Cleaning the welding shoe of an extrusion welder is an important step when stopping work for the day or any extended period of time. 

1. Extrude until six inches of extrudate comes out of the shoe.
2. Cut a piece of rod about 8 inches long. Insert one end of the rod into the end of the shoe. Move it in a small circle along the edge of the hole of the shoe. Wait 5 seconds.
3. Slowly pull out the rod. The extrudate inside the shoe will come out with it.
4. While wearing a heat-resistant glove, remove the welding shoe holder. 
5. Look behind the welding shoe holder into the back of the shoe. Gently remove any extrudate from the back of the hole in the shoe. Be careful not to cut into the shoe.
6. If any rod pulls out of the back of the shoe and remains on the brass nozzle, cut it off of the nozzle.
7. Brush off any extrudate from the shoe and the nozzle.

When installing a plug on to a power cord:

• Screw down the wire contacts on to the bare electrical wire only and do not clamp down on the insulation of the wire.  Bad contacts cause sparking which may cause the cord to heat up and may damage equipment. 

Ensure your tool is completely cooled down before shutting off:

• Repeatedly shutting down the tool without allowing it to cool adequately may cause the element to crack; the cracking of the ceramic element may also cause the mica tube to burn or peel. 
  
  

Watch for a plugged air intake:

• A plugged air intake will cause bad welds. Regularly check that the air intake is clear. Clean it with a soft brush when needed.

If a tool's heater tube gets wet:

• Do not turn the heat on right away the next time the tool is started as there is a risk of damage to the element and mica tube.  Run the blower or tool without heat for 10 minutes so that the moisture is safely blown off prior to slowly increasing the heat to the desired level. 

​The two hold-down assemblies and the green belt in the picture below keep the top layer of membrane flat on the bottom layer as it is heated by the nozzle, just before the drive tire presses down on it.

​If your Variant T1 stops driving while welding, check that the heater locks correctly into the welding position. 

After allowing the tool to cool down completely. Slide the heater all the way to the right/outside of the tool. Note that you can now see a groove in the guide shaft.
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In the picture below, a small flat screw driver is being held against a ball bearing set screw.

• The welding shoe must only be changed when the tool has attained its operating temperature. Wear temperature resistant gloves.
  
• Remove the welding shoe holder (17) by unfastening the clamp screws (18) from the extruder nozzle (19)
• Every time the welding shoe is changed, clean the extruder nozzle (19) of welding residue. The extruder nozzle has a left-handed thread. Make sure that the nozzle is screwed in tight by turning it counter-clockwise using a 13 mm wrench.
• Remove the welding shoe (5) from the welding shoe holder (17) by either
  1. Unfastening the fastening screws (20), or
  2. In the case of an older shoe, unfastening the four screws at the rear of the welding shoe holder

• Paper towels, and a solution such as Goo Gone to clean the tire residue off of the rim
• Utility knife
• Hot soapy water in a bucket
• For VARIMAT, UNIMAT V, HEMTEK upper wheel: 8mm hex tool
• For VARIANT T1, UNIPLAN, UNIROOF E, VARIANT, UNIFLOOR, MINIFLOOR: 2mm hex tool
• For UNIROOF AT/ST, HEMTEK lower wheel: 2.5mm hex tool
• For UNIPLAN narrow wheel: External circlip removal tool

1. Put the new tire in the hot soapy water.
2. Remove the wheel with the tire that needs to be changed:
   • VARIMAT drive wheel: Remove the green round belt and the 8mm hex bolt and washer; pull off the wheel; remove the parts inside the rim. Take the key out of the keyway in the axle so that it does not fall out and get lost while the rim is off.
   • VARIMAT rocker wheel, UNIMAT V narrow wheel, HEMTEK upper wheel: Remove the 8mm hex bolt and pull off the wheel.
   • UNIPLAN narrow wheel: Use an external circlip removal tool to remove the circlip. Then follow step 4.
   • VARIANT T1, UNIPLAN, UNIROOF E, VARIANT, UNIFLOOR; MINIFLOOR: Turn the tool on its side and drive the wheel until the set screw on the inside of the rim is visible. Loosen the set screw with the 2mm hex tool and pull off the wheel.
   • UNIMAT V Tape wide wheel: Remove the 8mm hex bolt and washer; pull off the wheel. Take the key out of the keyway in the axle so that it does not fall out and get lost while the rim is off.
   • HEMTEK lower wheel, or UNIROOF AT/ST: Loosen the two screws on the side of the wheel with the 2.5mm hex tool, and remove the plate. Pull off the tire and the ring under the tire.
3. Cut the worn tire off with a utility knife.
4. Clean any tire residue off of the rim.
5. Take the new tire out of the hot soapy water. With the rim laying on a flat surface, hold the edge of the tire over the closest edge of the rim with both hands. Move one hand to the left and the other to the right to slip the edge of the tire over the rim
6. Repeat this motion to push the tire further onto the rim until the tire is on almost all of the way.
7. Use the heel of each hand to push the tire on the rest of the way.
8. Check closely that the tire is inside the edge of the rim all the way around.
9. Reinstall the wheel.

​Many of Leister’s tools utilize a lock pin to hold the nozzle in position during welding and cooldown. The lock pin is designed to snap if excessive force is put on the heater in order to prevent more expensive damage to the tool.
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The most common reason for a lock pin to bend or break is the tool being lifted or carried incorrectly. The correct methods of carrying the tool are with both hands under the frame, or with one hand under the frame and the other holding the black carrying handle.

In this guide, parts will be referred to using the numbers indicated in the VARIMAT V drawing below. As an example, see lock pin (79).

• Contact cleaner or rubbing alcohol
• Cotton swabs
• Small flat screw driver
• Torx screw drivers, T10 and/or T20, as needed to disassemble the tool housing

​Note: Always change both brushes at once. If one brush needs to be changed, change them both.

If you are having problems with your power cord or extension cord, follow this checklist to confirm your power source and check your plugs, sockets and power cord:

If your VARIMAT is not powering down completely but you suspect a power problem, check your power source.

• If you are working from a generator:
  • Confirm that the fuel is clean (especially in the winter)
  • Check that its output is good
  • Check that the total power of all tools connected is not more than 80% of the continuous power rating (not the standby power rating) of the generator.
• If you question any of these, run only the VARIMAT with clean fuel and no extension cord and see if your problem goes away