3 Tools Required
1. Drift pin driver
2. Philips screwdriver (small)
3. Standard Screwdriver (small)
There are four ways they can fail:
1. Compression, Braking, Bar worn, Glue obstruction.
First on the dynamic end remove the drift pin, this will allow you to remove the compression assembly. After removing the compression assembly remove the five face plate screws, remove the face plate. Inside you will see 2 springs, and 2 dogs, one is the compression dog the thicker one, the other is the brake.
Trouble shooting—If the compression assembly is not moving 3/16~1/4 then remove the compression dog and rotate it 180 degrees axially not end for end (the penitration is not centered) Reassemble in reverse order.
— If the brake is not holding (what is gained from each compression is lost when the handle is released) remove the brake dog and rotate it 180 axially.
When reassembling push the release button while driving the bar through the compression assembly. You do not have to replace the drift pin unless you want to.
The bar can be reversed, but the end pin will have to be driven to stick out the opposite side. It fits into a slot on the fixed end.
These fixes will give another life to these clamps. PS Once in a while you will find that one of the dogs did not go through the hardening process correctly so the metal will be weak and wear out quickly. This can also be fixed with a round file and a torch reface the sharp grabing edge with the round file then heat treat the dog using a propane torch then quench the dog to harden the steel. CLAMP ON Woodworkers
-- another tip from cooperedpatterns