Advice on buying used Bobcat B250

   / Advice on buying used Bobcat B250
  • Thread Starter
#11  
Thanks guys for all the reassurance, I bought the B-250 last week and am looking forward to many hours on it. I sorted out the 4 wheel steering issue right away, everything works really well. The ground was still really wet, it did make ruts, but not much more than our Massey 50 with AG tires. With the 4 wheel steering it did not push up or tear any grass like our Massey would.

I believe this machine will get all the work done and more!

It going to be a great summer.

Anyone ever use this sort of machine to move snow, how well does it work for that?

Jason
 
   / Advice on buying used Bobcat B250 #12  
</font><font color="blue" class="small">( Anyone ever use this sort of machine to move snow, how well does it work for that? )</font>

The Bobcat literature claims it can go about 5 mph, which is way too slow for serious plowing. Of course, the literature is frequently outdated... so your machine may be able to move a bit faster.
 
   / Advice on buying used Bobcat B250 #13  
Jason,

You don't need to hear from me, now that you've already bought it, but it sounds to me like you got a good deal on a machine that will do what you bought it to do - and that's pretty much the whole objective.

I'm still very happy with my EF-500, but haven't put too many more hours on it in the last 6 months or so, because I've had to travel more for other kinds of work.

Once upon a time, I had the reputation of being a bit of a tire nut (not to mention hp nut, transmission nut, lights nut, gauges nut, well, just a nut), and I understand your concern about the tires. I replaced my original tires with Michelin XM-37's that were just a little bigger in diameter, but a couple inches wider. The fact that they're radials also improved traction quite a bit. So, if you find yours aren't up to the job, that might be an option. I didn't have any problem with width clearance on the EF-500, like I did with the Kubota L4310, but keep in mind that you'll have less power if you go to larger diameter tires.

As to your original question about the wheel alignment, that was answered quite nicely. You'll find that, because the steering is hydraulic, it tends to go out a bit after a lot of heavy use. Resetting is pretty easy, as you saw in Bobcatboy's excellent response. My EF-500 does the same thing, but it's got an electric crab-steer option, so all I have to do to reset the alignment, is flip a switch to crab-steer mode, cycle the steering back and forth once and flip the switch back.
 
   / Advice on buying used Bobcat B250 #14  
I have recently purchased a used Bobcat Backhoe B250(2005) When I push the "Push to Drive" button, the fuse blows. When I tried a bigger fuse, I smell something like burning plastic on wire. Any thoughts?
 
   / Advice on buying used Bobcat B250 #15  
Do you have a manual ? I have the B200, it is not the same but similar. There is a solenoid activated valve which is energized by the green button. I'm guessing the circuit is 12V powered. You must have a short in the wiring. Possibly rubbed the insulation off a wire ? Worst case scenario, the solenoid is toast. I have attached a schematic of the hydrostatic drive (hydraulic) circuit.

Look for item 26 which is actually 2 identical pressure switches (to detect if the foot pedal is in the neutral position). Right below is the solenoid valve which in the de-energised position simply bypasses the servo which controls the position of the main hydrostatic pump swashplate. By bypassing any hydraulic pressure to the swash plate servo, it will "idle" (find the position of least resistance) and thereby the unit will not move. Energise the solenoid valve and now the proportional pressure from the hydro pedal (either forward or back) is communicated to the servo controlling the swash plate, which in turn modulates the output of the main hydro pump in the appropriate direction.

Because the valve is shown outside of the dashed rectangle for the main pump group, I take it that the valve is remotely mounted. All the stuff within the rectangle is hard mounted onto the pump body itself. Track down where the valve is and see if it has a removeable solenoid. If it is removeable, take it off, disconnect the connector and measure the resistance of the coil at the connector pins. It should be about 10ohm, more is ok. Much less does not sound good. But if the solenoid is removeable you should be able to get a replacement for a reasonable price. Just might have to wait 3 weeks like I just did for a complete set of filters for my B200....

Good luck
Keith
 

Attachments

  • Bobcat B200 Hydrostatic schematic.pdf
    91.4 KB · Views: 801
   / Advice on buying used Bobcat B250 #16  
No feedback yet, but in trying to troubleshoot my own loss of hydro function, I this weekend removed the floor in the cab to see what I have there. I changed out the hydraulic oil filter, but it made no change to my symptoms.

So here are some pictures
Here is where you can see a bracket with the 2 pressure switches and the electrical solenoid valve. This is looking from the RHS of the tractor towards the LHS. The solenoid valve is the 3rd item on the right hand side, partially hidden by the hoses. Unlike the pressure switches, the solenoid is at the bottom, where it looks like a bit of a PIA to access.
View_from_RHS.JPG


Next, here is looking from left to right to where the hydro pedal assembly is mounted: The edges of the manifold assembly are pretty sharp and have been cutting onto one of the hoses, so I will have to tie it out of the way to avoid it getting worse.
View_from_LHS.JPG



Here is a close up view on the connectors on the presure switches: as you can see, they have a philips screw that holds it on. I suspect that the solenoid for the valve is similar. There are also some relays involved, which are in the fusebox, but I think they are quite well protected there, whereas the wiring underneath is exposed.
View_on_connectors.JPG


Hope this helps with your troubleshooting.
 
   / Advice on buying used Bobcat B250 #17  
I have to say the workmanship in this area which is normally hidden is disapointing. Far too much rubber hose has been used, where rigid hose would be much more compact and last basically forever. When the rubber hose reaches the end of its life it will be expensive.

I have a small leak at the back where the tube bundle exits to the backhoe, but so far I have not used the backhoe much. I have a much larger leak in the front and I have not traced it yet, but believe it can only be the steering cylinder or the oil cooler mounted in front of the radiator.

I spent much of the morning figuring out where all the grease zerks were and have found the grease passage blocked on one of the pins on the loader. I replaced the 10mm metric grease nipple, but that was not the problem. I may have to pull the pin to clear out the passage. I switched to a non lithium "marine" grease for better water repelling properties.

Also replaced the engine oil filter today and fixed a badly leaking dipstick tube. The dipstick tube is meant to be a tight fit in the bore in the crankcase, but mine isn't. The tube also has a recess for an O-ring to seal between the tube and block, but my dipstick tube is too high to allow the o-ring to engage in the bore in the block fully. The engine side bracket is probably off. I used permatex sealant on the joint and will see how it works out. If not, I will have to bend the engine side bracket lower and get the right size O ring next time around.

Bought 2 1000psi guages and 2 10 000 psi guages to use for troubleshooting the hydrostatic system. I figured I may as well permanently mount them (instead of having them buried in a drawer in the garage) so I will be making an accessory instrument panel. At the same time, I will also fit a guage to indicate pressure at the outlet of the gear pump for the implements. That should allow diagnostics of the majority of the hydraulic system from the drivers seat in future. Basically will be able to see the front and back servo pressure on the swash plate (which is supplied by the charge pump) as well as the forward and reverse pressures in the high pressure hydro circuit.

There is already an annunciator light in the panel for a blocked (bypasing)hydraulic oil filter, so the only thing not covered is the temperature and level in the hydraulic oil tank. That will be taken care of by a combined level/temperature switch pair that will be mounted through the top of the tank. I will have to add 2 LED's to signal overtemp and low hydraulic fluid level. Perhaps a buzzer in that circuit too for a warning.

The guages should arrive this week, so I have to plan out the 1/4" hoses between the tap points and the new panel. 1/4" female NPT on one end and an unknown metric male on the other end.
 
   / Advice on buying used Bobcat B250 #18  
I have an Earthforce EF3. Its basically a B200 with Four Wheel Steer and a different loader up front. Hydraulics are the same a far as I can tell. My green button failed intermittently. I traced it to a bad solenoid, the solenoid/relay to the far right in the top picture posted by Westcliffe01 above. I took to my bobcat dealer, who is real understanding. He thought it was the green switch, though I thought I had already ruled that out. Well he figured out it was the green switch and bypassed it with another momentary switch. Works like a champ.
 
   / Advice on buying used Bobcat B250 #20  
i have the same problem with the steering alignment. the bobcat drives sideways.
 
 
Top