wheel cylinders for blitz

[Keith Webb]

Probably the best way to go is to take them to a competent brake place which will press them out and resleeve the cylinders in stainless steel. This is a good long-term solution which I (and many others) have done to blitzes.
On 3 ton cab 13 models all wheel cylinders are the same whilst if yours is a F15A the fronts are smaller.
You should also consider doing the master cylinder while you're at it. It's in an awkward place and you'll curse getting it out particularly if you have a brake booster.
It's also a good time to have a careful look at the other parts of the system like the lines (which can rust) and hoses.