Case 1155D Hydraulic Control (3 spool) Valve Rebuild

[Bobcat Crazy]

Hi All!
I have been able to play with Sweetheart a little since I finished building the engine. (sorry I don't know how to put the link to that thread here, I wish I did). I had the time to take down an old tree that I had been wanting to remove for a while now. When I did I found that one of the track adjusters needing rebuilding and the clam function would not hold pressure very good. The clam cylinders had just been rebuilt right before the engine went out so I thought I would start rebuilding the spool valve.

Also I found a lot of O-ring pieces lodged in the screen filter when I cleaned it so that is another reason I thought this was a good place to start.

I found it is a little more complicated (and a lot heavier) than my Bobcat skid steer valve but it has not been that bad now that I have a good manual.

I have disassembled the valves almost entirely, I still have to pull down the intake/outlet section. I have not found much missing O-ring material as I thought I would (just the really small O-ring on the secondary shuttle valve on 2 different spool sections). There was a piece of tag tie wire on the valve so I assume it has been rebuilt before at some point. But it was a long time ago. Though I found very little missing O-ring material, all of them are very hard so I am sure they are not sealing good.

I am off of work the rest of the week so i hope I can finish this project and get Sweetheart ready to take something else down before Monday when it is back to the "Salt Mine" for me!

The only thing that concerns me is the adjustment of the valves. The manual says measure the distance from the top of the body to the top of the adjusting screw. I don't have any issues with that but I just wonder if the last person that played with this valve knew what he was doing and if he adjusted it correctly.

Some of the lock nuts on the adjusting screws are only caught by a couple of threads and don't come all the way through the lock nut. So this makes me think they were not adjusted correctly when I started on it.

I called the local CASE dealer today to see if the had a way to bench test the valve assembly and set the adjustments on it before it was reinstalled. They were as nice as they could be (which surprised me since I am not a big money spender with them) but they actually had a 1155 in the shop and said they did not see anyway that could be done.

So if you guys have any thing that you have learned about setting these from your years of experience feel free to jump in and share with a rookie!

Thanks ALL!

B-Crazy

 

[Tinkerer]

Section 8007 in the service manual covers everything needed to know to service the valve.

 

[Bobcat Crazy]

Hi Tink, and Guys!
I will agree that section 8007 has loads of info on the spool valve. And in a perfect world (or a machine that has been in a perfect world and not had things mismatched on it) that would be enough info to get things adjusted correctly when someone with experience is doing the work.

But with a rookie (as I am) when I find things that are not like what the book shows I am kind of lost. No real lost!
Check out the pics below, the two pics with the orange finger pointing at what should be the circuit relief valve and the anticavitation valve on the lift spool are nothing like what is shown in the manual on 8007-21. Nor does the spring housing have an adjusting screw in the end of it. There is just a plank plate on the bottom of the spring housing. (on the same page). See the pics below the two valves in those 2 holes are nothing like the others in that position on the other 2 spools.

Then on the bucket spool there is no coil or any of the things shown on page 8007-23 that is supposed to be in the housing # 20 on that that page.

I have all new o-rings and backup rings in all of the components and all of the adjustments are set just like it was when I removed it. The biggest thing I found was the o-rings were missing on all 3 secondary shuttle screw (o-ring at the ball end) and tall the rest of the o-rings were so hard that I had to cut them or break them to get them off.

All of the machined surfaces were in really good condition with no wear other than the plunger in the main relief valve item #13 on page 8007-19.

So all in all the whole valve assembly looks to be in good shape other than the 2 mismatched (sub) valve assemblies on the lift spool and the missing parts on the bucket spool.

Any guidance is much appreciated! I hope to get this HEAVY ASSEMBLY installed tomorrow so that maybe me and Sweetheart can play around a little this weekend!

B-Crazy

 

[Bobcat Crazy]

A couple more pics of spool valve.
B-Crazy

 

[Tinkerer]

Part of the problem is that the 1155D service manual covers both dozers and the tracked loaders.
So, you need to be careful that you are on the correct pages for your application.
I think the same valve is used in both machines with the exception of an additional section for the loader bucket.
A thorough search in the parts book would show the differences.
Below is your valve and the one I was looking at in the service manual.
It appears to be the same valve.

 

[Bobcat Crazy]

Good evening Guys!
Hey Tink you are correct that the loader and the dozer use the same valve plus or minus extra spools for the bucket, ripper, and tilt but the differences are minimal in the actual components of the valves. I have looked at every valve that I can find in the parts book and the service manual. So far I have not found either of the 2 shorter components I sent the pictures of last night. I have looked over and over because I thought I may have been missing them. But unless they are in a different section the 2 I am talking about are not shown in the books.

One other thing I have not found in the book so far also is a little plastic tank (kind of resembles a small radiator overflow tank on a car) located inside the housing that incases the spool valves. It actually right above the spool valves and under arm rest for your right arm. the funny thing is there is no access hole in the housing plates that you would need to add some type of fluid to the tank. The only way to add fluid to it would be to take off the metal plate which the arm rest bolts to.

That design is strange to me, but it does look like it was designed that way. It does not look like any kind of an add on. Check out the pic below I am interested in knowing what it is for.

I'm not saying for sure that this item is not in the book. I'm just saying I have not found it, however I have not spent even a fraction of the amount of time on this that I have spent looking for the shorter spool valve components.

Any ideas Guys?

 

[Bobcat Crazy]

The best I can tell it looks like the little hose from it goes into the top of the transmission.

 

[alrman]

The best I can tell it looks like the little hose from it goes into the top of the transmission.

Correct - oil fumes/vapor from the transmission collect in the tank & drain back to transmission.

Also - those adjustable secondary relief valves can indeed be checked on the bench by using a hydraulic hand pump.

 

[Bobcat Crazy]

Thanks Alrman!
Yes the tank was easy to find in the book once you told me what it was! And I was pretty sure there had to be a way to bench test/set the pressures on on the valve assembly.

My message to the service guys at the dealership was being translated through a receptionist so it would have been easy for the service guys to have gotten the wrong message, or I could have used the wrong terms when asking for what I needed.

Anyway now it is what it is. I am waiting for backup seal that goes behind on of the in one of these valves and then I will be able to try it out to see if my labors of rebuilding the assembly have helped it any.

Thankfully it is one of the screw out components on the valve assembly that this one little seal goes on, so it will be a quick fix when my order arrives. Hopefully it will come in sometime on Monday.

And being I did not get a bench test and set by the professionals at the dealership, if it does not work correctly, I will get some more reading time in with the service manual and hopefully learn something new about hoe these are adjusted with the valve assembly actually on the loader. I was really hoping not to have to learn about that!

I guess the biggest issue I found with the spool valves was the little o-ring on the secondary shuttle screw was missing. So being a rookie I don't have any idea how much that would have affected the pressures in the valve. Also there was a worn plunger in the main relief valve which I assume would have been leaking a little but I would think that it was very little. But anyway that was replaced to so hopefully I will see an improvement.

B-C