Jcb TM300 steering issue

[Romeogolf]

Good morning,

I have a Jcb TM300 which is showing some interesting symptoms.

Some time ago, my dealer replaced the accumulator responsible for releasing the pressure on the third service at the headstock as this had failed. Ever since that day, the orbital in the steering column has been ‘clucking’ when the steering wheel is not moving. Turn the wheel and the noise disappears, leave it alone and it clucks like a hen. Further to this, the noise is much more noticeable when the machine is warm, but also starts to whine from the pump at the rear of the machine, but this time only when you turn the wheel. The whine stops when you release the wheel, and the clucking returns.
The dealer is adamant there is no connection between the third service accumulator and the steering, but I do not believe this is a coincidence. Aside from having a irrational dislike of annoying noises, I am worried something isn’t right and I am wearing things out prematurely as a result.
I would be very grateful for any responses that may be able to shed some light on the situation.
Thanks

 

[ACEngineering]

Good morning,

I have a Jcb TM300 which is showing some interesting symptoms.

Some time ago, my dealer replaced the accumulator responsible for releasing the pressure on the third service at the headstock as this had failed. Ever since that day, the orbital in the steering column has been ‘clucking’ when the steering wheel is not moving. Turn the wheel and the noise disappears, leave it alone and it clucks like a hen. Further to this, the noise is much more noticeable when the machine is warm, but also starts to whine from the pump at the rear of the machine, but this time only when you turn the wheel. The whine stops when you release the wheel, and the clucking returns.
The dealer is adamant there is no connection between the third service accumulator and the steering, but I do not believe this is a coincidence. Aside from having a irrational dislike of annoying noises, I am worried something isn’t right and I am wearing things out prematurely as a result.
I would be very grateful for any responses that may be able to shed some light on the situation.
Thanks

Dealers right there is no direct link from steering to the 3rd service.

TM300 have the same crappy steering priority valve that Matbro's used for years.
(edited should add same type/make not necessarily exactly the same pressure and flow settings/ratings!)

valve gives priority flow to brake circuit and steering over main hydraulics.

It sound to me like you might have a worn hyd pump, possibly even sucking air? which is then going through the steering, or its trying to charge the brake circuit accumulator a lot because accumulator has failed or because lack of pump pressure or faulty brake charge valve in the main priority valve block.

The only other thing that springs to mind is i doubt there is a accumulator just for the 3rd service! i would expect it to be for all the joystick services?

Now what IF some random fitter was sent to fit joystick pilot accumulator but actually mistook the brake accumulator for the pilot accumulator and it actually happened to screw on the same fittings Just a random idea

 

[Romeogolf]

Now what IF some random fitter was sent to fit joystick pilot accumulator but actually mistook the brake accumulator for the pilot accumulator and it actually happened to screw on the same fittings Just a random idea

Thanks for your reply, what would be the outcome if this had happened? The brake and pilot accumulator are next to each other, but since the birth of the problem they have been out and changed the brake one too.

I just cannot ignore the fact that the moment the dealer left the yard, this problem started. There may be no direct link, but isn’t there a way in which the pumps overflow into each other? The machine has a pump for the steering, and a pump for the main hydraulics.I was led to believe that when the steering wasn’t being used the power from that pump fed back into the main hydraulic circuit.

 

[ACEngineering]

Thanks for your reply, what would be the outcome if this had happened? The brake and pilot accumulator are next to each other, but since the birth of the problem they have been out and changed the brake one too.

I just cannot ignore the fact that the moment the dealer left the yard, this problem started. There may be no direct link, but isn’t there a way in which the pumps overflow into each other? The machine has a pump for the steering, and a pump for the main hydraulics.I was led to believe that when the steering wasn’t being used the power from that pump fed back into the main hydraulic circuit.

Theirs 2 pumps both Tee in to each other, feeding a steering priority valve almost identical to the old matbros, priority valve splits the flow between steering, charging the brake circuit and pilot circuit and whats left goes to the main hydraulics.

There is no dedicated steering pump, or at least there wasn't on the 2 i used to look after on a 2005 plate.

 

[Jato]

Has the new accumulator charge been confirmed as at one time JCB would not ship pre-charged units.
They had to be charged at dealers.

It does sound plausible that the system is frequently charging the steering and brake circuit.

is the third service pressure release concern fixed now?

 

[Romeogolf]

The new accumulator was installed by the dealer, brought pre charged by the fitter as you correctly say they wouldn’t send it pre charged. It’s solved the third service pressure release, yes, which has made the change of implements much more pleasant, however the irritation from the resulting problem is equally as frustrating as releasing oil pressure with the spanner’s!
What could make the orbital cluck? Is there a priority or change over valve in there that could be constantly flickering as a result of increased/decreased pressure?

 

[Nav man]

The new accumulator was installed by the dealer, brought pre charged by the fitter as you correctly say they wouldn’t send it pre charged. It’s solved the third service pressure release, yes, which has made the change of implements much more pleasant, however the irritation from the resulting problem is equally as frustrating as releasing oil pressure with the spanner’s!
What could make the orbital cluck? Is there a priority or change over valve in there that could be constantly flickering as a result of increased/decreased pressure?

did you ever sort this. changed nearly all accumulators but still clucking once worm.

 

[Romeogolf]

did you ever sort this. changed nearly all accumulators but still clucking once worm.

No, machine is still the same.

It’s done it for long enough for me to zone it out and it doesn’t seem to alter the machines performance.
Now you’ve reminded me of it I would still love to resolve it!