Hi everyone, I am new to the forum and am in need of advice for fixing my 2000 cat 416c backhoe. I noticed I was leaking a decent amount of hydraulic fluid the other day and discovered that the valve body for the front bucket was leaking. Specifically, the valve that controls the front bucket up and down functions. I can see it spray fluid when I remove the floor and operate the bucket up and down. It sprays a good amount of hydraulic fluid when moving up and down. I am not a heavy equipment mechanic but generally handy and good with tools. I’ve talked to cat and they have priced to fix my valve body if I send it in to them. Before doing that, I was hoping to see if anyone else had opinions on my problem and if there are any other easier solutions then removing the entire valve body and shipping it to cat to fix. If anyone also has any advice for removing and reinstalling the valve body, it would be greatly appreciated. Thanks.
Nothing too dramatic. Looks like spool seals bad. What’s bad, it’s bing “C” and if I’m not mistaken, that is Rexroth MP series DCV, which was discontinued by Rexroth. So for parts you are pretty much at mercy of CAT. If your hydraulic reservoir sitting higher than that DCV - you going to have to drain it. Because when you pull that spool out - oil will not stop coming. What might be bad, the spool might get scratched out. And CAT might say that it is not available as spare parts. There’s company called QCC, they still make those valves, it is extremely hard to ask them to sell spool separately, but if you manage to get on Simone’s good side - she will talk to engineering and they will sell it to you. She did that for me.
The question is: is there enough room to work in place, is there enough room for spool to come out through the bottom. Or you would have to remove the whole bank.
Thanks for your response, TVS! The advice to reach out to QCC is also really good! This is what cat told me: “I would estimate $1800 to replace the 3 resolvers, reseal the lift section and test. If the lift section is beyond repair, it would go to $3800 to replace the section.” That’s if I send them the valve body. Is the spool the part circled in red from the part diagram? See photo. So you think I can just replace the spool and the o rings on it? Do you know if I remove it from the top or bottom? And yes that is the big question whether I can work on it in place or remove the whole valve body.
TBH I would inspect the spool carefully. It is unlikely to be damaged unless some foreign body has passed through the valve at some time, but even then the damage is not likely to be at the top of the spool where it could leak out of the housing. You may be barking up the wrong tree. Your Parts Manual photo shows a 9T0625 Lift Control Valve. That is for an early-model 416, not a 1WR-prefix 416C like you have. I don't know how the parts compare. See the attachment. I have highlighted what I would replace in your position. Check the condition of all the balls #22 and replace if worn. Give the check valve #23 a rattle to make sure the ball inside it is free to move, and replace if the ball does not move freely. You will also require the seals that fit in between the various sections of the control valve.
I had to replace two spools on D6N, and those things were under cover, nothing but thick level of dust. I have no idea how they got messed up. Boots were damaged on them though.
Plus we have another thread about another 416c and that one was “grinding hard” until looks like something broke in linkage. Those things get packed with crap to unbelieve.
See, no separate item number for spool. It means they will not sell you spool separately, you’ll have to get the whole section
Yeah I didn’t see a part number for the spool. I have two theories for what caused the failure: 1) machine has been sitting for a few years and I just started running it so maybe some of the seals went bad. 2) I was clearing some land with it and a branch got lodged under the machine ironically near the valve body. I didn’t pay any attention at the time, but there is a small chance it may have lodged itself against the spool thereby maybe bending it slightly?
Nige, thanks for the diagram. I was using an old paper book but it may be for an earlier model. So perhaps the solution is to replace all the seals that nige highlighted and also try to get my hands on a spool from qcc. Nige, do you think I can perform all this work with the valve body in place? Or do you think I will have to remove the entire valve body?
With a bit of contortion you should be able to get at everything. Not saying it will be easy though. There isn't one. Spools are not sold separately to the body because they are matched as a pair at the supplier. TBH I am almost certain that you will find the spool is fine. A very remote possibility. Seals go hard with age. This is very likely what you are up against.
I would advise against messing with resolvers in those. Those are internal hex, sitting recessed, most of the time they are rusty and hard to get out. I know they get sticky, but if you don’t need to mess with them - avoid it like a plague! I wouldn’t mess with anything bit seals spool, and centering spring cap. I would pressure wash/clean everything very good, and try to do it in place. Another thing that can affect those that leaking is high back pressure in return gallery ( return filter).
Hopefully you only will be replacing seals.
Are you sure the oil is coming from the spool valve? That seems like an excessive amount of oil to be leaking past a spool.
If his return filter plugged ( which probably is, because it’s cellulose and I don’t know whether that oil is milky or aerated) at higher engine RPM and seals destroyed - it’s possible
All I will say is make damn sure the leak, is where you think it is. I would get someone else in the operator’s seat and visually see that it’s leaking past the spool seal. It does look like your pictures, which are very good by the way, are taken in succession, and that it’s leaking out of the spool cap. You may be able to disconnect the linkage and lift that spool out and replace the seals in that. It does look like the same spool that I had to do in my 99’ Cat 416 and was able to do it in place but it was 35 years ago and I know I didn’t have to take that whole block out. I do remember having to loosen the bolts for the block and wedge it forward though. My CRS is not helping If you can change your own oil and replace a water pump, you can do this.
Thanks for the additional response, Harley Happy. I figured out how to upload a video of the leak and here it is: https://go.screenpal.com/watch/cTVwIDnfHIK It’s also worth nothing that the engine oil pressure light is on. I checked the oil dipstick and it is still full. Would the hydraulic leak cause the engine oil pressure light to go off?
Engine oil pressure has no connection with hydraulic oil, looks like you have 2 issues
Nige, where can I find the parts manual you referenced and marked up? I’ve been trying to find it online. I only have the paper edition for the 416 and not the 416c.
You need to search for Cat Publication reference SEBP2888. Here is a used one on eBay
Wow, that’s a leak and a half. You actually may be better off taking that valve block completely out. Is there any kind of plug or port right behind that rod linkage. That might be a cracked block. Your fluid looked a little milky, how cold has it been?