Gee, I finally get to disagree with Swoop... ;-) but I do have to agree with his assessment of 'repair vs replace' liability issues
Actually, from where I stand, the PM tech is far less the "responsible party" than the people doing and insuring proper operator training (and thus the operator), as an explanation of what is a a "full and complete" stroke, as part of the required daily inspection that is required as part of OSHA mandated safety training and daily pre-operational check out, just like showing the operator where the brake master cylinder reservoir and the controls are, we have to inform the operators of what to look for as 'not acceptable' ["tweaking" mast when tilting to the end of the stroke, or a side shifter that shifts more to one side and a brake master cylinder loosing fluid among others].
All that said, now back to the mechanical reasons for this. I have to firmly disagree with Swoop, here. The maladjustment of the tilt cylinders does not put more force on the rear of the cylinders, which is where this break we are talking about here, is happening. What it does is extend 1 cylinder further out, making the 1 rod longer, that force is pulling away from the operator. The force at the rear of the cylinder is a force coming towards the operator.
I think you will far more likely find the 'causing stress' {A.K.A. 'root cause'} to be a force pushing against the base of the cylinder, and may be caused by the wrong sleeve/stop and shims on the outside of the cylinder rod, or by the rod bottoming out inside the cylinder, or bulldozing or maybe even a far over expected pressure setting on the relief valve. (can the truck lift the rear wheels when lifting an over capacity load? is so, you may have found the cause),
As far as "the drivers running into something with the forks raised some what and that causes a high pressure spike inside the tube", this is not an operators error, but the relief valve being set too high, even if you overload the truck, if the relief valve is properly set, it would provide relief instantly for an over pressure "spike". A properly set relief valve will not permit lifting more than a 'rated capacity' load.
I also think, when you see this sort of abuse {and this is sure not normal wear}, it is important for everyone's safety, to insure the operators understand that the design of the forklift, (referring to the "Stability pyramid" and how you get out of the stable zone at height much quicker and with far more disastrous results at height than down low, which is required to be understood [as clearly required to be included in the OSHA mandated training]) expects the truck to do virtually all of the tilting when the load is close to the floor, not when it is raised above travel heights. maybe it is time to sell that customer on a more expert trainer's services than their 'in house' trainer (or maybe invite their 'in-house' trainer to "audit" a class of your trainer to help each of them better their training skills, rather than point a finger and admit the 'in-house' trainer is lacking skills), and explain that proper training can greatly lessen the cost of these sorts of repairs.
You may find that a number of these cylinders were previously rebuilt and reused the same nut on the inside that holds the piston to the rod (and that nut backed off and is now hitting the base end of the cylinder jug), or were not shimmed to keep the expected clearances, customer wanted more back tilt so someone ground down a % of an inch off the back tilt spacer, or over time that spacer/sleeve has 'somehow' gotten shorter.
Does anyone in your area use a protractor and a level to check the actual degrees of tilt on a truck?