615C S# 9XG01981 The machine just quit steering according to the operator. I have checked the mechanical link between the steer column and the control valve, its intact so it seems to be some kind of hydraulic issue. I installed a pressure gauge at the test post of the control valve, it reads about 250 psi at start up and never changes whether the engine is at high idle, or operating the steering wheel against the stops. I don't have any evidence of any cylinder issues that I can determine. I have no hydraulic schematic, but I do have an exploded parts view of the pump, control valve, and plumbing lines. Is there any hydraulic problem that may be normal for these machines having to do with the steering? How should I go about eliminating the pump, or the control valve as the problem? I removed the outer part of the relief valve and could see no issue there. Any help would be appreciated!
Maybe one or the other of these will give some ideas: View attachment 615C Schematic SENR5698.pdf View attachment 615C steer sys. op..pdf
hi I have come across this before. in kens 615c steer system operation valve #9 has a small hole that blocks up .This valve is the unloader valve and dump system pressure to tank
I wanted to thank both you guys for the info. I will be back on this machine this morning. After looking at the schematic kshansen provided, I agree I could have a problem with the #9 valve. I will check it first! I will update this evening, repaired or not.
Well, I found part of the issue but not the main problem. I pulled the relief and dump valve out of the steering control valve and found a small conical spring stick in a side port hole of the dump valve, which was causing it to stick. After reassembly, I have better pressure but not enough to steer the machine. This small spring may be from a check or shuttle valve in the schematic, but not sure. Its a small spring and doesn't take much to compress. 1/2 inch long, 3/8 inch or so on one end, and maybe 1/8 inch on the other end. I contacted my local Cat dealer here, and they are sending me a breakdown of the 2T2402 shuttle, but have no breakdown of the 9T2553. I'll be trying to determine where this small spring came from, which is probably the main failure and the original cause of this issue............to be continued.
Not sure if this will help but here is a little information on the 9T2553 View attachment 9T2553.pdf Does not appear to have separate parts available but it might give you a hint at what should be inside. Any chance of posting a picture of this part you found? Maybe next to a penny or something to give an idea of it's relative size? Does this 615C have the "secondary steering system" I believe that is what Cat calls the system that has a pump powered by the drive wheels in a way that even with a dead engine while rolling along you still have some steering.?
Yes, it does have the secondary steering system. The secondary pump is a piston/pressure compensated pump on the back of the transmission. I do not know how to post pictures yet, but Maine a small spiraled spring in the shape of an ice cream cone.
I swear I hate auto correct. LOL I can't see enough of the spring to be able to tell much. Since it was found in the dump valve from the pump inlet side, I'm figuring it had to come from somewhere between either the main steering pump, the secondary pump, and the control valve pump inlet. All I'm really seeing is these check valves and a shuttle valve, but this spring seems to be too small for those items, in my opinion of course.
Im going to run a pump flow test in the morning on the main pump. I have a flow meter to hook up to it so I can at least eliminate a flow or pressure issue from it. I will post those results tomorrow afternoon.