Transmission light

[turbomoparboy]

I have just about finished fixing my 94 763 and installed new oil pressure / transmission lights in the cab because the original terminals corroded away on the lights so they did not work. When I started it, the engine oil pressure went off but the transmission light stayed on. It was about mid 40's F. I let the machine idle and the light stayed on for about 5 minutes then it went off. if I would increase the engine speed it would come back on then after a minute or 2 go of at this speed and so on. I am going to change the filters and hydraulic fluid this weekend ( the filter by the engine has been on ther for over 10 years and 600+ hours, it sat for years ) Is there anything I should look for when I change the fluid? The machine has just shy of 4000 hours on it. I don't hear any strange noises and everything operates correctly. I have the big filter next to the engine and 2 other silver "inline" filters which I am assuming are the drive motor filters. Thanks! Justin

 

[donald73d]

You should look at your manual (owners or service) for the electrical schematic and see what you have in the way of senders in the hydraulic system. In my 843 I have a filter plugged sender near the big filter in the engine bay, and a hydraulic charge sender on a tee near the main pump and a temp sender not far from the hydraulic fluid reservoir. The charge sender also provides power to the hour meter. It has a NO and a NC contact. I would replace the large filter by the engine and see if it solves the problem, it did for me (well one of them anyway). Get a Bobcat filter or get the latest Bobcat filter number from the dealer (they may have changed, mine did) and cross reference that number to a NAPA or WIX. But best with a Bobcat. Bobcat was less than a NAPA, when I checked. But that big filter is in the $50 price range. The WIX listing for my Bobcat (by model) had a smaller length filter than the newer one specified by Bobcat, so it looks like WIX never realized that Bobcat changed the part number. (Mine is a 1990s Boibcat, so if WIX has not figured it out by now, I doubt they ever will). In my case, when I replaced the trans warning light, it would not come on with Key-On Engine-off but would come on with engine running. Replaced the large filter in engine bay (prior owner had a WIX in there) with the correct Bobcat and the trans warning light did not come on with engine running. Replaced the hydraulic charge sender and the light comes on key-on engine-off and goes off after the engine starts (but not as quick as the engine oil light goes out). Did I mention to get Bobcat filters?

 

[7LBSSMALLIE]

what you did not mention was is a boss led right hand upper. mostr likley cause is sender but for conformation is it real or indacteded to be sure you need to check actual preesures. i would replace sender , most likley cause. if you do have actual low chargre press you got bad shit going on. needs to be addressed, possible faliures that can occur from low charge are stat hyodryastatic pump. or motors/ dont freak out probally sender. chang it(will not look like the one you removed will come with harnees. and take note there is another plug that will hook up really close. if it got plugged up it sent 12v to sender smokin it/ that was the differnce between boss and standered, so new sender if got plugged wrong is done

 

[turbomoparboy]

what you did not mention was is a boss led right hand upper. mostr likley cause is sender but for conformation is it real or indacteded to be sure you need to check actual preesures. i would replace sender , most likley cause. if you do have actual low chargre press you got bad shit going on. needs to be addressed, possible faliures that can occur from low charge are stat hyodryastatic pump. or motors/ dont freak out probally sender. chang it(will not look like the one you removed will come with harnees. and take note there is another plug that will hook up really close. if it got plugged up it sent 12v to sender smokin it/ that was the differnce between boss and standered, so new sender if got plugged wrong is done

I replaced the 3 hydraulic filters with bobcat filters and replaced the oil in the resivor ( about 6 gallons) with Shell Donax TD 10w30 tractor transmission / hydraulic fluid. The light now goes off almost immediately after starting the machine. I think the previous owner was using 15w40 engine oil in the hydraulics because it seemed a little thicker than the 10w30 I put back in. This may also have been the reason the light was on until it warmed up. Thanks for the info.

 

[HarryN]

I replaced the 3 hydraulic filters with bobcat filters and replaced the oil in the resivor ( about 6 gallons) with Shell Donax TD 10w30 tractor transmission / hydraulic fluid. The light now goes off almost immediately after starting the machine. I think the previous owner was using 15w40 engine oil in the hydraulics because it seemed a little thicker than the 10w30 I put back in. This may also have been the reason the light was on until it warmed up. Thanks for the info.

Turbo.... there's no way the 15w40 would have been the problem. So if you got it fixed, it must have been the filters (in your case) Good job.

 

[donald73d]

Turbo.... there's no way the 15w40 would have been the problem. So if you got it fixed, it must have been the filters (in your case) Good job.

What brand filters were the previous ones? Same physical sizes?