540 problem

[cavedweller29]

Hi all, I just bought this machine and I am wondering if I bought some problems too. I have had it for 3 days and I have used it around the house for several hours with no problems. Today...I found that I couldn't leave well enough alone and I decided to clean out the engine compartment. It had accumulated several years of dust/oil mist/mud so I used brake cleaner to wipe off the gunk, I pulled the engine shroud off and cleaned the cooling fins and I greased all of the pivot points. Now, it runs fine but the transmission warning light does not go out after the engine is running. The only questionable thing I did was to rotate the engine (by hand) both clockwise and counter clockwise several times while trying to better access the gunk behind the flywheel. Could this have messed up the pump? If so, where should I start in repairing it and if not, does anyone have any ideas? Thanks in advance, Glenn

 

[OldMachinist]

About the only thing I can think of is that maybe you knocked the wire off the sending unit while you were cleaning. The sending unit is normally in the block the hydraulic filter screws to so thats where I'd start.

 

[cavedweller29]

About the only thing I can think of is that maybe you knocked the wire off the sending unit while you were cleaning. The sending unit is normally in the block the hydraulic filter screws to so thats where I'd start.

Thanks for the response. That was the first thing I thought of and I checked the wires. They were attached by spade connectors so I pulled them apart, cleaned and reconnected them (just in case) for both the temp and charge pressure sensor but the light stayed on. Would turning the engine the wrong way do anything to the pump or replenishing valve?

 

[Tazza]

Thanks for the response. That was the first thing I thought of and I checked the wires. They were attached by spade connectors so I pulled them apart, cleaned and reconnected them (just in case) for both the temp and charge pressure sensor but the light stayed on. Would turning the engine the wrong way do anything to the pump or replenishing valve?

Turning the motor by hand wouldn't have caused any damage.
I'd look at possibly replacing the sender, you never know, you may have had bad timing for it to fail when you were cleaning. You can even throw a pressure gauge to see what the charge pressure is, it should be about 90-120 PSI

 

[cavedweller29]

Turning the motor by hand wouldn't have caused any damage.
I'd look at possibly replacing the sender, you never know, you may have had bad timing for it to fail when you were cleaning. You can even throw a pressure gauge to see what the charge pressure is, it should be about 90-120 PSI

Thanks Tazza...I played with it for a while today and I am even more confused. I tried disconnecting the temp sensor and found that the light came on when started and then went right back out as it should. I figured that it was the temp sensor so I hooked everything back up for the time being until I could pick a replacement sensor up after the holiday. I went out to do some work this evening and found that the light was on, which I expected because I hooked the (faulty?) temp sensor back up. I then found that when in reverse or while lifting a loaded bucket, the light went out. The light stays on for all other forward movement and for any empty bucket operations. The only thing I can relate both of those things to would be a problem with the high pressure replenishing valve. I also have no idea why the problem goes away completely with the temp sensor disconnected. Any other suggestions? I'll check the charge pressure tomorrow morning too. Thanks in advance.

 

[Tazza]

Thanks Tazza...I played with it for a while today and I am even more confused. I tried disconnecting the temp sensor and found that the light came on when started and then went right back out as it should. I figured that it was the temp sensor so I hooked everything back up for the time being until I could pick a replacement sensor up after the holiday. I went out to do some work this evening and found that the light was on, which I expected because I hooked the (faulty?) temp sensor back up. I then found that when in reverse or while lifting a loaded bucket, the light went out. The light stays on for all other forward movement and for any empty bucket operations. The only thing I can relate both of those things to would be a problem with the high pressure replenishing valve. I also have no idea why the problem goes away completely with the temp sensor disconnected. Any other suggestions? I'll check the charge pressure tomorrow morning too. Thanks in advance.

You will find the temp sender and pressure senders are tied together. If its over temperature or under pressure the light will come on. It appears your temp sender may be shorted out...

 

[cavedweller29]

You will find the temp sender and pressure senders are tied together. If its over temperature or under pressure the light will come on. It appears your temp sender may be shorted out...

Thanks again Tazza, I'll check the charge pressure tomorrow and if that is fine, I'll pick up a temp sensor on Tuesday.

 

[cavedweller29]

Thanks again Tazza, I'll check the charge pressure tomorrow and if that is fine, I'll pick up a temp sensor on Tuesday.

Hi all, Just to let everyone know the outcome, it was the transmission temp sensor causing the problem. I bought a new one and installed it today. Upon closer examination, the tab where the wire attached had corroded through over the years. When I cleaned it the other day I moved the wire just enough that it broke the connection. It looked fine and it tested fine to the screw but, the connection was broken on the other side. Thanks for the guidance.

 

[Tazza]

Hi all, Just to let everyone know the outcome, it was the transmission temp sensor causing the problem. I bought a new one and installed it today. Upon closer examination, the tab where the wire attached had corroded through over the years. When I cleaned it the other day I moved the wire just enough that it broke the connection. It looked fine and it tested fine to the screw but, the connection was broken on the other side. Thanks for the guidance.

Glad its up and running again!
Something so simple.