10 top tips to help remove seized nuts and bolts, they are the dread of everyone when it comes to repairing trucks, a two minute job of ‘just’ removing a bolt can turn into a nightmare with stripped threads, rounded heads or corrosion and rust build up between the threads in a sense welding the joint tight.
One of the few times our science lessons taught us something useful. Metal expands when hot and shrinks when cold.
So changing a bolt engine when the engine has just been running is going to take just a little patience whilst the metal cools down. We can use this principle to our advantage by applying heat directly to the bolt/nut or the area around it heating up the hole. This will cause expansion forcing the metal to break it bonds, so once cooled with a sharp tap it should be free to remove.
There is a product from Tough Technology Products in Cheshire called Freeze-Off that comes in an aerosol which when sprayed shrinks the metal whilst seeping down lubricating the threads and dissolving the rust.
Apply a punch to the centre of the bolt and whack away, hitting the bolt on the top and bottom. By applying a sharp impact the bolt will vibrate/resonate in its hole hopefully loosening it from the rust.
Using a ratchet and socket gradually work the bolt back and forth, once some of the thread become visible spray with some lubricant on them then continue tightening and untightening working the lubricant down into the rust.
So you’ve been working hard and all that has been achieved is the bolt head is now rounded, dam! Time for another tactic, grab a pipe wrench to clench the bolt head in or nut and lever away. This is fine where there is room to manoeuvre but not for a tight spot.
Ok now we are talking war and that bolt or nut is obviously not reusable it’s just about getting it free. Deeply score into the bolts head with two cuts about a third of the way down then with a hammer and chisel hit it a few times to vibrate it lose then grab some pliers and twist out. With a bolt follow the same procedure of scoring and chiselling then apply pliers for that final squeeze to break the bolt free.
Drill It Out
Broken the head off the bolt? Nut just not budging? Then it’s time to get the drill. Use a smaller drill bit and hollow down the length of the bolt. This will heat up the bolt causing it to expand against the corrosion and the hole in the centre will allow it shrink away once cooled. Now chisel the bolt out hopefully as one or in pieces.
Stripped the thread, rounded or lost the bolt head, still ruddy there!! Weld a larger bolt into a nut and weld this on to the remains of the seized bolt. The heat from the welder will cause the bolt to expand and contract helping to loosen the hole and you now have a bolt head again to apply a socket to.
When removing panels or items fixed with more then one bolt loosen all the other fittings to allow movement around the seized part. Some parts have a sequence that the bolts need to be released in, check a manual or online to confirm.
The big guns need to come out, use an air hammer to free seized nuts or bolts.
There are a number of different varieties on the market priced from £4 to £30 and if you’re a regular truck fixer it’s well worth investing in a set.
Remember screws and bolts only take two seconds to grease prior to use and could save hours of frustration. Use a copper grease before fitting, this will prove invaluable in the future if removal is required again.