My big 14M steering system problem

[Pep Joe]

I will be happiest if I get a client 14M motor grader steering working again. Will be in big mess if it don't work because I told them the problem is the primary steering control valve module. They Believed me and spent big money to get a new one and after installing it same problem.
Below is the codes gotten with CAT ET and warning lights showing on the monitor.
Thanks

 

[Nige]

Serial Number.? EDIT: Found it on your photo - R9J00207.

Questions:
1. When you took that 1st photo was the steering set hard over to the right.?
2. Has it had any steering cylinders repaired or replaced recently.?
3. What software Part Numbers does it have installed in the Implement #1 & #2/Transmission/Engine ECMs.? Four ECMs in total.
4. Do you have the capability to upload new/updated software flash files.?

 

[Pep Joe]

Serial Number.? EDIT: Found it on your photo - R9J00207.

Questions:
1. When you took that 1st photo was the steering set hard over to the right.?
2. Has it had any steering cylinders repaired or replaced recently.?
3. What software Part Numbers does it have installed in the Implement #1 & #2/Transmission/Engine ECMs.? Four ECMs in total.
4. Do you have the capability to upload new/updated software flash files.?

Thanks for your reply sir.
Answers to your questions.
1.when I took the first picture, yes it will steer hard right sometimes and not steer back. Sometimes times it steer left fine and and stop always at right full steer.
2. I have not asked so I don't even know for now. Maybe will ask and get back to you .
3. I upgraded all the ECMs except the product link ecm
With the above flash files
4. Yes I have the capability to upload new software files. I have cat diagnostic tools.

I have carried out 2202-12 code troubleshooting and all wires to the primary steering control valve module from implement ecm #1 are good, no short and no open circuit and the primary steering control valve pull up resistor resistance is ok. I got 503 Ohms.
I seem not to understand what the problem is now. I'm only good at the electrical side I'm not a mechanical guy.
Yes that is the correct serial number: R9J00207
Thanks.

 

[Pep Joe]

Thanks for your reply sir.
Answers to your questions.
1. When I took the first picture, yes it will steer right hard anytime the steering system responds. It steer left smooth anytime the steering system responds and not steer back at right full steer.
2. I have not asked so I don't even know for now. Maybe will ask and get back to you .
3. I upgraded all the ECMs except the product link ecm View attachment 254583
With the above flash files
4. Yes I have the capability to upload new software files. I have cat diagnostic tools.

I have carried out 2202-12 code troubleshooting and all wires to the primary steering control valve module from implement ecm #1 are good, no short and no open circuit and the primary steering control valve pull up resistor resistance is ok. I got 503 Ohms. It logged this 2202-12 anytime the steering won't work
I seem not to understand what the problem is now. I'm only good at the electrical side I'm not a mechanical guy.
Yes that is the correct serial number: R9J00207
Thanks.

 

[BigWrench55]

Is this a sudden failure or a gradual failure?
Any story to go along with the problem?
What did the operator tell you?
It sounds like to me that one of the steer cylinders packing is blown.

 

[Nige]

I need to go digging a bit but I have some more questions meantime.

1. What Part Number of steering control valve did you install.? Was the valve brand-new.?
2. Has anyone tried disconnecting the steering cylinders, jack up the front axle until the wheels are off the ground, and try moving the wheels manually to check for something mechanical binding in the front axle.? While they are doing that check for excessive play in all the front axle/wheel pivot points.

You need to ask some more questions to the operator/customer........
Does the problem only occur when the steering is at maximum turn angle and when the joystick is moved in the other direction the steering fails to move back towards the centre in response to the joystick.? If the answer confirms that the steering "fails to respond" only when it is at maximum turn angle then I would strongly suspect something mechanical in the front axle as the root cause.
Is the problem worse when turning left, when turning right, or about the same both ways.?

Regarding Point #2 above. The particular areas to inspect are circled in the illustration below but I would suggest to inspect every ball joint, tie rod, & pivot while you are in there. Also keep a close eye on the axle as the machine is being jacked up and see if you can see any play anywhere.

 

[Pep Joe]

Is this a sudden failure or a gradual failure?
Any story to go along with the problem?
What did the operator tell you?
It sounds like to me that one of the steer cylinders packing is blown.

Thanks for your reply sir.
It's a gradual failure because the steering system still work now sometimes and sometimes Struggling to steer right.
Anytime it fails it's when it's fully steer right and the warning lights for primary and secondary steering will come up and steering will fail.
The messenger will display a steering system malfunction.
I haven't go check the steering cylinder yet but I will now that you made mention of it.
No plenty story the operator said the failing has been there for long and was using the machine like that but becoming too failing often now so they brought it to a stop and ordered for the problem be fixed.
I'm on the machine now.

 

[Pep Joe]

I need to go digging a bit but I have some more questions meantime.

1. What Part Number of steering control valve did you install.? Was the valve brand-new.?
2. Has anyone tried disconnecting the steering cylinders, jack up the front axle until the wheels are off the ground, and try moving the wheels manually to check for something mechanical binding in the front axle.? While they are doing that check for excessive play in all the front axle/wheel pivot points.

You need to ask some more questions to the operator/customer........
Does the problem only occur when the steering is at maximum turn angle and when the joystick is moved in the other direction the steering fails to move back towards the centre in response to the joystick.? If the answer confirms that the steering "fails to respond" only when it is at maximum turn angle then I would strongly suspect something mechanical in the front axle as the root cause.
Is the problem worse when turning left, when turning right, or about the same both ways.?

Regarding Point #2 above. The particular areas to inspect are circled in the illustration below but I would suggest to inspect every ball joint, tie rod, & pivot while you are in there. Also keep a close eye on the axle as the machine is being jacked up and see if you can see any play anywhere.

View attachment 254592

Thanks for reply sir.
Answers to your questions.
1. The part number is 3080934
2. No one has disconnected the steering cylinder since I started my work on the machine. We will try that now but what do you mean by mechanical binding and excessive play in th front axle/wheel pivot joints?

Yes the problem only occurs when it's maximum at steering right cylinder position 100% from the Et status.
The problem has not happen when it's on left steer full angle or half way.
Left steer is smooth and no problem anytime it steer left.
Anytime it steer left it return smoothly.
The steering is at maximum right steer now and not returning.
The I'm suspecting something wrong with the steering right cylinder but I don't know exact what it could be.

 

[Nige]

Steering control valve you installed is the latest Part Number. Was it new or used.?

We will try that now but what do you mean by mechanical binding and excessive play in the front axle/wheel pivot joints?

What I mean is that if you have wear in either of those joints that I circled in the illustration above on both the left and the right side of the machine there could be a possibility that the steering is becoming jammed mechanically when the wheels are at full right turn angle because of wear in the pivots. Watch those pivots very carefully for any movement (there should be zero if everything is in good order) when you jack up the front of the machine. If anything moves in the slightest when you jack up the machine then the pivots will most likely require disassembly and evaluation then rebuild with new parts before proceeding.

The other possibility is internal within the steering cylinders. Do not assume that the right cylinder could be the problem just because the steering jams when steered to the right. It could just as easily be the LH cylinder with a problem. The reason I asked if either cylinder had been rebuilt is that there is a position sensor inside it that requires re-calibration if the cylinder has been disassembled for any reason. That is the same sensor that gives you the 0-100% “cylinder extension” reading on ET

I will speculate right now that the machine does not have an automatic grease system. I don’t think that I have ever seen an M-series front axle adequately greased unless the machine had autolube fitted, and even then it was a lottery. Lack of grease causes accelerated wear in the pivots.

No plenty story the operator said the failing has been there for long and was using the machine like that....

Did the operator happen to mention what he had to do in order to “un-seize” the steering when the problem first started to occur.?

 

[Nige]

Another suggestion.
Don't forget to put the lock pin (or a large nut & bolt) in the front axle before you lift it up. That way both front wheels will lift off the ground at the same time and also the front wheel lean cylinder will not be able to move.

See the attachment for information regarding the steering cylinder sensors.
Ask the customer did this problem start maybe just after a steering cylinder was replaced or repaired.?

 

[crane operator]

Being the expert mechanic that I am, I'm just going to throw out a wild idea. Could you just take the hoses off of the steering cylinders and swap ends? If the problem is control- it should throw it all to the left, and if its a cylinder issue, things should still be messed up in the front end and staying to the right. I. E. on the steering cylinders swap rod for piston sides by switching the hoses and see what it does.

Nige is the expert here on anything CAT, but it would at least narrow it down from if you have a issue up front, vs problems with the electrical control. Of course I could be full of nonsense and nothing would work right on the machine because there's a bunch of sensors that won't let it do that.

I guess you could also put in some pressure gauges on the front between hose and cylinder and see if its putting any pressure out at the hose when the control is telling it to turn. You can also remove non pressure side hose on the "turn left" and see if you have hydraulic bypassing the piston of the cylinder, because of damage in the barrel when its at full right and you are telling it to go left. If there's hydraulic coming out of that return side, and the cylinder isn't moving, there's damage inside.

And just because I'm curious- in the steering diagnostic and set up that you attached nige- if the cylinder fell out of the range allowed for movement right- I. E. the cylinder has gone further to the right than the parameters of the system allows, would that then lock the steering and not allow steering in either direction because there is a fault and its out of the range- and then the system shuts off?

 

[Nige]

And just because I'm curious- in the steering diagnostic and set up that you attached nige- if the cylinder fell out of the range allowed for movement right- I. E. the cylinder has gone further to the right than the parameters of the system allows, would that then lock the steering and not allow steering in either direction because there is a fault and its out of the range- and then the system shuts off?

Exactly why I was asking had any cylinders been repaired or changed recently. If a cylinder is registering a different percentage of movement than it actually has moved physically bad things can happen. I had the dubious pleasure of working with very early M-Series graders and can tell you it was a painful learning process. Software upgrades and service programs were coming almost monthly back then. Steering updates were top of the list IIRC.

Being the expert mechanic that I am, I'm just going to throw out a wild idea. Could you just take the hoses off of the steering cylinders and swap ends? If the problem is control- it should throw it all to the left, and if its a cylinder issue, things should still be messed up in the front end and staying to the right. I. E. on the steering cylinders swap rod for piston sides by switching the hoses and see what it does.

Not a bad idea at all. I think that it ought to be possible to swap the hoses where they come off the front chassis on to the axle underneath that tin cover right behind the push block.

My first though was something mechanical jamming one or other front wheel at full right lock. Pulling two pins disconnects the steering cylinders so it ought to be pretty easy once that is done to jack up the front end and look for play and/or move it left & right to check for anything binding up. As I mentioned above unless the machine is equipped with autolube (and I can't see the grease pump on top of the drawbar in the photo above) I'd pretty much guarantee that all the front axle grease points will be under-lubricated. There are 16 grease points in total on that front axle if I my memory serves me correctly.

 

[Pep Joe]

Steering control valve you installed is the latest Part Number. Was it new or used.?
What I mean is that if you have wear in either of those joints that I circled in the illustration above on both the left and the right side of the machine there could be a possibility that the steering is becoming jammed mechanically when the wheels are at full right turn angle because of wear in the pivots. Watch those pivots very carefully for any movement (there should be zero if everything is in good order) when you jack up the front of the machine. If anything moves in the slightest when you jack up the machine then the pivots will most likely require disassembly and evaluation then rebuild with new parts before proceeding.

The other possibility is internal within the steering cylinders. Do not assume that the right cylinder could be the problem just because the steering jams when steered to the right. It could just as easily be the LH cylinder with a problem. The reason I asked if either cylinder had been rebuilt is that there is a position sensor inside it that requires re-calibration if the cylinder has been disassembled for any reason. That is the same sensor that gives you the 0-100% “cylinder extension” reading on ET

I will speculate right now that the machine does not have an automatic grease system. I don’t think that I have ever seen an M-series front axle adequately greased unless the machine had autolube fitted, and even then it was a lottery. Lack of grease causes accelerated wear in the pivots.
Did the operator happen to mention what he had to do in order to “un-seize” the steering when the problem first started to occur.?

I am sorry now for my late reply, been busy trying to get it working again.
we have not carried out any of mechanical work.
yes no automatic grease system.
according to what they told me not the operator, they said anytime it stop steering they will off the machine and leave it for like three minutes and start it again, sometimes it start working immediately again and sometimes not work.

We have not done any mechanical work yet because power to the primary steering control module is cutting off anytime it won't work. There is a green indicator light that will light when it receives power and it will steer fine and the light goes of when it won't steer. this is something we noticed today.

The primary steering valve module I had thought they bought new is not new, one of their worker told me that today. He said it's not a new one but one loosed from another 14M of same serial number prefix in their workshop that has it's engine overhauled. They lied to me.
When I confront their manager he said it's too expensive to buy when they not 100% sure it's the problem.

Today I carried out 2202-12 diagnostic code troubleshooting again. all wires are good, no open no shorting.
my question now is why is the power to the module shutting of sometimes?
can the other things you mentioned be responsible? if yes we should be going checking all that tomorrow.

steering works fine even to right and left anytime the primary control valve module receives power and the green indicator light on it lit.
Thanks

 

[Pep Joe]

Being the expert mechanic that I am, I'm just going to throw out a wild idea. Could you just take the hoses off of the steering cylinders and swap ends? If the problem is control- it should throw it all to the left, and if its a cylinder issue, things should still be messed up in the front end and staying to the right. I. E. on the steering cylinders swap rod for piston sides by switching the hoses and see what it does.

Nige is the expert here on anything CAT, but it would at least narrow it down from if you have a issue up front, vs problems with the electrical control. Of course I could be full of nonsense and nothing would work right on the machine because there's a bunch of sensors that won't let it do that.

I guess you could also put in some pressure gauges on the front between hose and cylinder and see if its putting any pressure out at the hose when the control is telling it to turn. You can also remove non pressure side hose on the "turn left" and see if you have hydraulic bypassing the piston of the cylinder, because of damage in the barrel when its at full right and you are telling it to go left. If there's hydraulic coming out of that return side, and the cylinder isn't moving, there's damage inside.

And just because I'm curious- in the steering diagnostic and set up that you attached nige- if the cylinder fell out of the range allowed for movement right- I. E. the cylinder has gone further to the right than the parameters of the system allows, would that then lock the steering and not allow steering in either direction because there is a fault and its out of the range- and then the system shuts off?

Thanks for your reply.
I understood all you explained plus I believe they could be the likely causes. one thing is if the primary steering control module is not receiving power, no hydraulic oil will flow to the steering system and so no steering will function.
I discovered today that the steering system only stopped steering when the primary steering control valve module don't receive power from the implement #1 ECM.
I carried out 2202-12 and all wires are ok, no open no shorting. pull up resistor resistance 503 Ohms.

I had thought it's a new primary steering control valve module they fixed but today I found out it's an old one and I don't know the condition before.
I'm still having all active logged event code on my first post. E258 (3), E1374 (3), E1375 (3)

 

[Pep Joe]

Exactly why I was asking had any cylinders been repaired or changed recently. If a cylinder is registering a different percentage of movement than it actually has moved physically bad things can happen. I had the dubious pleasure of working with very early M-Series graders and can tell you it was a painful learning process. Software upgrades and service programs were coming almost monthly back then. Steering updates were top of the list IIRC.
Not a bad idea at all. I think that it ought to be possible to swap the hoses where they come off the front chassis on to the axle underneath that tin cover right behind the push block.

My first though was something mechanical jamming one or other front wheel at full right lock. Pulling two pins disconnects the steering cylinders so it ought to be pretty easy once that is done to jack up the front end and look for play and/or move it left & right to check for anything binding up. As I mentioned above unless the machine is equipped with autolube (and I can't see the grease pump on top of the drawbar in the photo above) I'd pretty much guarantee that all the front axle grease points will be under-lubricated. There are 16 grease points in total on that front axle if I my memory serves me correctly.

no cylinder has been repaired the workshop mechanic guy told me that today but i don't believe this time.

 

[Nige]

I need to apologize. I saw your Steering Valve Part Number and recognized it from my 16M experience.
It is not correct for your particular 14M S/N R9J00207. The correct P/N is 308-0935.

So you need to dig into the original steering valve (the one you removed) a bit deeper, specifically into the electro-hydraulic actuator. Ref #9 circled in the illustration below. What Part Number is it.?
The latest reliable version of that actuator is Part Number 471-7935. Earlier Part Numbers such as 301-5359 & 380-0405 suffered from problems of intermittent operation on machines with high operating hours. We had many failures of both those P/N on early 16M graders built around the same time as your 14M. At one time I recall we had our entire 16M fleet down and every one of them was waiting for a steering valve actuator. None were available anywhere in Cat's Parts system.
My guess is that you will find a 380-0405 installed because the latest P/N was only fitted from machines R9J00931-Up.
If that is the case then you should replace the existing actuator with a NEW 471-7935 actuator. Also replace the seals Ref #2. Seal kit Part Number 301-5657.

 

[Nige]

Sorry should have also included the latest Service documentation from when the 471-7935 was introduced.
The 471-7935 valve actuator was effective ex-factory from machine R9J01368 onwards, so well after your machine was built.

 

[Nige]

There has been another change in that valve actuator. It is now up to "Generation 7". The latest P/N from 2019 is 559-3552 which replaces 471-4935.
All 14M graders with S/N prefix R9J up to the last machine built can use this P/N of actuator.
If you purchase the actuator from the Cat dealer whichever of those Part Numbers you order you should receive the 559-3552.

 

[Pep Joe]

There has been another change in that valve actuator. It is now up to "Generation 7". The latest P/N from 2019 is 559-3552 which replaces 471-4935.
All 14M graders with S/N prefix R9J up to the last machine built can use this P/N of actuator.
If you purchase the actuator from the Cat dealer whichever of those Part Numbers you order you should receive the 559-3552.

Many thanks sir for taking your time to see I get all needed for my client 14M steering problem fixed.
Just as you have mentioned I was thinking the same too, that a new steering valve module should be fixed as we don't know the conditions of the ones we have been working with.

Now that you've have helped with the correct part number (308-0935) I think I should make them buy it and hopefully it fixed the almighty steering problem when installed as the wires are ok and updated flash files installed.

Another thing I need to ask is; can I change the electro-hydraulic actuator alone, the one you circled (471-7935) ?

I will not fail to give update on how it's going with us.
Thanks sir Nige for the information you have been proffering free. I know this will be of great help to many others too.

 

[Nige]

Another thing I need to ask is; can I change the electro-hydraulic actuator alone, the one you circled (471-7935) ?

Based on your location I would suggest that you order the latest 559-3552 Part Number. There is a small chance that your dealer may have an "old" 471-4935 in his parts stock and you do not really want that one - you want the latest "Gen 7" design of actuator.

Yes you can change just the actuator without changing anything else on the steering valve.
Be sure to change the five seals between the actuator and the body of the steering valve. Using the old ones is pretty much a guarantee that it will leak after installation.

Take a look at this thread regarding a steering valve actuator failure on a 140M. Some of the Events/Codes are identical to yours and so was the diagnosis - a defective actuator.
Note also that this guy replaced the resistor in addition to the actuator.
Please note carefully the comments made in Posts #8 & #17 regarding the shuttle valve/resolver which is not part of the actuator but will probably be stuck to it when the old actuator is removed from the steering valve. The resolver should be removed from the old actuator and installed in the new actuator before installtion. Also note the fact that the new 559-3552 actuator comes complete with a set of new seals.

https://www.heavyequipmentforums.com/threads/140m-steering-fault.88621/#post-964785