Backhoe 758C backhoe ??????s

[viperman]

Hello, I have the above backhoe and for some reason it feels weak when moving side to side and trying to dig. It just seems to run out of umph. It does make a high pitch sound(like trying to squeeze alot of liquid in a small tube) when loaded. The stabilizer arms will barely pick up the tractor. I have not checked the oil level being that I just picked it up at the dealer (brand new) Any Ideas????

P.S. The loader seems to be weak also.

Also the left boom controller seems to stick when going down only.

 

[pekabu]

I have a 756c and left to right is fast, but not very powerful. As for picking up the back of the tractor it does it fairly easily. I believe if you push the left stick all the way forward it goes into float mode. So it should stick, but after you push through the detent.

 

[PineRidge]

Mine is a 757C and the stabilizers will lift the rear wheels of the TC-40D off the ground easily. I can drag the tractor using the boom itself to relocate the tractor. I normally run my backhoe at about 2100 RPM, if I go any higher on the RPM range boom movements can get jerky since they tend to move quicker. I only hear noises when I try to move an immovable object and the relief sounds off. (high pitch whistle)

If your problem exists with your loader as well you may have a problem with your relief valve. There are ways to check the internal hydraulic pressures.

 

[Propertymaint]

I have the 758C on a TC40D. I agree with Pine Ridge, have the relief valve checked. I also use the backhoe to move my machine around when I'm in tight spaces. The stabilizers and hoe should be capable of lifting the tractor. The swing on a backhoe typically is meant for swinging away dirt from a trench and not to grade off a 2ft berm. But you may have a problem with the pressure setting of the relief valve. Depending on where and what I am digging, I run mine between 1600-2000 rpm. It will give all the power the tractor is going to give without destroying it and gives a decent speed. Let us know how you make out. Also, the boom has a float position if you push the lever all the way forward. That is why it appears to be sticking. Takes a little to get used to.

 

[viperman]

Where is the relief valve located? And can I turn it up myself?

 

[PineRidge]

Viperman if it were me before I started tweaking the relief valve I would first find out what the internal pressures were so I might have a base line. Have you checked the pressure to see where it's at now?

I believe that New Holland tractors equipped with SuperSteer are considerably higher than those without the same option.

Non-SuperSteer Models TC35 through TC-45D are 1450-1520 psi (100-105 bar)
Supersteer Models TC-35 through TC-45D are 2030-2100 psi (140-145 bar)

 

[RickB]

I won't quote pressures off the top of my head, but ALL 40's and 45's are the same regardless of front axle. 35's MAY be a little less, but nowhere near 650 psi less. The high end pressure you posted is close, the rest are way off.

 

[PineRidge]

Guess I could be wrong but the pressures that I posted were listed as relief valve pressures in my New Holland repair manual section 25-3. The manual is the same for all Class III TC models.

Maybe those increased pressures are one reason folks with the SuperSteer option are not as opt to notice this type of problem.

 

[jinman]

</font><font color="blue" class="small">( Non-SuperSteer Models TC35 through TC-45D are 1450-1520 psi (100-105 bar)
Supersteer Models TC-35 through TC-45D are 2030-2100 psi (140-145 bar)
)</font>

PineRidge, those pressures sure sound familiar. Are they the power steering pressures? Did you look at the correct line in the table? Power steering pressure is the only thing I'd expect to be different for a Supersteer tractor. I can't imagine why the main hydraulic pressure would be set different. I think they are all around 2000 psi as RickB stated. /forums/images/graemlins/confused.gif

 

[PineRidge]

<font color="blue"> PineRidge, those pressures sure sound familiar. Are they the power steering pressures? Did you look at the correct line in the table? Power steering pressure is the only thing I'd expect to be different for a Supersteer tractor. I can't imagine why the main hydraulic pressure would be set different. I think they are all around 2000 psi as RickB stated. </font>

Whoops, It looks like I did quote power steering pressures Jim. Sorry! /forums/images/graemlins/blush.gif

Under hydraulic lift system pressures I am showing the following for system relief valve setting:

2275 PSI for a TC35
2500 PSI for the TC40
2500 PSI for the TC45

 

[RickB]

Now you got'em. Also, the 758C hoe has its own relief valve which is set at 2150 PSI. This does not affect the loader or other tractor functions

 

[viperman]

Anyone have a pic of the relief valve???

 

[PineRidge]

Rick this just keeps getting better and better. I'm showing a total of 3 relief valves (circled) in my 757C control block breakdown.

With your position I'm sure you already knew that.

Relief #16 Work port. is set at 2500 PSI
Relief #17 Anti Cav. is set at 2000 PSI
Relief #18 Main is set at 2000 PSI

 

[PineRidge]

Viperman do you have any rear remotes on your rig?

 

[viperman]

I think I have one that the backhoe is plugged in. Sorry I am NEW to tractors.

 

[PineRidge]

Viperman I think your backhoe is connected to your power beyond port not a rear remote.

Your first post indicated that you have a 16LA loader. If I was going to make this test I would first start and operate the hydraulic system to warm the hydraulic fluid to normal operating temperature. I would then park and disconnect my loader to get it out of the way and make access to the loader quick connects easier to reach. I would then use the top high pressure hydraulic quick connect that normally connects your front end loader and connect to a 1-3000 PSI pressure gauge. I would then start the tractor and bring it up to 2600 RPM and move the control lever to the bucket raise position, the pressure indication on the gauge should show 2500 PSI for your TC-45D.

Watch that hose hooked to the pressure gauge because I'll bet its going to get stiff when the pressure hits it real quick. Or why not just have your dealer perform the tests for you and you won't be out the cost for the pressure gauge.

 

[DK35vince]

</font><font color="blue" class="small">( ( Rick this just keeps getting better and better. I'm showing a total of 3 relief valves (circled) in my 757C control block breakdown.

With your position I'm sure you already knew that.

Relief #16 Work port. is set at 2500 PSI
Relief #17 Anti Cav. is set at 2000 PSI
Relief #18 Main is set at 2000 PSI )</font>

Mike,
There may be even more than 3 relief valves.
Relief # 16-Quantity=2
Relief #17-Quantity=2
Relief #18-Quantity=1

 

[PineRidge]

Vince looking at the picture I do see two that I missed in the bottom of a couple of sections. Thats a slew of 5 relief valves on the backhoe itself.

 

[Chris527]

Hi Viperman,

This is probley not the fix but I took delivery of a new TC-30 with a woods 7800 Backhoe, I unhooked the hoe and did some brush hogging first. Two days later I hooked the backhoe back up and did notice noise and lack of swing and lift power, as you mentioned it was new so I never thought to check my hydrolic oil. Well I did and found it to be not even on the stick so I bet I checked 10 times before I came to the conclusion it was low. Called my dealer and they gave me a gallon of fluid and it took it all and then another quart. I guess they never ran the circuts and it scavanged my internal supply. After 5 quarts and some bleeding it ran fine. When they dropped the tractor off , they went over everything and The levels were fine then so I will never assume anything again. I have over 50 hrs on it now and it has been a great machine all around. Good luck with your problem.

Chris

 

[viperman]

I will check the fluid level when I get to go play with it. It is 40 miles away( I really need a trailer) I hate to take it to the local dealer because I did not buy from them. ( It would have cost me almost $8000.00 more). Thanks for the replys.