Cat 320B LL Forestry Swing Machine Hyd Lockout

[TVA]

Look at the return filter - if you will se debris in there - know that is only small portion of the debris, as this pump does not have a case drain and most of it laying at the bottom of the pump.

 

[BrianGrenier]

Look at the return filter - if you will se debris in there - know that is only small portion of the debris, as this pump does not have a case drain and most of it laying at the bottom of the pump.

Forgive me while I play Devil's Advocate on this suggestion. It's in my nature...

Everything when good when last shut down before starter issue.
After the starter was replaced the pump did not run, so no junk possible.

So that's that,
We might agree that Amps spiked when starter commutator melted. I also had a computer wiring issue which is maybe a clue.

 

[BrianGrenier]

Where did your starter switch go? Have you checked your pump controller fuses? Check the wiring harness under the cab especially where the cab hinges .
Good luck
Bob

The starter switch terminal on the new starter? I'm thinking it's visible in the picture...

 

[TVA]

Forgive me while I play Devil's Advocate on this suggestion. It's in my nature...

Everything when good when last shut down before starter issue.
After the starter was replaced the pump did not run, so no junk possible.

So that's that,
We might agree that Amps spiked when starter commutator melted. I also had a computer wiring issue which is maybe a clue.

Brian! This will be my last post on this thread unless you would want me to come back to it: based on the information you provided your pumps just NOT pumping anything! There’s a little chance that something happened to your regulators and for some reason they do not provide pressure on upstroke side of a servo piston but chances of that happening is extremely slim! At this point it looks a lot like what I’ve been saying in the beginning- catastrophic failure!
I’m sorry! God help and bless you!!!

 

[BrianGrenier]

TVA, absolutely I want you to come back on this one! You have a Lot of good ideas.

It's just that i didn't want to pull a filter out in the rain today and also picking a hyd hose to run open without a helper here in the woods isn't ideal.

It should be obvious that I don't know much about hydraulics.

I'm not ready to start pricing a new pump, not even goin' to.

But tossing this problem around is a good learning experience for me. Thanks for your input and Nige and Bluox and others who would like to come by and check it out!

So for now, I hoped we might ponder why if that solenoid (6) isn't getting power how is it regulating flow?

A slim chance of no mains pressure being wiring I'll take...

 

[BrianGrenier]

And John c was right that it is confusing, lol.

 

[BrianGrenier]

Anyone know where to get senr9291?
Systems Operation, Testing and Adjusting: Engine and Pump Electronic Control System : For the 311B, 312B, 315B, 320B, 322B, 325B and 330B Family Tracked Excavators. SENR9291

 

[BrianGrenier]

Hey CAT guys,
Tracing wiring from ecm and to the proportional reducing solenoid valve at pilot block, there's something called
Backup epr valve sw...
What would that translate to?

I read it as backup electronic pressure reducing valve switch.

It's a toggle...

 

[BrianGrenier]

Yep, that's the manual override for the proportional reducing valve which bypasses the ECM and in manual mode is selectable for rabbit or turtle.
In Turtle mode there would be an increase signal to the solenoid at the pressure reducing valve and a decrease in pump output.

 

[BrianGrenier]

The dealer didn't have information on what the amperage should be at the EPR valve...I measured about 1A with a Fluke clamp meter. 1A seems very low...

 

[Nige]

SENR9291 "Not Found" according to what I have access to.

 

[BrianGrenier]

SENR9291 "Not Found" according to what I have access to.

Thanks for looking!

I'm currently tracking wires off of the electrical schematic you sent.

Cat had one of the fuses labeled 'backup', but that's the backup prv switch, I think I was misled by the wording on the fuse panel.

So, that fuse leads in the schematic over to the hydraulic lock solenoid. Soon as I find it in the relay panel, hope to know a little more.

Btw, I was told to look at that relay earlier by, was it, John... ;D

 

[Nige]

Working on your specific machine Serial Number I have found another document regarding SysOp and Test & Adjust though - RENR1998. It's in a bunch of separate sections so it's not a simple download, but I'll see if I can't download all the separate documents and splice them together with Adobe Acrobat. Stand by ..........

 

[BrianGrenier]

Thanks Nige!

I'm liking what the Waratahs folks have for troubleshooting information. It turns out that the Cat schematic regarding pumps isn't what's on this machine.

Here is how the carrier pilot solenoid valves work (carrier is Cat® 320 BL)

• Electricity sent to the solenoid, causes an electromagnet
• This magnetism shifts the hydraulic valve
• When the valve shifts, this sends pilot pressure to shift the carrier spool and stroke pumps
• High pressure is sent to the Head
• There are two solenoids, pump 1 and pump 2
• Pump 1 shifts the carrier spool to get one pump flow 45 GPM
• Pump 2 shifts a carrier spool to send secondary pump flow to head additional 40 GPM

The Waratah controls the pumps.

 

[Nige]

I'm sorry I have bad news for you regarding RENR1998. It appears to be more slanted towards diagnosing the electronic controls and how they interact with the engine than the hydraulic side of things, certainly when it comes to Testing & Adjusting. Here is the SysOp part of it FWIW.

 

[BrianGrenier]

I'm sorry I have bad news for you regarding RENR1998. It appears to be more slanted towards diagnosing the electronic controls and how they interact with the engine than the hydraulic side of things, certainly when it comes to Testing & Adjusting. Here is the SysOp part of it FWIW.

The sysop was Very useful! Especially so was the block diagram on page 2.

The problem is either with the cabin module for the Harvester head or the controller in the cab.

It looks like a bad Cat controller. As was pointed out earlier. it's never the ECM but this time I think so.

I'm not sure I wrote it earlier but there is no voltage to the prv and I need to finish verifying voltage to the 111-1491 relay from the harvester head controller.

I imagine I will be pricing a Cat controller soon.

 

[BrianGrenier]

I wrote that above for my easy-chair not sure why I jumped to a conclusion as I needed to check the relay further.

I only see .240 ohms resistance at that relay so I need to check specs. There may be other identical relays on this machine.

 

[BrianGrenier]

They say don't weld on the machine with the controller connected. I think the starter commutator frying damaged the controller.

Tracing and checking wiring from both directions to the Cat Controller leads to an electrical fault there. All wires, switches, connections and relays either side of it checked out.

I need a new controller, or a by-pass...

I have a partial copy of senr9291, from the dealer.

Bear with me here in a minute as I try to figure out how to get proper voltage / amperage to the proportional reducing solenoid valve
(PRV).

"a decrease in engine speed increases the signal current to solenoid which increases the magnetic force... The powershift pressure increases and the pump detrokes".

Then conversely, they say
"an increase in engine speed decreases the signal current to selenoid which decreases the magnetic force... The powershift pressure decreases and the pump upsrokes.

What's the correct voltage and amperage to the PRV from the ECM for an 'upstroke'?

24 volts at battery amperage is too much for the prv and it will not upstroke, i tried it.

Maybe I could go to the dealer and they would let me put my clamp meter on a solenoid on a similar machine?

The dealer couldn't tell me what voltage and amperage should be.

 

[TVA]

Brian, two words - “stand-by pressure”! Do you have it?
With your way of thinking you about to turn $8000-$9000 problem in to $15000 problem and making the fool of your self!

Check if you have flow from main pumps!

Before calling it bad controller go through proper procedure of checking it.
Regardless of what I think of you I don’t want you to waste money!

 

[Cmark]

When you activate the backup mode switch, it sends 24V to the PRV through a 47ohm resistor for a sort of "limp home" feature. So 24V / 47R is roughly 0.5A.