Vending Machines

[channelmaniac]

Model: NRI 8-56-007 Coin Accepter
Symptom: Would not activate vending solenoid. Would not count coins or give change.

The unit was out of an old Vendo 154 Dr. Pepper machine and all of the old lubricant had turned to gum. Fully degreased unit and lubricated select parts to fix.

To clean/degrease I used brake cleaner. TEST BEFORE USING as some types eat plastic.
To lube I used Shooter's Grease from Brownell's.

Detailed steps:

1. Remove the coin accept/reject mechanism by lifting up on the triangle tabs and tilting it downward.

Clean by soaking for 10 minutes in boiling water. Yes... that's what they said in the manual for the older model coin mechs whose manuals I could find. However, I used brake cleaner.

Only lube the pivoting weights with graphite. DO NOT OIL.

Check coin paths to make sure they are smooth. If not, use some steel wool or scrub pads to clean. Use soap/water only. Dry well. I used a hair dryer to speed drying.

Set it to the side.

2. Disassemble the remaining coin mech as best you can. Start with the coin reject paths down the left side. Two screws hold the middle piece on and two hold the bottom piece on.

Next remove the coin filler angled tube. Two screws.

Next remove the coin guides in the middle section by removing two screws on the right side. Angle it up and the guides plus the three switches come right out.

Clean the guides and the switches as best as you can with the cleaner. There is old gunked up grease inside the switches around the pivot points where the wire is attached. It'll take a lot of work to get the switches ungunked if they don't move quickly and smoothly. Mine didn't. Urg.

You can remove the switches and guide mechanism IF you write down all the color codes for the wires and where they went. I just laid it over to the side.

3. Remove the panel from the back bottom side that holds in a few plastic pivoting arms. It has one screw on the bottom holding it in. It's a bit of twisting to get it out but it does come out. Remove the E clips holding the arms, remove the plastic pieces and degrease it well, including the shaft and the holes in the arms. Reassemble, but leave the E clips off. Test movement. If it doesn't move smoothly you either have a burr or gunk on the arm. Mine had 3 places on various arms where they didn't fit well and I had to remove a slight bit of plastic from the bottom of the hole in the arm to make it swivel smoothly. DO NOT TAKE OFF TOO MUCH.

4. Remove the switch from in front of the motor assembly. Remove the 2 long and 1 short screw holding the motor in place. Remove the motor. Degrease the outside.

Remove the 4 screws holding the gear box together and open the gear box. MAKE A NOTE AS TO WHERE EACH GEAR GOES.

Thoroughly degrease the gears and the box. Mine had dirt in it as well... Re-lube and reassemble.

Clean every pivot point you can find on every plastic arm in the lower section. Make sure they move freely.

Reinstall the motor, reinstall the switch. Make sure the metal arm that sits under the switch is making contact with the part of the motor lever gear closest to the body of the gearbox. It will try to ride on top of that part of the gear lever. Spin the motor lever by hand and it will pop down into place.

5. THIS IS THE TOUGHEST PART. Remove the arms connected to the solenoids by removing the E clips and taking them up and off. The one on the bottom solenoid comes right out. The spring will prevent you from easily setting it on the workbench so just lay it off to the side. after you degrease it and make sure it will pivot smoothly on the shaft.

The one on the top has 2 springs connected that prevent its easy removal. Degrease it, check its movement then set it to the side.

This will expose a black toothed gear. To the right of it is a big wedge shaped toothed gear. Remove it, degrease it (and the shaft of course) then degrease the black toothed gear. Degrease under it well too. DO NOT REMOVE THE GLUE HOLDING THE NUT IN PLACE IN THE MIDDLE OF THE BLACK GEAR. Put the grey one back and make sure it pivots properly. Don't forget to reinstall the E-clip.

There is a short and long arrow on the black gear and an arrow on the wedge gear. Line up the long arrow with the arrow on the wedge gear. Hold this in place with one hand while you put the arms back on the top solenoid then the arms on the bottom solenoid. Reinstall the E-clips.

6. Turn it over and clean/degrease the arms over the top of the red price selector. Remove the screw in the middle of the price selector and take it apart. You'll have to bend a couple of the plastic arms a bit to get it out. As long as they aren't brittle you'll have no problems with this.

Degrease all the parts well.

When you remove the price disk this will expose the tiny ball bearings it pivots on. Clean/degrease them VERY well then lubricate them with the Shooter's grease.

Reassemble the pricing gear and set the price to the desired cost for a soda.

Reinstall the coin guides/switches. There's a little nub sticking out of the top of the bottom section which you must place into the guide when sliding it into place.

The brake cleaner makes the surfaces cold which attracts moisture from the air. Be sure to dry thoroughly before reassembling.

Reinstall the coin tubes.

Reinstall the coin guides for the rejected coins.

Insert the coin accept/reject mechanism.

Put it back in the machine and test!