2485 Back hoe power check

[liberty2701]

It seems that the backhoe on my Dk50 seems to be lacking power especially on the piston that retracts the boom When I operate the lever i can hear a hydraulic noise coming from the control valve which I do not recall hearing in the past. How do I go about checking to see if the BH is getting adequate power?

 

[liberty2701]

I switched the backhoe to the A port. Seemed to work better. I

 

[BethelHntr]

Can you post a picture how you have the backhoe hydraulics attached to the tractor?

 

[liberty2701]

Can you post a picture how you have the backhoe hydraulics attached to the tractor?

I think i know what you are asking. I have the a/b port (either one can be used) and the return goes into the sump directly to the right. The vent tube is on the left

 

[murphy1244]

Can you give us a pic?

 

[liberty2701]

Can you give us a pic?

I am having trouble posting a picture. I am sure it is hooked up right. The return goes directly to the sump and the supply comes out of the a or b port. Is there an easy way to check that the hydraulic power through the back hoe is at max. It seems that i have to run it at 2500 rpm to get the power i need. Sometimes it feels lacking. Especially today i was curling a rock and it had trouble.

 

[liberty2701]

I got the photos to download. I added a couple extra for the second rear remote I added. I am wondering if somehow when I operate the backhoe it is crossing over into the other rear remote which I use to operate a root grapple. The reason I say this is because the fittings up front will drip(from the ball) when the system is under pressure. I thought maybe the fittings were bad so I replaced them with no change. Its is possible I am dropping some pressure through a crossover?

 

[Apsterbobed]

I have a similar problem with my hoe, also about a year and a half. The main boom sometimes struggles to lift a bucket of dirt and sounds like it's going into relief. Also noting stays put when I leave the ctrls for any length of time and I constantly have to push the feet down while digging. I was hoping someone would have some answers for you.

 

[murphy1244]

I was told when they add the second remote to use C or D port and drain at the fill like your doing.

 

[Apsterbobed]

I don't remember the port letter, I think A, but it's the top port on the set of remotes that has the detent (left set in my case). I have not tried using the other port. But the dealer didn't install the dump kit when they installed the hoe he said that there was no advantage to it. He gave me the kit and I installed it and have used it both ways if I know that someone other than me is going to use the tractor I don't use the dump because I don't have to worry about it getting deadheaded if they bump the levery the wrong way. I don't think I can tell the difference in either configuration, but next time I run it I will swap to B port and see if that makes a difference.

 

[murphy1244]

I don't remember the port letter, I think A, but it's the top port on the set of remotes that has the detent (left set in my case). I have not tried using the other port. But the dealer didn't install the dump kit when they installed the hoe he said that there was no advantage to it. He gave me the kit and I installed it and have used it both ways if I know that someone other than me is going to use the tractor I don't use the dump because I don't have to worry about it getting deadheaded if they bump the levery the wrong way. I don't think I can tell the difference in either configuration, but next time I run it I will swap to B port and see if that makes a difference.

The advantage to the dump kit is less heat build up. Make sure your quick connect is on right also.

 

[Apsterbobed]

I didn't think about heat, I was thinking it would run faster because of less restrictions on the return but that makes sense. As far as the quick connect being on right, I have the hoe on and off fairly often and I think I am seating the connections fully, also if you reverse the lines the hoe doesn't work at all.

 

[liberty2701]

This is an old post but I figured out my problem. Somehow, I think through the dealer. My relief valve setting got turned down on my backhoe severly limiting its power (that was the hissing). I adjusted it to the point were it kicks in just before the tractors relief valve kicks in. Now, my backhoe feels like the way it is suppose to. Lots and lots of power.

 

[VictorW]

On my KB2375, the bh relief valve adjustment was wired and set from the factory. After a few years, I noticed less digging force. Put a gauge on one of the bh hoses and saw the pressure was low with the relief valve opening to soon. Re-adjusted and all back to normal like yours.

Thanks for posting an update which may help others.

 

[JoelD]

Great post did not realize setting could possibly change with time

 

[Grant1]

Can you tell me how, Where is the valve and how do you adjust the valve. My 2485 also lacks power

 

[liberty2701]

Can you tell me how, Where is the valve and how do you adjust the valve. My 2485 also lacks power

Remove the top cover on the backhoe controls. On the left hand side you will see a valve with a set screw and locking nut. The set screw adjusts the backhoe relief valve pressure. I set mine to kick in just before the tractor relief valve kicks in. Ideally, you would want to you use a guage and set it but I think that is not neccessary.The backhoe relief valve setting is slightly lower than the tractors relief valve setting in the specs. As you adjust the set screw pull a backhoe control to deadhead the pump and you will hear the relief valve kick in. Set it so it kicks in just before the tractors relief valve kicks in. You can clearly hear it.

 

[Grant1]

Thanks for the info. I will let you know if it helps

 

[Grant1]

I turned the relief screw in about 1 turns. I am unsure as what type of noise that I am supposed to be listening for. I am hearing the tractor engine slightly bog. Is that the noise I am looking for because I had that before I adjusted the screw when the backhoe lever was deadheading. The backhoe seems to have a little more power but nothing really noticeable

 

[JoelD]

You are listening for when the oil is directed through the relief valve

If the oil did not divert your engine would stall or something would break

When you pull a lever the oil is directed to the piston when the piston can no longer move as it hits its limit of travel or an immovable object the oil builds pressure and something needs to give either the piston blows a seal and oil goes to atmosphere or the pump breaks and blows a seal or shears the impeller or the motor stalls etc

Instead there are relief valves that once a predetermined pressure is hit something around 2000-2500 psi the oil is passed through the relief valve and on its way back to the reservoir

It is this diversion you are listening for

Should be right around the time the motor boggs to a certain point and Boggs no further

Really best to do this with a gauge

Joel