IME, JCB pushes that stuff on customers like no other......"your machine will sieze the hydraulics in 1 minute if you don't use it"
Ed
That was also the impression I got.
Get this though. According to a local JCB dealer, quote
"recently JCB has recommended the use of ISO 32 (colder climate) or ISO 46 (warmer climate) hydraulic oil and to stay away from mineral oil because they believe it is causing damage to gaskets and seals". WTF.? Their own brand HP 15 oil is mineral oil FFS....!!! (Still can't believe I missed the word "mineral" on the spec sheet
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In my experience all manufacturers promote their own-brand oils to a certain degree, but usually always have a listing in their manuals for non-OEM fluids. JCB are the biggest "doom & gloom merchants" I've ever come across when it comes to using non-OEM fluids.
That, and I don't know if they still do, but JCB used to be notorious for "designing" their products to use "special stuff". I recall an older loader/backhoe, don't recall the model, but you had to use their "secret recipe" hydraulic brake oil, a very low viscosity oil, like a 5W or something like that. If you used standard hydraulic oil, AW32 or higher viscosity, it would cause poor performance of the braking operation.
That's exactly what I'm on about here. The JCB recommendation is actually an ISO 15 viscosity hydraulic oil, but at the lower end of the range below SAE 10 lines get well & truly blurred. In truth the SAE engine oil viscosity classification is too "coarse" and isn't really designed to go down that far, despite the fact that damping oil for motorcycle forks is often available in all sorts of weird & wonderful viscosties from SAE 2.5 to SAE 7.5.
If you look for it there are actually plenty of options for ISO 15 mineral hydraulic oil around that matches JCB's spec, although probably not at your local NAPA or anything containing "farm" or "tractor" in the name of the store.