<img src="https://www.princessauto.com/ccstore/v1 ... ;width=300" alt="1/2 in. dr to 3/4 in. dr Impact Socket Drive Adapter"/> @Eugen Put this on a torque wrench set on near max . You will have better control of the pin spanner . If you need more than a 200lbs force you will tear the pin holes up . you may need the assist of a blue flame spanner wrench to help your pin spanner wench .Eugen wrote: ↑Wed Jul 20, 2022 2:58 pm My understanding is that on old large cylinders (like 4" diameter) some excessive forces might be needed to open them up. Just because the pins coulde span the 4" it does not always mean you can actually open up a large cylinder. Also, the pins must have a good firm grip on the holes, otherwise you'll deal with something a lot worse if the pin holes in the cylinder cap get damaged.
In any case, I wasn't going to risk that, and ordered the wrench in the picture above, but it needs the 3/4 in drive.
Bob, I considered an adapter, but I'm not sure it would be strong enough to take some big forces (i.e. long extended pipe on breaker bar).
If possible best crack loose on machine before removeal . If you need help with the blue flame spanner , just call you have my number . Most time it takes 2 guys to get them to budge . One on the torch and one on the wrench .