Dave the Ozzie
Member
- Joined
- May 23, 2024
- Messages
- 10
Hi all, ten months ago I purchased a Bobcat 763 F HF machine with 3000 hours on that hasn't seen a lot of love of late. I only have it to do my own landscaping on our 2.5 acre house block that we only recently bought and after the usual hose here, hose there failure, tensioners seizing, all three ram seals blowing out literally, fault codes, rubbed through wiring loom etc, ect, it's actually been a pretty good machine once I got it sorted as I'm familiar with skid steers in general as I ran a one man business using Mustangs and a tipper from 1985 to 2005.
The Bobcat engineer that designed the HF system by mounting the pump directly hanging off the end of the crankshaft needs tar and feathering for his effort as apparently they pretty much all eventually fail from vibration and everyone I've spoken to uncouples the pump and ties it out of the way. One fellow even told me if left unchecked the vibration can destroy the engine crankshaft, oh joy. I've just bought a chain trencher and having an extra 38 litres of oil flow would certainly help for its efficiency. So, I set about removing the engine/pumps and putting it on saw horses while I went about designing and making brackets that attach to the engine mounts to support the HF pump, then used a flexible coupling to drive it off end of the engine. I'm extremely happy with the end result, absolutely no vibration, while I was in there I ended up replacing nearly every hydraulic hose including hydrostatic (expensive ) as preventative maintenance to save future breakdowns. For anyone that is interested in my pump mount I can post pics
Anyways, I have a question for those in the "know": the 763 is rated at 3,000-3,050 psi hydraulic pressure and mine was on 2,800. I tweaked the relief valve a couple of turns and had it at 3,600 but wound it back to a freckle under 3,400 psi. These machines with the single tilt ram don't have the greatest crowd breakout and no where as good as my old Mustang 2050 that I had twenty years ago as I'm use to running oversize buckets and am usually operating only on the front wheels. Ok, the question is what's a safe maximum working pressure to set the relief valve at considering later models are up around 3,500 psi, obviously with newer style pumps and spool valves. Sorry for the story but consider it my introduction. Lol. All the best from down under, cheers Dave.
The Bobcat engineer that designed the HF system by mounting the pump directly hanging off the end of the crankshaft needs tar and feathering for his effort as apparently they pretty much all eventually fail from vibration and everyone I've spoken to uncouples the pump and ties it out of the way. One fellow even told me if left unchecked the vibration can destroy the engine crankshaft, oh joy. I've just bought a chain trencher and having an extra 38 litres of oil flow would certainly help for its efficiency. So, I set about removing the engine/pumps and putting it on saw horses while I went about designing and making brackets that attach to the engine mounts to support the HF pump, then used a flexible coupling to drive it off end of the engine. I'm extremely happy with the end result, absolutely no vibration, while I was in there I ended up replacing nearly every hydraulic hose including hydrostatic (expensive ) as preventative maintenance to save future breakdowns. For anyone that is interested in my pump mount I can post pics
Anyways, I have a question for those in the "know": the 763 is rated at 3,000-3,050 psi hydraulic pressure and mine was on 2,800. I tweaked the relief valve a couple of turns and had it at 3,600 but wound it back to a freckle under 3,400 psi. These machines with the single tilt ram don't have the greatest crowd breakout and no where as good as my old Mustang 2050 that I had twenty years ago as I'm use to running oversize buckets and am usually operating only on the front wheels. Ok, the question is what's a safe maximum working pressure to set the relief valve at considering later models are up around 3,500 psi, obviously with newer style pumps and spool valves. Sorry for the story but consider it my introduction. Lol. All the best from down under, cheers Dave.