My Thomas T133 looks like it has never had the hydraulic oil filter changed (1,700 hours). It is 3.75" in diameter and about 14" long (5 micron filter). The filter is mounted on a standard bulkhead filter mount - i.e. the hoses come into the top of a bracket / manifold assembly and the filter screws on from the bottom; the mount bolts onto the sidewall inside the engine compartment. The sidewall happens to be the inside of the 8 gallon hydraulic oil tank (actually 10W-30 SJ motor oil). At any rate ... I purchased the correct replacement filter, but can't get the original filter to unscrew. Naturally, looking down from the top it needs to turn clockwise because the filter actually screws on from the bottom - long-winded way of saying, I'm turning it in the right direction. Tried on of the rubber strap wrenches that I use for my automotive oil filters - no movement at all. Purchased one of those nylon strap wrenches that has a 2" nylon web that rolls up on a hollow piece of square tube which accepts a 1/2" breaker bar - inserted a long 24" breaker bar, still no luck. Weeks ago I put some penetrating oil on the top of the filter (Kroil brand) which I was hoping would soak into the top of the filter. Any suggestions would be greatly appreciated.