series a toolcat suddenly stops

[oldphart]

i am looking at an A series 5600. talked to the dealer today and the salesman told me the toolcat has developed an intermittent problem where it will suddenly stop or sometimes just wont move after you stop. then it will work perfectly for a long time and after days or hours do it again. does anyone have any idea how to fix this? i should clarify that when it stops it isn't the engine stopping it is like the safety armrest isn't down but it is.

 

[Jabonee]

When it stops does the lift and tilt stop too? That would indicate the "TICs"(arm rest) is failing. If lift and tilt still work it could be the engine speed sensor. Could even be dirt in the brake valve. Has the unit had the service codes checked?:confused3:

 

[oldphart]

thank you. i don't know the answer to your questions yet but i will find out. the unit isn't at a bobcat dealer so the service people really don't know or have the diagnostic equipment. i have been using the search function on this forum and have some ideas now what to look for. the engine speed sensor wasn't one i had found though. so what i need to do is run it until the problem comes back and first see if the lift and curl work,if they don't work i should suspect the arm rest and if they do work then i should suspect an engine speed sensor or maybe front or rear axle speed sensors. correct??? am i chasing the right direction here? thanks again. does the a series have a function to check the codes or does it take a scanner???

 

[Jabonee]

Do yourself a big favor if you are considering buying that unit. Have that dealer have the local Bobcat dealer plug into that unit and print out a copy of the service codes. This will give you a little history like if the unit has been overheated or run low on oil. It will also tell you if the engine speed sensor is at fault or the brake solenoid. FYI those early unit have a history of drive motor failure. Service codes would show that by low charge pressure codes. The Toolcat does have an onboard diagnostic but codes can only be retrieve at the time of failure.

 

[oldphart]

Thanks that is a great idea. i didn't know the A series had drive motor failures,i thought it was the B and C series. i will ask the service dept if they can get a scan from Bobcat.

 

[mmancuso13]

Look to see if it is the famous (or infamous) 50-56 error code. That is what is sounds like to me...
This would indicate an intermittent communication failure between the dash mounted control unit and the drive controller. It then becomes a game of hide and seek finding the intermittent connector pin, or wire open... Let us know what you find out

 

[oldphart]

great info thanks. can i get the error codes without taking it to a dealer?

 

[mmancuso13]

Yes, press and hold the lights button and the latched codes will be displayed on the control panel screen. Let me know what code your machine shows

 

[oldphart]

Thanks. the toolcat isn't mine yet it still belongs to the off brand dealer and they have put it into their shop to try to fix it. their mechanic was a bobcat employee mechanic for many years so he is supposed to be pretty salty. the dealer doesn't have any of the bobcat diagnostic equipment though so there is a limit. i have asked the dealer if they will let me know what codes the machine has during the intermittent problem. if i can get a grip on the possibility i will purchase and take it to bobcat or fix it myself.

 

[oldphart]

i talked to the dealer and they told me it wasn't throwing any codes.

 

[mmancuso13]

Yikes! I am not even sure what to think. Toolcats are basically all hydraulic and there are many things that could prevent the machine from moving but none that I can think do that do so without error codes!

Maybe other TC owners can weigh in?

Bump...

 

[Jabonee]

Did the tech get the unit to malfunction when he checked for codes?? Did the lift and tilt still work?? Remember all codes are not storable and the onboard diagnostic will only show them at the time of the malfunction !! I strongly suggest that you have a BOBCAT dealer plug into this unit and see whats really going on!!

 

[SSdoxie]

Yikes! I am not even sure what to think. Toolcats are basically all hydraulic and there are many things that could prevent the machine from moving but none that I can think do that do so without error codes!

Maybe other TC owners can weigh in?

Bump...

The controller will only set a fault code when it senses a command being sent and return/response volt signal is incorrect. So looking on the bright side, no code means no random intermittent electrical problem to chase down.

In this case, as Jambone stated in his first reply post #2 is to verify if the boom and bucket stop working also or if these do still work.
If loader functions also stop then problem is in the lift arm switch or arm mounting. Loose, worn, or broken part in switch mount or arm pivot can cause the switch to move out of correct contact position and controller would interpret it as arm bar being raised while moving.

If problem is with drive only there are a number of issues that could cause it. Keeping in mind that the system is set default to "Axle Matching". A speed sensor in each differential monitors motor RPM and controller will de-stroke the pump for the faster motor to match the slower one, so if one motor stops pulling both axles stop. One of the reasons is internal failure of one or both drive motors. Also if 1 or both of the speed sensors have a build up of metal filings from the differential it could send a false signal the axle has stalled so the pump(s) de-stroke.
There is a way to turn Axle Matching Off using the control panel but I don't remember the button sequence and have no manual. Before the software update to turn Axle Matching off with the controller was added we unplugged one or both speed sensors. Machine will drive without speed sensor connect but will set a code. Disconnect speed sensors 1 at a time and test drive, whichever sensor is un-plugged and machine does not stall that is axle, motor, sensor that is creating the problem.

 

[Jabonee]

I think that axel matching is gone by that model and newer.

 

[SSdoxie]

I think that axel matching is gone by that model and newer.

Model in question is A model, first model built. All A thru C series have axle matching using 2 speed sensors, 1 in each axle. This was necessary because the hydrostatic pumps each had internal charge pump that was used for pilot pressure to stroke that pump. If charge pressure was not the same in each pump the swashplate angle would be different in each pump resulting in unequal flow to the motors so the sensors were used to monitor the speed and adjust pump stroke. Starting with D series the hydrostatic pumps change to using a common charge pump as part of the gear pump and hydrostatic pumps have swashplate angle sensors to monitor and even out the pump stoke to obtain equal flow to both motors. Thus only 1 speed sensor is used to read ground speed for speedometer.

 

[Jabonee]

'A' Model. Yes it should have it.

 

[oldphart]

well i am back and with the same machine. the dealer still owns the machine they took in on trade and the hours have just barely increased. they have been passing it around from one location to the other and each shop bypasses trying to fix the issue and give it to the next. "it isn't at a bobcat dealer either by the way" they are considering selling it to me as is so i need some advice on possibility of repair costs from the most simple to the most expensive. it is a 2003 model by serial number with around 700 hours on it. i have traced it back to the original owner and the story sounds accurate and it is still within 100 miles of it's original destination. any opinions are welcome Thanks

 

[Jabonee]

The best thing to do is get it to a Bobcat dealer and plug it in !!! It could be a $50 switch or a $1000 controller. If you could state what exactly its doing and not doing when the issue Coors that would help a lot. Getting the codes when it failed would be the best.

 

[oldphart]

The best thing to do is get it to a Bobcat dealer and plug it in !!! It could be a $50 switch or a $1000 controller. If you could state what exactly its doing and not doing when the issue Coors that would help a lot. Getting the codes when it failed would be the best.

Thanks and i agree but i have to deal with this equipment dealer for a purchase price first. i began late last year and the dealer wanted to repair it before they sold it. in fact they did sell it and had to refund the customer and go get it because of this issue. since then they began passing it from one location to another and i wrote it off because they couldn't get anyone to sell it. now fast forward and it is still in there system back at the location that took it on trade and they tell me it need a new transmission. i asked them to quote me a price as is and the salesman acted interested but now has disappeared again so i think something fishy is going on.