Hello, I have had little response to my thread so I will post generic question here as I believe my problem is one of these two. A lack of movement to main hydraulic function from 1 direction on joystick pilot control, Would this indicate a sticking plunger spool or a blockage in the ball resolver? How can you test to know which one it is? Both are upstream of main spool so can’t simply take hose off there. Thanks.
What machine?
Hey Cat 287b zsa03475 Multi terrain loader
There isn't enough information to tell you anything. What function isn't working? Is that function not working in either direction? Has there been any recent work done on the machine? Does the machine make any noises out of the ordinary when operating that function? Does the engine sound like it's under a load when that function is used? Has the hydraulic system had the filters changed recently?...and was there any evidence of contamination?
All the I formation was provided under the MTL section. My machine is perfect. I merely changed plunger seals. Everything worked after repairing seals. The next day I unscrewed the ball resolver Allen key seat screws. Put them back. Straight after I lost forward control and left was really slow. I have narrowed it down to what I believe was check valve. I stripped everything apart today undid the resolver screws and noticed ball bearing was missing in one. Hallelujah I thought, I went looked on floor of posi and actually found it. I put it back in, reassembled and and now when I press forward plunger and left machine turns fast left. But now I still have no forward plunger control and now now no left plunger control I’m close , but can figure it out. I need the resolver schematics I think.
so pilot pressure is getting to joystick, Reverse works fine, right turn is fine, But only left turn when both forward and left are pressed with joystick. Individually, I press forward down, no forward movement, No sound , no nothing, same with left now. Clearly a blockage of some kind I’m thinking.
Problem solved
SOOOOOOOOO?
i undid a ball resolver seat, which is one of four Allen key screws at the bottom of resolver. I didn’t realise at the time, but it actually sheared in half as I was undoing it. When I screwed it back, obviously the check valve (ball) was faulty and it closed off the C port which is shared by the forward drive function, and the left turn function. Lesson DO NOT TOUCH the Allen key ball resolver seats. Because they aren’t replaceable and you are up for $700 AUD for a new resolver.