LS190 Stalls engine when engaging AUX hydraulics

[skidsteer.ca]

I sold a plow and blower to a fellow with a 190. He lives several hours away in the northern Mb. The problem he is having is if he moves the auxilary hydralic control handle more then just a bit the demand on the pump kills the engine dead.
The plow will work but angles slowly and the blower won't work at all. It just barely turns.
Both attachments are new, the bower I used for a few hours personally before I sold it and it worked fine.
It seems the flow is severly restricted to the front couplers so instead of 21 gpm there is mayby only 2 or 4 gpm there.
I"m also concerned that perhaps the relief pressure is way too high as the engine imo should not stall even if no hoses are conected to the couplers on the loader and one operated the aux handle. The machine should come up to relief pressure in this situation and labour the engine but it should not stall.
This being said he has no complaints about the boom lift and tilt or the cycle time of those functions.
I'm thinking it either has a plugged hydraulic coupler on the loader or a kinked tube line or a pinched hose in the circuit from the auxilary spool to the coupler that is severly limiting flow.
Anyone with experience on a LS190 want to comment on weather the aux hyd will stall their loaders engine if activated with no attachment conected, or what the system relief pressure is for this machine.
The fellow is not a mechainc and does not likely want to know how his machine works only that it does. However being he is in a remote location I'm trying to walk him through this long distance to see if its something minor.
I willbe downloading a copy of the manual as soon as I find out if it is a straight LS190 or a LS190B
Both are available online reasonably priced
Your comments are welcome.
Ken

 

[jerry]

If he purposely tries to lift something too heavy will it stall the engine or open the relief? Just recently there was a poster on here that had a piece of plastic lodged in the coupler but as you say the engine should not die even when dead headed if it is at operating rpm.

 

[Mike10]

Is it a LS190 or LS190.B? The .B's have a switch on the control valve that will shut the engine down if the aux hyd are engaged and you leave the seat. However, there are two fuses that if they blow will cause the engine to die when the aux hydraulics are engaged. I'd have to look which fuses are involved but just check them all, both in the cab and the enginge fuse panels.

 

[Earthwerks Unlimited]

Is it a LS190 or LS190.B? The .B's have a switch on the control valve that will shut the engine down if the aux hyd are engaged and you leave the seat. However, there are two fuses that if they blow will cause the engine to die when the aux hydraulics are engaged. I'd have to look which fuses are involved but just check them all, both in the cab and the enginge fuse panels.

My LS185.b does this when the diode in the rear fuse box goes.

 

[skidsteer.ca]

My LS185.b does this when the diode in the rear fuse box goes.

I can ask him to check the fuses unfortunately his shuts down anytime the aux hyd are engaged, so hard to test the switch theory.
The tag in the cab says it's an L190 ser. # *N6M436608*. he thinks it is a 2006
Also waht is the difference between a L190 and a LS 190 we can only find manual for the LS
Ken

 

[Mike10]

I can ask him to check the fuses unfortunately his shuts down anytime the aux hyd are engaged, so hard to test the switch theory.
The tag in the cab says it's an L190 ser. # *N6M436608*. he thinks it is a 2006
Also waht is the difference between a L190 and a LS 190 we can only find manual for the LS
Ken

There is a 15A fuse in the cab fuse panel and a 25A fuse in the engine compartment fuse panel. Just turn the key on and see if power is going through the fuses. Either one will cause the problem.
The LS190 used a complete different drive system from engine to hydrostat components. The fuse location is more or less the same between the two until about 2008 when the cabs were changed.

 

[skidsteer.ca]

There is a 15A fuse in the cab fuse panel and a 25A fuse in the engine compartment fuse panel. Just turn the key on and see if power is going through the fuses. Either one will cause the problem.
The LS190 used a complete different drive system from engine to hydrostat components. The fuse location is more or less the same between the two until about 2008 when the cabs were changed.

Well that sounds like the kind of tip I want to hear. Fingers crossed.
Want to give me some theory on why it works that way?
Thanks
Ken

 

[Mike10]

Well that sounds like the kind of tip I want to hear. Fingers crossed.
Want to give me some theory on why it works that way?
Thanks
Ken

On the large frame loaders there is a switch on the control valve aux spool. This switch keeps hyd driven implements from starting inadvertantly when the engine is started in the case the aux hyd control lever was not returned to neutral when the engine was last stopped.
If the lever is not in neutral the engine will crank but not start. There are two sources of power to the fuel shut off solenoid. One goes through the control valve switch. If the aux is in neutal the engine will start. If you get out of the seat with the aux engaged the engine will stop because no power is going to the fuel shut off solenoid. There is a switch on the instrument panel for aux over ride. Pressing this switch allows you to exit the seat, in the case of a backhoe, without shutting the engine down. This is the second source of power to the fuel solenoid.
The source of this second circuit originates at the engine fuse panel 25A fuse. This fuse sends power to the run relay. If the diode is good, the one mentioned by earthworks, the relay is energized and power is sent to the 15A fuse in the cab fuse panel. From there the power goes to the instrument panel and the panel sends power to the fuel solenoid when the aux lever is moved from neutral.

 

[skidsteer.ca]

On the large frame loaders there is a switch on the control valve aux spool. This switch keeps hyd driven implements from starting inadvertantly when the engine is started in the case the aux hyd control lever was not returned to neutral when the engine was last stopped.
If the lever is not in neutral the engine will crank but not start. There are two sources of power to the fuel shut off solenoid. One goes through the control valve switch. If the aux is in neutal the engine will start. If you get out of the seat with the aux engaged the engine will stop because no power is going to the fuel shut off solenoid. There is a switch on the instrument panel for aux over ride. Pressing this switch allows you to exit the seat, in the case of a backhoe, without shutting the engine down. This is the second source of power to the fuel solenoid.
The source of this second circuit originates at the engine fuse panel 25A fuse. This fuse sends power to the run relay. If the diode is good, the one mentioned by earthworks, the relay is energized and power is sent to the 15A fuse in the cab fuse panel. From there the power goes to the instrument panel and the panel sends power to the fuel solenoid when the aux lever is moved from neutral.

He can angle the snow blade slowly and the engine will run but not if he tries to put too much oil to it, Must be just the point where the spool switch activates off the aux valve??
Makes sense though, most of the other brands drop the aux flow when you shutdown the engine.
Ken

 

[Mike10]

He can angle the snow blade slowly and the engine will run but not if he tries to put too much oil to it, Must be just the point where the spool switch activates off the aux valve??
Makes sense though, most of the other brands drop the aux flow when you shutdown the engine.
Ken

The 15A fuse in the cab fuse box also supplies power to the windshield wiper if equipped. I have seen the wiring to the wiper motor short out which blows the fuse, but it can also blow the diode in the engine compartment fuse panel since it is only a 1A diode.

 

[Earthwerks Unlimited]

The 15A fuse in the cab fuse box also supplies power to the windshield wiper if equipped. I have seen the wiring to the wiper motor short out which blows the fuse, but it can also blow the diode in the engine compartment fuse panel since it is only a 1A diode.

My bet is the diode. Easy to check with a VOM. It's encased in a black rubber "connector" of sorts similar to what you'd find on a two wire electrical connector. Dealer gets $15, but I made my own with a 50 cent part from Radio Shack. Don't have the part number at hand but if you search the archives here I have a thread here about it.