Cat 335fl Rkb10639 When using the controls it seems like the hydraulics have a delayed response. It is the same when letting go of the joystick. The machine takes about 1 or 2 seconds to stop functioning. it makes it very difficult for delicate work. For example if I pull the control back to raise the boom it will linger for a second then start to raise. If I let off the boom may go up a few more inches. Any suggestions as to what may be the cause?
Air in your Servo system most likely
Do you have a repair or inspection procedure available?
Any suggestions? This is driving me crazy
Good day That suggests the RCV (Control lever) is taking its time to drain> possible cause blocked case drain filter or to heavy grade of hydraulic fluid. Kind regards Uffex
I thought these controls were electric over hydraulic? I'm would assume there is still a pilot system but it is controlled by solenoids not the joysticks directly?
Good day I have not checked if you have a hydraulic schematic, that will reveal which you have. You are correct if it has electric over hydraulic the same situation would apply KR Uffex
Good day In the spec. I have fails to mention other than "Electronic control of the main block" maybe Nige has the information. KR Uffex
Its pilot operated With a patern changer
I think that machine does have a pattern changer. But the controls are electric over hydraulic. So no pilot lines in the cab.
Its pilot operated for boom and stick Aux circuit its electric
I will have to get a look at the machine later this week. But I thought all the controls on the f series were electric pilot?
I'm not sure on your machine but in some there is an inline filter on the return circuit of the pilot system. I would start there if you have it. Slow nuetraling response is usually a restricted return circuit in the pilot hydraulics
F series are pilot Nex Gen are electric
Is anyone able to supply a hydraulic diagram so we can check for the filter?
This is the setup of the pilot lines for the 4 main functions (not Aux) plus travel in the cab for your Serial Number. They go straight to the joysticks/foot pedals with no electrics in between.
Attached procedure for changing the implement pilot filter. Element P/N is 5I-8670. The pilot system on this machine has an accumulator. Has anyone checked that it is functioning correctly.? It is quite simple to do, see Steps 1 thru 5 of the "Preliminary test Procedure on Pages 2/3.
Unless this is something different, the accumulator is used to lower the boom or stick if the engine is dead. It shouldn't have anything to do with the delay. It used to be one of my inspection checks but I found so many flat ones that I quit checking them.
recently made it back out to this machine for some other repairs but need to circle back to this... If it still runs it can't be that bad... Tried the accumulator test while on site. Didn't have any gauges but the boom does not come down with the machine off. Tried it on another one at the shop and that machine also did not work. While working on this I was in the service menu and noticed the pilot pressure surging. 300-600 psi. kind of rhythmically. It is visually noticeable in the aux lines at the boom to stick. The lines pulsate slowly. Is there a valve or something in the pilot system I can check with relative ease next time I am at the machine? Often I am very limited on tools while on site. We try to get the machines to the shop once per year for major work but it seems the last few months it is just keep everything moving with no down time between jobs.
Good day Important when you test the accumulator that the start key is in the on position and the control lock out remains in the owrking position. Kind regards Uffex