d6t steering noise fault

Hello
I have a fault with a new seconds d6t, Its making a screaming noise once the steering is asked. The steering performs correctly during operation. I have done a few sis pages on fault finding the steering system. Pressure test results are ok eg charge pressure, stall pressures, steering pilot left and right. no leaking hoses. oil levels ok. oils have been at operation temps, filters changed. If i was to say where the noise is coming from I would say the charge pump end? I have uploaded a video to you tube for the sound for reference. Now I'm stumped as what to do next, worst case is to do an exchange for 5k for the whole pump setup. wondering if someone else has encountered this same issue? any advice?
Thanks in advance
Luke

Serial number lae00404
7000hrs

You say that you changed the filters. Did you happen to cut open the old ones and check for the presence of metal particles down in the bottom of the pleats..?

Did the symptom start suddenly or has it been slowly getting worse over time..?

hi yes old filters were ok. hours on the old filters unknown. just purchased so no history. Ive only done couple hours testing

So if I understand you correctly the machine has been making this noise since you bought it..?
Your reply isn't totally clear. Did you actually cut the old filters open to inspect them..?

yes
and yes

A question;
How do you judge it to be noisy?
Are you comparing it to a similar machine or a gut feeling? It's pretty hard to tell from your video bearing in mind that the floor plates are removed.

If, as you say, all the pressures check out OK and there's no debris in the filters, I would suggest;

1. Take a hydraulic oil sample for analysis. (And transmission, engine and final drives while you're at it, why not? (Ritchie bros machine, right?))
2. Change the hydraulic oil.
3. Run for ~50 hrs.
4. Resample.

I judge my gut it to be noisy because it would drive me mad to listen to it all day long, it is loud, even with the floor plates on. I do have a d6r 2 and its 90% quieter compared to it. but the 6t is a different pump setup to the d6r.
ok sounds like a plan thanks I appreciate it.
Ill sample, change oil. good run, check filter and re-sample.
yeah auction machine, euro auctions, so far its good, just this steering bug.

From the video it sounds noisy even without steering but much worse under load. Is your hydraulic tank building up pressure like it should ?
Does it get better or worse when it’s warm?

Do you have any loss of power? It is loud, but that doesn't mean that there is anything wrong with the machine, in my opinion. What hydraulic oil is in the machine now? If the machine came from a cold weather climate, the oil may be to light for Australia and the source of the noise.

Mobiltech said:

From the video it sounds noisy even without steering but much worse under load. Is your hydraulic tank building up pressure like it should ?

Click to expand...

Is the tank cap holding pressure..? It should seal tight. As a follow-up from that question I'd suggest that you replace the breaker relief valve on top of the hydraulic tank either way. IIRC it's included in the 2000hr PM list at least on bigger tractors anyway, not sure about D6T. Part Number is 191-5439.
If you're going to change the oil I'd suggest to put SAE10W TO-4 in it. If the machine has 7k hours on it now who knows how many hours are on the hydraulic oil.

Pull a oil sample

As an additional point from CMark's suggestion about oil sampling, make sure that the sample analysis from everything apart from the engine includes the ISO Cleanliness Code. that will tell you a lot about the condition of the hydraulic & power train systems.