How to: Seal a thread with sealing cord. Featuring: LOCTITE 55, LOCTITE SF 7063

Threadsealing with LOCTITE® Sealing Cord

Threaded connections are widely used to connect pipework in pressure systems, thus sealing is essential. The most widely used liquid thread sealant in the automotive repair are anaerobic products. We will show here a repair with a sealing cord.

Get the Materials

The pipe sealing cord used in our instruction is a non-curing coated multifilamen cord that seals out air and other common gases and fluids. It can be used for leaking pipes or other pressure systems inside the workshop (not in a vehicle!).  It needs no cure time and results in an immediate, full pressure seal. 




Clean threads with LOCTITE® SF 7063 and, if necessary, roughen smooth threads.



Wind LOCTITE® 55 sealing cord onto the pipe thread in the same direction as the thread, starting from the end of the pipe. Avoid covering the first thread turn, this allows easier fitting of the pipes. See label for recommended number of wraps; apply in cross-cross pattern. Cut off cord.



Assemble the pipes as per accepted trade practice. An adjustment of 45° is possible after tightening. Parts can be re-used without any rework. Open the joint, remove old sealant using e.g., apply fresh sealant and retighten properly.


All repair and maintenance tasks shown should be done by professionals only. Please do not try this at home or if not qualified by professional education. Always follow car manufacturer's instructions.