JCB 3C Mk3 - hydraulic system bleed

[rocky_robin]

The manual is not clear on this, but have you to bleed the hydraulic system once you have re-installed a ram?
I've just removed the stabliser ram (due to a red-rotted metal hose repair) and I've re-installed it.
It will stroke open, but does not want to close. It will vent and release the stroke pressure, but will not stroke closed. I've got flow to both lines, but nothing. They both worked before I repaired the pipe. I can stroke the ram shut using a ratchet strap, but it just collapses down to the ground once I remove the strap.

I lost a lot of hydraulic fluid during the repair so I'm thinking that I've got air trapped somewhere.
All other rams on the machine work no problem. Just this one stabliser! Grrrrrr!!!

Any ideas?

One more thing, I've read that you can bleed air from the slew, but I can't see any bleed point for this. Any assistance?

[philwheelton]

You should just work the ram both ways and it will push any air out sound like you have another problem with the ram,have you had a new pipe welded on if so have the seals been warm! and yes you have to bleed the slew only one way.
Phil.

[rocky_robin]

It was rotten about 12in higher than the inlet, so I just patched the hose itself, so heat was not seen at the cylinder.
I did think that it may be the ram, but I couldn't think of anything other than trapped air (like bleeding brakes on a car).

[essexpete]

With luck it will be a piston seal but the I wonder if the piston head has come adrift?

[rocky_robin]

My way of thinking was that if the ram can hold pressure in one direction (fully stroked out), it should hold in the other direction too or am I talking out my rear end? (more likely!!)

[essexpete]

I have had a piston break off the rod and the piston will push out the rod but on return spool the piston works back without the rod. (if that makes sense).

[rocky_robin]

Ahh. I understand fully now. I hope to heck that I don't have that issue! Will have a look...........

[rocky_robin]

Well, what a ploker I feel like!
Thanks Pete for pointing me in the right direction.
Basically, when I was lining up the foot to the piston hole and box section, I thought the piston was in position. Instead it was turned 90deg and was not fully lined up. In the end, the piston was sitting on top of the pin, so it would stroke out no bother, but would stroke back in itself without the foot and box section.

[Bog Man]

:arrrrgh: Well, what a ploker I feel like!
Thanks Pete for pointing me in the right direction.
Basically, when I was lining up the foot to the piston hole and box section, I thought the piston was in position. Instead it was turned 90deg and was not fully lined up. In the end, the piston was sitting on top of the pin, so it would stroke out no bother, but would stroke back in itself without the foot and box section.

It might be an idea to have a note in your pocket with your name and address and a contact number of your carer .

[rocky_robin]

They are already written on my labels on all my clothes.