps post a photo or two? I assume you insulated the roller assembly from the truck frame, including the screw.

I assume when you say screw, you mean the rivet?!

No, I meant screw. Absent a photo of your situation, I imagined mine, adding pickup rollers where none had been before. These are a flat plate about half-inch square with a spring-loaded roller bracket angling off one end, similar to many loco pickups, and a screw hole in the center of the plate. In some cases, the screw holding the new roller assembly was tapped into electrically grounded metal; therefore it had to be insulated from the roller assembly itself. From the other posts, it appears your roller assembly is attached differently.

My roller assemblies are riveted in place. What I did to help get the rivet in place through the hole etc. I gave it a tab of Zap A Gap to hold it so I could assemble it into the truck. I will get pictures today once I get downstairs. Thanks.

It appears by putting in some electrical tape I have insulated it so there is no short. However now I can't get the unit to whistle and I am wondering if this new roller assembly isn't sticking out far enough to make good contact with the rail. I see this because when I push down on the frame especially to one side, I get contact and the whistle blows. Any ideas. I will insert some photos.

It appears to me roller does not stick down far enough to the rail. Ideally, it protrudes somewhat beyond the wheel tread. It also appears to be at an angle. Can't tell from the photos why. Wondering if maybe some flash is interfering with the roller's movement?

I am not overly happy with these repro parts. ANd I will have to wait until I can order more to re-do everything, and see if I can make a difference. These are tricky with my shaky hands, which is why I used zap a gap to hold the rivets in place.

The rivet securing the pickup has to be tight, using the proper rivet tool is a must.  If not tight, the the loose bracket will cause the spring rivet to contact the tab on the truck.  Also, if the pickup assembly is not assembled correctly, if the rivet securing the bracket and spring is too tall, it will short on the tab on the truck.

Here is how they look on this old tender.  The roller does not extend above the flange, but is definitely higher than than the tread.  The other pic shows how close the rivet is to the frame, make sure there is not enough slop that it is contacting the frame.