• List problems that can occur with the traction circuit
• List causes for traction problems
• Describe basic tests for the traction circuit

Failure to maintain adequate chain/gripper block traction against the tubing can cause:

• Unusual noises at the injector head
• Tubing slippage into the well
• Ejection of tubing from the well (underbalanced)

Tubing slippage can be caused by non-hydraulic faults such as:

• Worn or damaged gripper blocks
• Wrong sized gripper blocks
• Broken or brittle elastomer pads

Excessive traction pressure can cause:

• Gripper blocks to place marks on the tubing
• Tubing to deform to an oval shape

Excessive traction pressure can be caused by:

• Thermal expansion of fluid inside hoses - simply bleed off the excessive pressure
• Problems with internal seals on the hose reel allowing higher pressure circuits/channels to leak across to the traction circuits. You’ll need a reel repair.
• The main traction pressure adjustment valve, which is a pressure reducing valve, stuck open.

A lack of traction pressure may be caused by:

• Hydraulic supply (priority pump circuit) not active
• Traction pressure bleed valve left open
• A large internal or external leak
• Incorrect traction pressure setting
• Traction pressure adjustment valve (Sun) stuck closed