JD 310C has no steering

[Syleng1]

Hello all- kinda new posting here but I’ve been reading your material for years. Really good stuff here for sure.

So I’ve got a JD 310c backhoe.
Steering just stopped working after shutting off the machine for lunch.
I first dropped both lines to the steering cylinder. Very little pressure either direction when the machine was running and I turned the steering wheel. I then pulled the supply pressure line to the steering valve- very little pressure and flow. The wheel just spins either direction with no stops. (I thought there should be a stop in either direction.) I pulled the top steel fuel tank cover and got into the priority valve and inlet pressure seems low but I’ve got flow. Same flow or a tad lower coming from the outlet side going to the steering valve. I do not have a pressure gauge yet- need to buy one. I believe it should be like 1000-1500psi. Anyone have a manual to check that spec for me?

I followed the priority valve pressure line right back to the pump off the front of the engine. The pump was replaced about 10 years ago or 1500hrs ago from John Deere. With out pressure gauge, I’m spinning my wheels and can’t see straight. Can someone help me see the forest thru the trees on this one?
Too many parts to take apart - and replace and “Guess.” Makes a costly mistake.
thank you,
Joe

 

[jimg984]

you didnt say you checked fluid lever,, filter,,, yes, when low in fluid the steering wheel will keep turn in either direction,,, that part should be ok once you fill back it back GL

 

[Syleng1]

Thanks jimg984- The fluid level for the steering is the same tank for the hydraulics. The level is full.
The PS pump piggybacks off the main pump and is fed thru the same supply line. The hydraulics on the machine work fine except for the PS. Filter is new John Deere like 40 hrs ago. New fluid as well from John Deere.

 

[mg2361]

Serial number please.

 

[Syleng1]

JD 310C Back hoe
Unit Vin# T310CF733992
Engine serial# TO4239D152469
Engine. Number: 4239DT003

 

[Bls repair]

Steering shaft connections all good?

 

[Syleng1]

Yes. Steering shaft seems to be turning the steering valve. If I turn it left on steering cylinder hose dribbles fluid and if I turn the steering wheel right the other hose dribbles. I have yet to remove the wheel shaft from the steering valve.

 

[mg2361]

If you have pressure gauges or know someone with some you really need to check steering pressure. If gauges are not available then check the load sense hose and fittings between the steering orbital valve and the priority valve (see below).

 

[Syleng1]

I ordered a good set of gauges and they should be in on Friday if all goes well.
I looked at the picture but my steering valve has 4 fittings on the right side (sitting on the drivers seat) one is pressure from the priority valve, one is return to tank and 2 go to the steering g cylinder.
I’m looking for numbers or pressures or even a Print from the FSM about this.
Thank you to all who have helps thus far.
Syleng1

 

[mg2361]

There should be a fifth hose that goes back to the priority valve. That would be the steering load sense line. That is how the priority valve knows the steering is commanding oil. The fitting that comes out of the steering valve for that sometimes gets debris in it preventing pressure from going to the steering valve.
To check the steering pump pressure, install a gauge at the "T" port shown below. With oil warmed up and engine at fast idle, stall the backhoe boom up function and read your gauge. Should be 2950 - 3200 psi. Post the results.

 

[Syleng1]

MG2361- NOW THAT'S What I was talking about!

As soon as the gauges come in I will pull pressures and let you know.
Thank you for this information. I greatly appreciate it.
Syleng1

 

[Syleng1]

So I got my hydraulic gauge kit that has specifically "John Deere" as a fit ment guide.
I guess the machine is too old and does not have quick disconnects for the gauges.
Need a few days to put together a couple to fit and will return back with the results.
Thanks for your patience.
Syleng1

 

[Syleng1]

Okay- finally returned to the machine at my back property. Work has been crazy- my machines last to get love:

Screwed in my gauge to the above mentioned fitting(pump supply fitting “t”)

oil cold and leaving steering wheel alone I have 333-400psi.
Turn the steering wheel and we jump to 1300psi- with oil temp increase to running temp- The pressure lowers a little bit (100psi)
When you turn the steering wheel zero movement in the steering cylinder and the steering wheel has no stops- just keeps turning and turning unlimited. Left or right.
I checked the feed back hoses and they seem to be clear. Fluid flowing between priority valve and steering gear.
Any ideas?
Syleng1

 

[mg2361]

What pressure do you see if you hold the backhoe boom raise and loader boom raise at the same time?

 

[Syleng1]

I did not get that far and had to run to pick up my son from school. I’ll check possibly tomorrow during lunch. sorry.

 

[Syleng1]

Finally got a good uninterrupted day-

screwed gauge on. Engine warm and running outside temps are 65degrees.
Hydraulic oil is warm
Gauge reading 2,000psi + or - 100psi
While the boom and the stick are both moving from rest position up.
When both sticks hit the stall position my pressure jumps to 2800 psi.

I tried multiple time. Giving the pump a rest between running with no load.
2 times 2800psi. 3rd time pressure spiked to 3,000psi but dropped to 2800 psi after 5seconds.
I’m going to take apart the Sense line to see if clear or clogged.

 

[Syleng1]

I removed the sense line at the priority valve side.

engine running it had a little flow out of the priority valve side. But turning the steering wheel I had drag in the wheel like the hydraulics were working and a steady 1/8” flow from the hose- telling my the hose is not clogged - that direction at least and even though I had no wheel movement the steering wheel had drag since this whole thing started.
As soon as I reconnected the sense hydraulic hose to the priority valve I turned the wheel and 1/4 turn of the wheel and I lost all drag.

without a pressure flow gauge I’m just not sure I will test results f issue is in priority valve or steering valve.

 

[Syleng1]

Took the priority valve out and disassembled looking for brass filings from pump. Nothing. Clean as a whistle.

 

[mg2361]

I believe you may have an issue with the relief in the steering pump or an issue with the load sense relief in the priority valve.

 

[Syleng1]

Mg2361-
Yes spool moved easily. Upon reassembly it took a few tries to get it to go back together- but once it did it slid right in.

the spool to the right moved very easily.

after testing with pressure gauges I believe the pump is good at 2800psi
I took out the steering valve already. I want to disassemble but Need a few days to get back to it.
In order to get to pump to check relief I have to remove counter weight. I cannot get my smaller machine back there until ground refreezes due to muddy conditions. I will loose any wheeled machine currently - weird high temps for New England right now. My Ex120-2 will get back but she’s a bit awkward for getting a counter weight off at that angle lol! Good for digging but tough for fine picking.

The original issue was the machine ran fine. I shut down for lunch and when I started it back up no steering. I’ve had things get hot and bind before but never quit like this. Those rotary steering valves are not my strong suit. I can access the machine by foot. But I have the rotory steering valve in my shop. Thank you again for the help. Joe