No front lift.

[Mikerb]

My 3CX can not lift the front bucket unless the engine is nearly full throttle.

Is this the ram(s) letting by, or could it be something else?

Everything else seems to work as well as it did.

[Mrsmackpaul]

I reckon you will have a crook seal in a ram if every thing esle works ok

Paul

[Mikerb]

I capped off the hoses on each side one at a time, and they both lifted the bucket (only while revving the engine). I have now taken both rams out and the seals look good, no splits or chunks taken out, one of them has been changed in the past and looks fairly new. So I'm not quite sure the rams aren't letting by. I will change the seals while they're out anyway.

What else could be causing this?

[Mrsmackpaul]

Is there a relief valve in your spool valve (the hand control valve) for the loader if so maybe something is stuck under it or the needle part of it is badly worn
Does the rest of your loader work fine I assume you have a backhoe on it, if so does the backhoe still work fine

do you have access to a preasure gauge I had a whole heap of dram with my loader recently ( not a JCB ) and until then I could only guess were the problems were once I borrowed a gauge the problem was narrowed down to what it was in a matter of a hour or so ( wasnt good news for my hip pocket ) but the problem was fixed


Paul

[FOWLER MAN]

Hi Mike,
The problem with your loader lift if every other service is performing correctly is probably a faulty ARV ( Auxiliary relief Valve).
These live behind a plug in the under side of the spool block, one under each slice of the block.
The pilot valves are bullet like in shape and can be easily removed. Don't strip these pilot valves they have to be reset off the machine and you can't repair them anyway so don't try. I used to replace them or get them reset by JCB.
The seat of the ARV is in the plug which holds the valve in the block and the point of the bullet seats against it. The valve and seat should be replaced as a pair if required.
Could just be an O ring or bit of seal or dirt in there if your lucky. Be sure to use new O rings when you reassemble it.
Some 3C's have a different make of valve but the principal is the same.
Fred


Oops, Just noticed you have a 3CX.
The info I have given refers to the 3C. I'm not so familiar with the 3CX, but I do know there are ARVs for the bucket ram circuit but they adopted a different system of unloader valves to protect the lift circuit.
I still think your problem will be one of these valves in the spool block.
Sorry for the confusion.
Fred

[Mikerb]

Thank's for the replys!

Yes everything else works as it should. I will check out this valve over the weekend.

[Mikerb]

I emailed Vicary Plant explaining and asking for a price, this is the reply; "There are no ARVs on the lift circuit you need to put a pressure gauge on and check pressures as front and rear are set independently, you need to see about 3000psi"


There is only a problem with lifting. I can lift the digger up by moving the bucket down. When I try and lift the bucket with engine at idle, there is a hissing from the control block, suggesting that the oil is letting by. Could the spool be worn and letting oil by?

[essexpete]

How are the spools controlled on that model? Is the lever in the cab actually moving the spool the whole way?

[Mrsmackpaul]

If the spool valve is remote mounted maybe something has come loose and the spool is either traveling to far or maybe not fare enough

I would recommend borrowing a pressure gauge from someone to give some feed back can save a lot of time and guess work

Paul

[Mikerb]

I put a pressure gauge on it today and when lifting got 200psi when idle but then 2000psi when revved up. I then tested the lowering and got 2500ish psi when idle. So it's just the lifting stage with a problem.

The spool is attached directly to the control arm witch moves it up and down as you move the lever forwards and back. There is no slack in the system so the lever is moving the spool to its full travel.