Hi, We have a D41E-6 dozer (5400hrs) control valve #723-23-10300. Its got a pretty good leak on one of the valves, and I have also noticed that the blade is not tilting as good as it used to. (requires more force to tilt) While I have replaced a lot of hoses and even rebuilt the Hydraulic pump, this control valve looks intimidating. Is this a matter of taking out those allen screws, pulling the valves out and replacing some seals, , or does the whole control valve need replacing?
With only 5400 hours I wouldn't think you'd need a new control valve.
Thanks Dave. Thats good news. Its going to be a happy new year after all. I dont use it that much, so it sits a bit, so maybe thats why its stiff, but do i need to pull it out to replace what ever (orings or seals) that are under those allen wrench screw caps? its got a pretty good leak on that middle valve.
Would be best to at least get pics. of how the spools come apart in case there are small parts that could get lost. A member on here may have a manual and/or have experience with them.
I have the owners manual, service manual, and parts book. In case i missed it, I couldn't find no break down of it.
I did find these, but still dont tell me if I am safe to take out while on machine or should i pull the whole valve?
From my past (limited) experience I can say water (moisture) is one of the reason these valves develop leaky seals, especially if the machine sits idle for long periods of time, if you find that to be the case, with the tolerances being as tight as they are in an hydraulic valve one or both the barrel and/or the spool will likely be scored, without knowing from the pic how hard it is to get the entire valve bank out on a bench it's probably going to have issues started with the other valves and would be advantageous to have the valve bank where you can rebuild the other valves all at the same time. Also if you find scoring a seal replacement most times don't last very long, JMHO, others may have a less grim story to tell.
Thanks Mcrafty. Appreciate that.
You haven't stated where the oil is leaking from or too. It is a manually operated valve so oil leaking externally is usually from the spool seals. Most of the times those are just O rings underneath the retainers that you can see where the spools show out of the block. Those seals end up getting wear from the dirt that sits on top of the collar and works its way into the O ring. Those are easy to replace with the valve inside the machine. Just pull the pin on the linkage attached to the spool and hold it out of the way. Take the two bolts out of the collar and pull it up over the spool and you should be able to see the O ring. What makes you think that it is taking more pressure to work the tilt circuit?
John C. has a much better diagnosis than I I have zero experience with Komatsu, I get what experience I shared from a couple of different John Deere dozers and a Case TBL I've owned over the years, That's why I stated up front my experience is limited. Lots of good experienced help on here that'll pull you over the hump with what ever you have for problems. Good luck, I hope it's as simple as John says.
Those valves are all about the same. The spools are always standing straight up so all the dirt just naturally falls on top of the seals. Water mixes and makes grinding compound and soon enough they leak. I check all the dozers for it.
Sorry about that. You are correct it is the spool valves. I didnt know what they were called. Perfect John C. Exactly what i wanted to hear. I will get those linkages apart and swap those orings out this eve. I was picturing me taking off those allen bolts and springs flying everywhere! As far as the tilt circuit, it just takes more pressure from the hand when are trying to tilt the blade in or out. I tried spraying some wd40 on them and that limbers it up, so it may just be again, the same orings.
My D41E-6 is doing the same thing with the tilt. if you try to tilt clockwise there is a lot of pressure working against the control lever. once you get it to start to move it will work fine for a while but if it isn't used for a few minutes, it goes right back to being stiff again. It definitely is hydraulic, not a sticky mechanical linkage. Mine also leaks thru the seal on the tilt badly. oldwhiteman have you been able to get yours repaired and get the issue to go away?
I wonder if the seal on the bottom portion of your tilt spool is leaking, causing a buildup of oil in the end cap. When you try to force the spool down you have to displace oil as well as compress the centering spring. Just a thought.
Mr. Ellis if you click on this link you can go to my other post. I ended up taking mine off to rebuild it and in hindsight I should have left well enough along. I ended up breaking a spool valve and they no longer sell them. You will not find a used one. Nor will you find a used entire control valve. I ended up buying an entire new control valve. $6100. That's not counting tax or shipping. HeavyEquipmentForums
Did you look into having a new spool machined? I would think a good machine shop could make one and allow for it to be hard chromed to resist wear.
What's up with companies not providing replacement parts for (imoh) relatively new equipment? Deere is just as bad. I have Deere and CAT equipment, Cat doesn't seem as bad....YET, I don't call equipment in the 80's and newer old.
1980 was 43 years ago!!
I'm aware of that, I also know there are plenty pieces of equipment around that time still in use today, although they are getting harder to find...I wonder why that is? Oh wait I think maybe it's because some of those manufacturer have discontinued replacement parts some time ago.
Would you expect to walk into a Ford/GM/whatever dealer and get parts for a 1980 vehicle.?
I would expect to be able to source most parts for a 1980 Ford or GM vehicle, it's done all the time albeit a lot of those parts are sourced from out side of their own supply. As for the particular part the OP was trying to get to fix his valve bank, they don't now nor probably ever where available to fit his valve bank...they are manufactured as a set. I was speaking in a generalization when I commented about the lack replacement parts for equipment. It seems odd that a company would built something that for the most part will last as long as one is willing to repair it and not stock replacement parts for a reasonable amount of time. I get that they like to manufacture and sell new...but it's no secret that they make large profit margins with replacement part also. If they don't want to make those parts release their hold on them and let an aftermarket handle them.
I understand your point but in the case of vehicles vs equipment there are a lot more of the former around than the latter. I don't think it makes too much difference whether the manufacturer agrees or not, it's a case of whether there are enough potential sales of a particular component to make it sufficiently attractive for the aftermarket producers to manufacture. In the same way as the OEMs aftermarket producers are not going to manufacture parts simply to have them sit on the shelf for years "just in case".
Cat is better than JD for parts on older machines and typically goes back more years before making parts obsolete. They have Cat classic parts too which may or may not be worth buying depending on what it is.
I understand what you're saying Nige, It's just aggravating when you have a piece of equipment that has years of work in it and you can't by simple parts for it. But not everyone operates like I do I guess, I'm running the stuff they retired ..Lol
Yeah, that's kinda what I was going off. If they don't have a part they have a nationwide network they search and find whats available. Deere is terrible, at least the Deere dealer I have nearest me. Oh well, I'll just keep plugging along and try not to break anything.
JD had already started making some parts for 80's machines obsolete in the late 90's. I had an 87 355D loader (last year) and I can't remember what part it was but was not available any more. I think by law they have to supply parts for 7 years (maybe 10) after a machine is discontinued. Edit. Looks to be 10 years in Canada.
The JD dealer here used to have a yard full of parts machines and a used parts dept. They were part of a used parts network across N. America. Not sure if they still do it or not.
Used to be a law in the US that said an auto manufacturer had to keep parts on hand for twenty years from first sold. That didn't apply to anything else. In reality most of everything else is a custom build. You want a log truck, printing plant, tug boat, overhead crane in a building, bottling line for your cola, plainer mill and on and on then expect that you will be dealing with machinists and fabricators to keep that stuff running. You will be a very valuable individual if you have a contact list of who can make something for you.
Welder Dave, we checked with several machine shops and was told it would be impossible to machine one of these. These spool valves also has a hole inside of them. I guess they are molded in the factory. And I was told this is a 1998 year model machine. Good news is I have a used control valve assy. for sale now, minus one spool valve.
I was told the spool and the barrel are a matched set ie: not interchangable, It would have been nice to be able to purchase just the one spool/barrel you needed but hey, probably not enough demand to maintain singles, you probably were lucky to find a complete valve body now on a 25 yo machine, things being as they are with replacement parts. Might want to devise some way to keep water and dirt from accumulating on top of the new one.
10-4 on that Mcrafty1. That makes sense on them being matched. had not thought about that. Every dealer we called could get a Whole new valve. Just hard to believe there wasn't a used one around. We have just use this dozer on the farm since we had it. I still stand by it. I like that it has the joysticks but its mechanical and not electrical. Its been a good machine. And it takes the same oil filter as my truck, so thats a plus. should be through with it this year.