How to Replace Cables on Cabl-Trols:
Disconnect the old cables from the trolley.
Pull one cable to bring the piston to one end of the tube.
Remove the four bolts from the headcaps, and separate the headcaps from the tube, and also separate the headcaps from the sheave brackets.
Pull the cable to bring the piston out of the tube on one end.
Cut both cables off the piston, and pull them out through the sheave brackets.
Remove the pilot washers from the sheave brackets, noting their orientation.
Remove the cable seals from the headcaps, noting their orientation.
Replace the tube o-ring seals if needed. *Note: if you ordered a replacement piston, you can skip to step 12.
Take the piston, and clamp it in a round-jaw vise with the correct bore size so that the piston is not damaged. (We use a slotted tube with the correct bore size, and we then clamp the slotted tube into the vise.)
Gradually heat up the piston with a propane torch as you unscrew each of the cut cable ends from the piston. (This breaks down the Loctite that was used to secure the cables to the piston.)
Allow piston to cool, inspect for damage, replace u-cups on piston if needed.
Determine which way the new cables are going to go, based on the orientation of the cable seal and pilot washer noted in steps 6 & 7. (The piston end should have the shorter screw, and the trolley end should have the longer screw.) Feed the cable through just like the old one was. (Cable seal passes through bracket.)
Lubricate the cable seal with Teflon grease for pneumatic service, or oil for hydraulic or low-friction service.
Replace the cable seal into the headcap by tucking in the lips, and replace the pilot washer into the sheave bracket.
Apply Loctite 242 to the piston screw, and tighten it all the way into the piston.
Lubricate the piston u-cups with Teflon grease for pneumatic service, or oil for hydraulic or low-friction service, lubricate at least a few inches of tube in front of the piston, then push the piston back into the tube by gently tucking in u-cups.
Attach the head and sheave bracket to the tube, and then repeat from step 2 for the other cable. (Applying a controlled air feed to the port will move the piston to the other end of the tube. Skip steps that are not applicable.)
Connect the ends of the cables to the trolley, and run the trolley & piston up and down the tube by hand to be sure everything is properly assembled.
Proof-load and pretension the cable according to the attached sheet. (Fish Scale method is easiest, and most reliable.
TRAC-TROL CABLE ASSEMBLY AND SEAL REPLACEMENT INSTRUCTIONS:
- Remove the unit from machinery, and place on clean work table.
- Loosen the set screws (#24) in the trolley (#25), and then disconnect the old cable subassemblies (#8) from the trolley.
- Remove the retaining rings (#21), and then remove the two guide rods (#23) and the trolley (#25).
- Remove the four headbolts (#2) at each end, and separate the heads (#3) from the ends of the tube (#14).
- Grasp the cable and pull to bring the piston (#13) out of the tube at one end.
- Cut both cables off the piston, and discard the old cables.
- Before proceeding to remove the piston screws (#35) from the piston (#13), it may be necessary to slightly heat the piston to break down the threadlocker that secures the cables to the piston. Start by wrapping the piston with cloth (exposing only the piston nose which requires heating) and place in a round jaw vice; be careful not to damage the piston.
Gradually heat up the piston (#13) with a propane torch as you unscrew each of the cut cable ends from the piston.
Allow piston (#13) to cool before removing from vice.
- Lubricate all seals with pneumatic grease (Magnalube-G® with Teflon®, or similar) for pneumatic service, or oil treatment (STP® Oil Treatment, or similar) for hydraulic or low-friction service.
- Replace the piston u-cups (#10) with new (observe the orientation of the old u-cups)
Replace all of the seals in the heads: The head o-rings (#6), the cushion seals (#7), and the needle o-rings (#5).
Clean the tube (#14).
- Determine which end of the new cable assembly (#8) should connect to the piston (#13): The piston end should have the shorter piston-screw (#35), and the trolley end should have the longer trolley-screw (#31). Take care not to scratch the nylon on the cable.
- Replace the cable seal (#34) into the head (#3) by tucking in the lips, and replace the pilot washer (#33) between the head and the rod flange (#22).
- Apply threadlocker (Loctite® 242 or similar) to the piston screw (#35), and tighten it all the way into the piston (#13).
- Lubricate a few inches inside the tube (#14) in front of the piston (#13), and then push the piston back into the tube by gently tucking in the lips of the piston u-cup (#10).
- Attach the head (#3), rod flange (#22), and sheave bracket (#17) to the tube (#14) with the four screws (#2).
- Move the piston (#13) to the opposite end of the tube (#14) by applying a controlled air supply to the port. Make sure the air flow rate is set very low to prevent high speeds.
- Repeat steps 14 - 19 for the other cable at the other end of the tube.
Replace trolley (#25), guide rods (#23), and retaining rings (#21).
Connect the trolley screws (#31) to the trolley (#25).
- Proof-load and pretension the cable according to the Proof-loading instructions.
- After the cables are properly tensioned, retighten the two set screws (#24) that are in the trolley (#25).