Jcb 8018

[Kingroger]

Hi everyone.
I have a problem with the Hydraulics of my JCB 8018. The left hand joy stick is slow to respond unless I hold the right hand joy stick just touching the slew button but not enough for it to slew, or hold the blade lever against the button but not enough to move it. The hotter it gets the worse it gets. Has anyone got any ideas. Cheers.

[Muz]

Are the pilots moving up and down ok, (look under the rubber collar)

[v8druid]

queer one that ..... still thinking

[Kingroger]

Jcb 8018

MUZ. The pilots are moving as they should.
Had fitter out he found nothing pumping at correct pressure. His only suggestion was that maybe there was a partial blockage in the main valve block.I removed some of the pipes to the left of the block including the main feed from pump, found no debris etc. I noticed a pressure Valve on the main feed into the valve block. (Just a sprung loaded ball) It was clear of debris but wondered if this might be the problem. Once the left lever was held against the slew button the demand for more oil pressure was such that it opened and let more oil through. Any thoughts on that theory. Cheers.

[pets56]

Hello. I have similar problem with my jcb 8018 . If its cold it will work well but when its getting warmer then left hand joystick up and down movement going really slow. Left and right functions (turning cap) are okey. Then right hand joystick going also all functions going slow but when its slow and you moving left hand joystick ( dosent matter witch way) then its going fast again. So when its warm movning going slow and if you touch left hand joystick then its going fast again. Hydraulic oil and filter are changed. low pressure pump is also okay. (Pressure is okay)

[Muz]

If its a variable displacement pump, some are fitted with an 'unload valve' that returns the swash plate to a low or nil delivery setting when the machine gets shut down so as not to load the engine at start up, might be worth checking that that , or some other valve like the Aux service isnt stuck making it do silly things ?

[v8druid]

If its a variable displacement pump, some are fitted with an 'unload valve' that returns the swash plate to a low or nil delivery setting when the machine gets shut down so as not to load the engine at start up, might be worth checking that that , or some other valve like the Aux service isnt stuck making it do silly things ?

If it's a VDP Muz, I'd be looking at the load sensing circuit ..... and checking pressures in that .... if the LS line to the pump, from the valve block, is blocked (and it's a tiny orifice to flow through - 0.6mm on mine), then the pump won't upstroke and produces zero pressure, which is default , so that, as you say, the pump doesn't load the motor on start up and saves fuel, off demand, only making the required pressure as needed.

LS line problems create all sorts of weird presentations and blockages take some finding