All, Not even sure what the light is ... there are 2 warning lamps on the right side of the cab ... the one that is flickering on my skid steer is the one on the far right side ... the lense of the light looks like a gear or sprocket ... i'm guessing this is a hydraulic warning light. Raising and lowering the boom or curling the bucket does not trigger the light ... but driving does, it flickers some when going forward but is on more consistantly on when going backwards. Please don't tell me its a pump ... could it be clogged filter ... hasn't been too long since i changed the filer and fluid. Any help on what this could be or how to troubleshoot it is greatly appreciated, Roger
Help Support SkidSteer Forum:
OldMachinist
Well-known member
- Joined
- May 24, 2006
- Messages
- 2,748
The warning light with gear on it is the transmission warning light. There are 2 things that can trigger it, low hydrostatic charge pressure or high hydraulic oil temp. Most likely its low charge pressure and could be a bad sending unit. To check the charge pressure remove the sending unit and install a gauge that will read up to 200 psi. Run at full throttle for testing. On machines with serial number 14999 and below the pressure should be 140-170 psi. For newer machines its 95-115 psi.
On a 843 it can be a clogged filter in the engine bay also. Unsure about the 743? When were your hydraulic filters last changed? Does it have one or two. Does your hour meter work? The hydrostatic charge pressure switch has a NC contact (for low pressure warning) and a NO contact for providing ground to the hour meter. If you do not know the maint. history of the hydraulic filters, I would change them first.
I changed the filter and fluid about 50 hours ago .... the only filter I changed was in the engine bay ... is there another hydraulic filer somewhere in the plumbing ... I was not able to find one seems like I remember hearing of another filter somewhere. This 743b was new in 91-92 I beleive. Thanks, Roger
skidsteer.ca
Well-known member
- Joined
- Jan 20, 2006
- Messages
- 3,853
On the 743 ( not a B model) the trans light wire, (yellow wire runs to the top of the main pump to the charge pressure sender, and then over to a temp sensor on the rh side inside the frame, and also to the temp sersor on the hydraulic filter) was worn through the insulation and getting a ground from the frame intermittantly causing the light to flicker. In my case it was pinched by the cab (being closed) right at the base of the hydraulic tank. Run the engine with the cab up then see if you can wiggle the wire around noting when it tends to trigger the light.
Ken
I haven't had a chance to check anything yet ... but the more I think about the more I'm beginning to worry its a pump since the light seems to be on almost constantly when backing up (on but not as much when going forward) ... I would think if it was a sensor or a shorted wire it probably wouldn't be specific to a certain action (backing up). Anyway, does anyone have a suggestion as to where I can find a test gauge and what readings I should see. I should also mention that about 50 hours ago I had to rebuild one of the drive motors ... I didn't notice any shredded metal, only torn "soft" seals ... I was hoping that wouldn't cause more and expensive problems down the road but now I'm wondering. Thanks, Roger
You will need a pressure gauge that reads abour 150psi. Surplus center has them, as would other places. You will need an adaptor for the port on the pump.
Its possible the other motor is leaking too. If the seals are crumbling, it may be allowing a little more oil through the case drain that is lowering the charge pressure.
Confirm the pressure is right first. The senders do go bad.
If there are no horrible noises or a feeling something is biting at the steering levers, it should be ok. I found that when my trans light comes on when using my 743, it feels like something is grabing at the steering levers, a horrible feeling. Its rare, the machine needs to be hot and when i'm doing a quick curl of the bucket.
I got a chance to work on the skidsteer a little today. I unpluged the wire at the filter and no change. Opened the cab to get to the sending unit on the pump, there are two wires coming from the sending unit ... 1 was routed with several other wires into a corrugated wire loom. However, I notice the other wire laying in the transmission linkage area and its not connected to anything, but as I said the naked end was laying amongst the linkage. It evidently was "pinched" to ground when the linkages were pulled into the reverse position ... hence, the light was on almost constantly when going in reverse ... I insulated the naked end of the wire and now no more light. But now, I am wondering where this wire should be connected .... is it more likely the wire for charge pressure or is it for oil temp ... does anyone no how I can determine which it is and where it belongs. Thanks, Roger
I think it should be on the sender.
When you turn the key on, does the light come on? It should have two lights on, one for hydraulic oil pressure, the other for the engine oil. When it starts, they should both go out.
I believe the charge pressure switch has 2 contacts and the temp switch has one. You cannot reverse the contacts on the charge pressure switch as one is a NO and the other NC. Thats indicated on the switch. Easy to see on a new switch, maybe hard to see on an old switch. If your hour meter works properly and the trans light come son with key on engine off, then its a wire going to the temp. Both warning lights should come on with the key on engine off. If not, first check the bulbs. In my used 843 I replaced both bulbs, the charge pressure sender, fuel sender, and all 3 gauges. All of the gauges had sawdust in them and were marginal.
