Ram creep on front shovel JCB 3cx--solved

[killasan]

Good day fellow machinery-heads! Im stuck on a issue that I jsut cant seem to get fixed.
machine 2001 JCB 3cx. I have recently bought this and the condition was absolutely horrible so I am basically workingm y way trying to repair everything piece by piece.
I am having this problem where the front shovel keeps tipping over (as if offloading). Within a minute from digging position it will tilt to offload position. This is extemely difficult when driving especially and carryin loads. The other rams work wll with no issues. I can lift the shovel arm and it can remain up for days.
Things I have done:
1- Changed all hydraulic fluid and strainer
2- hydraulic filter
3- changed ram seals twice! on both rams
4- new hoses
5-Changed spool seals
6-Replaced ARV orings top and bottom

I am pulling my hair out at the moment as I do not know what else can be the cause. Any suggestions before I weld the ram shut? (jk)

Also I have noticed that the machine will tend to sputter and cut off if the ram levers are held open full and th ram has extended fully. I have read that this is the master relief valve .How does one set this properly?


Thank you for all assitance provided

[philwheelton]

If you crowd the shovel over to lift the front wheels off the ground does it tip back on it's own?

[Stormin]

You could try swapping the hydraulic lines over at the spool block so the bucket spool is swapped with the loader arm one, then see if the loader arm drops. This would help eliminate the spool block as the faulty item.

[Mrsmackpaul]

Stormin Norman is on to it there really isnt anything else it could be

[killasan]

I will be swapping hoses today as i needed to get some longer ones (both sides).

Quick question. If i disconnect a shovel ram and try to use one independently is it supposed to tip still or will it hold pressure under the weight of the bucket? Disconnect meaning removing it from hydraulic flow and closing that circuit on one side while leaving the ram hoses open.

Thanks for the advice so far.

[killasan]

Update:
Swapped the hoses for the loader with the shovel- Shovel still tipped while loader still held pressure. This ruled out and problems with bank/hoses/arv/mrv spools etc. Definitely was the shovel rams. Turns out that both rams are connected and any drop in pressure in either one will result in both losingpressure. The ram was opened revealing the new seals busted again! 2nd set or seals. A new set was installed and same problem occured. ram reopened and revealed that the new seal was jsut busted!!! upon close inspection of the barrel there was a tiny ridge about 2" from the threading. When under pressure it would seem that the seals were being sliced up. Ridge was sanded and fine sanded and polished. 5th set of seals installed and problem solved. Shovels hold pressure and shows no sign of dropping!!!!!!! yay feel good but all those murdered seals ,atleast problem solved.
Thanks again guys!!

[Mrsmackpaul]

Thats what we like to hear another happy customer

Paul