2004 NH Backhoe LB75.b - Weak hydraulics, no steering - Is it the pump?

[Cogniz]

Hey y'all.
New to me NH backhoe. Runs and drives perfectly, except for the steering, which is like wrestling a bear.
Hydraulics will create a tiny bit of pressure, rolling the loader bucket up, and about 6" of movement in the Extendahoe up and down.
That's the good news, NO lifting of loader, no boom, stablizers don't go down, and again, no steering help to speak of.
I've been buried in the Service Manual. Seems to me the pump is bad but I would LOVE a second opinion.

I did stick my arm down into the Reservoir and did not feel any obstructions on the suction or return line. Note that there is NO screen down there..weird, eh? It was clean overall and the fluid looks good and is above the sight glass.
I changed both hydraulic filters. The big one that recircs to the tank, and the little one just forward of the big one (no idea what that one is for).

Today I'm going to drain the tank, disconnect the pump suction hose, and make sure there is not blockage.

Given the NH has a single pump with 2 parts (front pump, back pump), with Steering given priority, I cannot figure out if there is a Service Relief that would not allow any pressure to build.

Any wisdom is very much appreciated!!!

 

[aighead]

Nice looking machine, I have the same one but mine had about a thousand more hours on it. I hope it's something easier than the pump! Sorry, I don't have an answer for you.

 

[NH575E]

Sounds like you bought yourself a problem if the screen is missing and weak hydraulics. Not sure you could reach or see the suction screen from the top but I'm not that familiar with the LB75.

You should be on the right track to drain and open the tank and supply for inspection.

EDIT:: Looks like the LB75B doesn't have the same reservoir and screen the E series has. Does it have a access plate on the side of the reservoir?

 

[NH575E]

I'm seeing a check valve in the filter line you might want to check.

Under Hydraulic/Filter Assembly and hose to return manifold.

New Holland Parts | Buy Online & Save

New Holland Parts from Messick's, right priced parts service with knowledable New Holland parts technicians. Shop online or call our Parts Hotline.

www.messicks.com

 

[Cogniz]

Sounds like you bought yourself a problem if the screen is missing and weak hydraulics. Not sure you could reach or see the suction screen from the top but I'm not that familiar with the LB75.

You should be on the right track to drain and open the tank and supply for inspection.

EDIT:: Looks like the LB75B doesn't have the same reservoir and screen the E series has. Does it have a access plate on the side of the reservoir?

No sir, no screen and no access plate on the side. The top cap is mounted on a bolt down access plate however.

and to your point, no suction screen shows on the drawing. I played proctologist to both suction and return lines and they were clear.

 

[Cogniz]

I'm seeing a check valve in the filter line you might want to check.

Under Hydraulic/Filter Assembly and hose to return manifold.

New Holland Parts | Buy Online & Save

New Holland Parts from Messick's, right priced parts service with knowledable New Holland parts technicians. Shop online or call our Parts Hotline.

www.messicks.com

I’ll check that tomorrow. good catch.

 

[Doc Russ Miller]

I’ll check that tomorrow. good catch.

Did you ever get a solution to the problem? Having simular issues with a 2002 LB75

 

[Cogniz]

Closing out the saga. Did everything I could to rule out the pump. But it was the pump.
Messicks could not find one, anywhere. On a whim, my sales guy called NH Europe. They found a pump in Australia! NH North America only charged me overnight shipping from Messicks to me in TN. Incredible service.My theory is that this backhoe was a cinder / salt loader in lower NJ. And they broke the fill cap / vent on the hydraulics and some cinder or salt got into the oil.I cut the filter open and, well, there you go.
I replaced the pump, vacuumed and wiped out all the oil I could but did not purge the lines. Of course put in the large and small hydraulic pumps.
Back in business. This has been a great unit so far. Now I'm dealing with a sticky throttle at the injector body connection. That's going to be another post.

For reference, this is an Italian pump. It's made by Casappa. That part number is 79930050

In September, 2023, right after Messicks solved the problem for me, I found one in LIthuania...here's the email exchange-

I can offer this hydraulic pump.
Part number 85826147 - 1450 Euro.
Transport to Dayton, TN USA - 485 Euro.
Total 1935 Euro.

Best regards

Evaldas Jucevičius
Sales manager

TECH4S UAB
Vingių str., Padvariai, Kretinga district
Lithuania LT-97157

 

[HarleyHappy]

Thanks for the update