Bobcat T190 hydraulics

[BrokenMB]

So. Went to use skid steer to move snow after sitting for a couple weeks and shuts down on hydraulic pressure after 10 seconds. My lcd display is messed up so can’t read code. Thought maybe froze up as it had been cold. Started and couldn’t lift bucket and no tilt but I could drive it for 10 seconds before it would shutdown on alarm. 5-6 goes of this I got it in heated garage. Changed hydraulic filter and topped up all fluids. Still doing it. Thinking a pressure sensor What has me confused is that I could drive it fine. Tracks turned well but no loader functions. There is another hydraulic filter under the cab that I will change but have to drive out of garage as no room to lift cab. Any thoughts ?

 

[BrokenMB]

2005 model if it makes a difference

 

[BrokenMB]

No one has any idea ? Or are people seeing this. Maybe I posted it wrong somehow

 

[Simon C]

So. Went to use skid steer to move snow after sitting for a couple weeks and shuts down on hydraulic pressure after 10 seconds. My lcd display is messed up so can’t read code. Thought maybe froze up as it had been cold. Started and couldn’t lift bucket and no tilt but I could drive it for 10 seconds before it would shutdown on alarm. 5-6 goes of this I got it in heated garage. Changed hydraulic filter and topped up all fluids. Still doing it. Thinking a pressure sensor What has me confused is that I could drive it fine. Tracks turned well but no loader functions. There is another hydraulic filter under the cab that I will change but have to drive out of garage as no room to lift cab. Any thoughts ?

So bucket tilt back is a different solenoid is my guess than the boom up solenoid or bucket dump solenoid. I did figure one gentlemans hydraulic problem out with a complex schematic, but with no electric or hydraulic schematics most people wont say nothing.
If you find the main control valve maybe post a picture of it and see if you can figure out which spool of control valve goes to which cylinder.
Might be able to figure out that way.
Simon C

 

[HarleyHappy]

Think I would be looking at the hydraulic lock out switch.

 

[JBrady]

Without a code, you are kinda shooting in the dark. If it was me, I'd try the easy things you already mentioned first. If no luck, get the LCD screen fixed or have a tech plug into it with a laptop. Will it idle for longer than 10 seconds? Like just start the engine, but don't put the green operate button. Is it the hour screen that you are not able to see or do you have the keypad start? You can see the code from either screen.

 

[BrokenMB]

Ok. So got lcd display working. Have a 05-22 code ( charge pump ). I ordered a new solenoid to try hoping that’s all it was but no. Still the same. Was going to put a guage in but local hydraulic shop couldn’t make a fitting to screw in where solenoid goes. I’ll have to try a different way. If I leave the solenoid unplugged it will stay running with the warning light staying on. Is there anything other then replacing charge pump I should be looking into

 

[JBrady]

I would do these 3 things next:
1) read through this post: https://www.heavyequipmentforums.com/threads/bobcat-t-250-low-charge-pressure-issue.46853/
2) cut open hydraulic filter to look for metal shavings
3) connect a hyd test gauge. Several videos on youtube for testing charge pressure.

 

[willie59]

First thing to check is the drive belt and belt tensioner, that belt has to be tight. If it's not it won't make enough charge pressure and functions won't work.

 

[BrokenMB]

First thing to check is the drive belt and belt tensioner, that belt has to be tight. If it's not it won't make enough charge pressure and functions won't work.

I checked belt today. It looks good and tight. Started and watched until it shut off. Looks ok. Pump was turning

 

[Mbar]

Check charge pressure at filter with gauge and verify that you have a bad charge pressure sensor. Also pay attention if park brake / is on or off. Should be around 350 psi.

 

[BrokenMB]

So finally got a guage on machine. Idling 50 lbs of hydraulic pressure. Wide open 250 lbs pressure

 

[Simon C]

Sounds like from Mbar's figure that you are low on pressure. I have only changed the drive sprockets on these units and the case drain filters in the bottom of the pump compartment.
Maybe someone else will chime in.
Simon C

 

[Mbar]

If you only have 250 wide open with lap bar up or park brake on. That eliminates brake seal failure. Next I would look at charge relief in hydrostat. Also does machine have a hydraulic cooling fan.

 

[BrokenMB]

So. Ordered a new spring for charge pump. Spring is bigger then one I took out. So installed with no shims. 245 at idle once oil is warmed up. Wot 320 lbs. if I plug sensor in it will still shut down on low charge pressure. I also put a new belt on. It needs it anyways. What next ? Think I’m going to install shim or 2 and get wot pressure up to 360-380 lbs

 

[BrokenMB]

If you only have 250 wide open with lap bar up or park brake on. That eliminates brake seal failure. Next I would look at charge relief in hydrostat. Also does machine have a hydraulic cooling fan.

Machine does have hydraulic cooling fan but it is not running ?? Problem maybe

 

[BrokenMB]

Machine does have hydraulic cooling fan but it is not running ?? Problem maybe

Sorry hit post before ready. Installed 1 medium shim wot 370lbs. Idle 270

 

[HarleyHappy]

Yeah, the fact that the fan is not working, could probably be a diagnosis of a coupling failure.

 

[BrokenMB]

Yeah, the fact that the fan is not working, could probably be a diagnosis of a coupling failure.

So I’m going to look into this today. Does cooling fan supposed to run all the time ? Seems to me it has to as hydraulic flow goes through motor. I can’t see how it could cut on and off being hydraulic

 

[BrokenMB]

Got cooling fan running. Small chunk of rubber stuck in valve. Got it cleaned up and checked charge pressures again
Idle 290. Wot 380 lbs. plugged sensor back in and shuts down on low charge pressure. ??? The new sensor I put in I just ordered on amazon (prob Chinese ? ). Maybe it’s no good. I’m going to get a voltage test at plug to rule out a broken wire somewhere