I am in a position where I for sure have to replace my main hydraulic pump since it cannot make relief pressure anymore and the machine has lost a considerable amount of power in the loader and hoe.
The HST works (except for the safety valves which are on the blink due to electrical issues) but I figure I may as well replace the HST at the same time, replace any hoses which I have not already replaced, since they always fail at the most inopportune time...
The 5000psi working pressure hose and DKOL fittings can be had from
K Series No Skive Hydraulic Hose Crimp Fittings | Hydraulic Hose Hydraulic Hose Fittings (just scroll down till you see the listing of DKOL fittings) "The Hose guys" will send you a sheet with dimensions for doing the crimping so you can take the hose and fittings to your local hydraulic guy to make up replacements for you. I have already replaced every hose on the hoe and not had a bit of trouble with any of the replacement lines. I think the labor charge for cutting and fitting the hose ends for me was $60 for the hoe, after I bought the hose and fittings. I made the hydraulic shop a drawing indicating the length and which kind of fitting was needed on each hose end and it worked out great.
I am looking to use a Rexroth A10VG HST pump
Bosch Rexroth Mobile Hydraulics
I can't tell if the surplus one I found for $900 will give me the exact same functionality as before (one may be able to stall out the motor using the HST for instance, without a load valve) but given that the main purpose of the machine is digging while stationary or lifting items and then going somewhere with them, I don't believe that I will sufferer a substantial loss. Perhaps more finesse will be needed when moving dirt with the loader ? Saving close to $7000 on the rebuild (not counting labor) will be worth it to me, given that I am not charging for my seat time...
The biggest question on my mind is the specification of the gear pump. 3000psi gear pumps which will fit are <$250, but the page in the specifications section of my B200 manual is conveniently blank for the HST and gear pump so I don't know if I actually need a 4000psi working pressure gear pump or not (the relief on the hoe cylinders is set to 4000psi). I personally assume that the extremely short life that folks are seeing with the pumps on this equipment are due to gear pumps being used that are likely only designed for 3000psi in the first place combined with ineffective oil coolers on the B200. So my plan is to add a large auxiliary oil cooler to my machine at the same time and lower the oil temperature. I have not found any 4000 or 5000psi working pressure gear pumps yet, and the pump sold by loader parts source looks just like the $250 pumps being sold at Surpluscenter except that they want $900 for it and Bobcat wants $1300 for it. I figure that if I get another 1300 hours out of a $250 gear pump, I can just keep replacing them till the cows come home and be way ahead of giving Bobcat a dime.
