Cat 320B LL Forestry Swing Machine Hyd Lockout

[BrianGrenier]

No travel, no boom, no swing issue:
First and before the hydraulics locked out,
I replaced the starter as the starter brushes and commutator fried themselves with all systems good at the time, electric system was charged to 24.4+- no issues anywhere, great batteries.
So the starter went in just fine and the machine started with the first spin of the key,
then
I put the yellow hydraulic safety lock down at the left armrest and not much happened. The controls acted like they were ready to work, I could get some boom down and it seemed to want to boom up, but no...
Putting the safety lock down makes the hydraulic lines shake as pressure seems to rise.

Looking at the schematic, I see there is a hyd loc solenoid 111-4871

1999 caterpillar 320 B LL processor serial number 9Js00308

 

[BrianGrenier]

Additional Information is the schematic attached has a reference to 121-149 Solenoid - Hydraulic Lock

and
143-1586 Hydraulic Lock Selonoid at location G (Location G is not readily apparent on the schematic)
What and where should I look for the issue...On another thread, someone with a telehandler had a lockout hyd with the issue located near the starter. Is that a clue for this machine?

There are no error codes on this 20k hour machine that has by-passed some electronics with a manual fuel/throttle cable.

 

[Nige]

A couple of clarifications.
111-4871 is a relay (one of eight) located in the circuit breaker panel group.
143-1586 is the main wiring harness.
According to the schematic the solenoid for the implement lockout appears to be 121-1491. Directly below the table of the machine locations for all the components on Page 1 of the schematic is a diagram of the platform marked "Area G". Is the implement lockout solenoid #1 on that diagram maybe..?

 

[Nige]

This is where the pilot manifled is located (#63) on the pilot lines. The solenoid valve 121-1491 is #4 on the 2nd illustration. And before you ask the other three solenoid valves immediately adjacent to it are different part numbers and (I would imagine) are not interchangeable for the purpose of diagnostics unless someone knows different.

 

[TVA]

If solenoid will check out OK, see if you have power to it when you trying to swing, if not check the pressure switch.

 

[BrianGrenier]

The cab isn't lowered every day on this machine, so it's worthy of a picture

It looks like I have located the 121-1491 solenoid in Area 'F' the back right of the machine, and as area H-1 in the schematic. 121-1491 would be the solenoid to the far left in the first picture and item #4 in your previous post. Does that sound right?

Larger image below:


Underside of cab, clearly visible after lifting the cab - Area 'G', didn't have anything other than connections harnesses.
So it seems the other Hydraulic Lock Solenoid Relay is at the armrest, does that seem about right?

 

[TVA]

The micro switch is actuated by arm rest, which in turn should energize coil on relay, and relay should allow current to go through its contacts and energise coil on solenoid. But you can start by checking weather you have power at solenoid with test light.

Another thing, sometimes equipment manufacturers have wires for controls connect not at battery + but at starters main power lug, you sure you connected all the wires at the starter?

 

[John C.]

If this machine has the flip up wand on the left side console that kind of prevents you from leaving the cab with control hot, then the micro switch is in that console behind the wand. I seem to remember it being behind a piece of plastic that you look at when you open the door.

 

[BrianGrenier]

Starter looks like all wires are connected.
Flip up wand has contacts that are audible as the wand is lifted.
The Solenoid 121-1491 Was under the cab, lifting the platform revealed it in the front left underneath.


That Solenoid makes a chunk sound as the wand is lifted and the hoses vibrate at the same time.
https://drive.google.com/open?id=1tu1LK-FFLCI8dGWEWmg37S3vLUu0dAO3

This machine was pressure washed about two months ago.
The plugs on the piping at 'F' are oily, as shown in the picture. I sprayed a lot of electric contact cleaner, but no connection yet.



So, I need to have a question here...How do you check the solenoids with the small contacts in awkward places to access.
Is it a idea to buy a plug from the dealer so that I could have a pigtail?
There are adjustment screws on the solenoids at area G1 and F4.

 

[TVA]

On those sockets it should be possible to remove orange weather boot by pulling small tab on top of the socket, try not to jam anything in there in fear of spreading contacts.
I would try and backprobe with taylors T pin, be careful not to touch pins to each other. You can try and Buy a pigtail from dealer, if they not gonna charge you arm and leg.

 

[TVA]

If that solenoid clicks, then you either got something stuck in it, or you for some reason lost your pilot pressure and it’s just coincided with your starter problems. Take the solenoid out and check the mechanical part of it.

 

[BrianGrenier]

Dealer is recommending at this point to check pressures at the pressure taps.

 

[TVA]

Sealer is right! Check if you even have a pilot pressure. On the CAT PD snap connector and 0-600 psi for pilot pressure and 0-5000 for main pressure gauges.

 

[BrianGrenier]

Here are the results from the pressure taps in the pump compartment, area F:
(1) power shift pressure = 400psi
(2) upper pump delivery pressure= 0psi
(3) lower pump delivery pressure= 0psi
Hydraulic oil was cold, the machine was at idle, the wand was 'down', system was closed.
Umm?

 

[TVA]

What do you mean upper and lower pumps? Can you post a pictures of them?

 

[TVA]

If your pilot pump is not piggy backing on the ass of the main pumps but sits separately on the drive housing- then it seems you lost your main pumps drive.

 

[TVA]

Let the CAT guys correct me if I’m wrong but as far as I remember this should be close center negcon system, it means you should have stand by pressure on both pumps at idle, I don’t think that you can loose both unloaders at the same time. So I would think something happened to your pumps drive so only pilot pump getting cranked!

 

[Bluox]

What do you mean upper and lower pumps? Can you post a pictures of them?

Have you ever seen a Cat 320 before?
Bob

 

[TVA]

I’m sorry, I didn’t look where you are located, it’s just CAT put weird things in their machines in East Asia and Oz. But your in the States so you should have A8VO in it. I don’t really know CATs but I remember that 315B has negcon with powershit.

BTW where are you in Evergreen state? I lived in Auburn 16 years

 

[BrianGrenier]

Here is a picture from the Service Information and pressure specifications.


(1) power shift pressure was 400psi
(2) upper pump delivery pressure was 0psi
(3) lower pump delivery pressure was 0psi

Attached is a pdf. Page 5 has the above picture.


So, how does one lose a main pump drive by changing a starter?