Hi All, I have a 92 Yanmar B3-1 grey market. Power is not bad but speed is relatively slow compared to newer machines (not surprisingly). I don't think there's anything wrong, I've watched videos of other B3s and they operate at similar speed. I've done fluid and filter. I'm wondering about the possibility of swapping the pump for a higher flow pump. I know it could be expensive and probably not worth it for this machine but I want to at least look into it. The pump is a Kayaba KRP4-12-12-12 CDY (shown below). It's a triple gear pump. I can't find much info about it. I don't have a manual for this machine (not yet anyway). Any suggestions on sources for a manual? I know its grey market but a U.S. manual would be better than nothing. I'd like to hear all thoughts about the feasibility of upgrading the pump. Obviously the spline and mounting flange would need to match, how common are the sizes? Hose fittings would have to match. Would a higher flow pump put too much strain on the engine? Could the lines and valves handle the higher flow? Will I lose power in favor of flow? I know a lot of these questions require specs to answer but I appreciate any advice, thank you! Jeff
Anybody swapped a hydraulic pump with a different one? Any info would be great.
I had alot of issues with my pump and I thought about going the same route. I ended up contacting Fluid Power Services in Ny. They were who does all the pump work for member " finalDrive" here on the forum. The prices to get the work done were reasonable. No one in our area does their own work. Mine is IHI. It may be work a try.
Well 1 hp of diesel power is equal to 1 gal/min at 1500 psi...so you can figure if you have extra engine power....usually you don't. ...only way to drastically improve performance is to goto load sense piston pumps. They monitor engine rpm and back off when to much power is required..a bigger gear pump will not make your machine weaker hydraulically. ...but will stall out when the diesel runs out of torque.
BTW that is a SAE b b pump....2 bolt....very standard easy to buy....any hydraulic store can order one....cubes are measured by gear sections...
In my experience the Japanese engineers are pretty good at getting everything they can from the available engine power. If you went to a bigger pump you would most likely be killing the engine frequently or at least having to feather controls a lot more, or lower the system relief settings. You can't get more of something without giving up something. The ones I worked on with gear pumps were usually set up so you could deadhead two functions, either just barely or not quite, without stalling the engine, and that was essentially at sea level which matters if your engine is not turboed.