941 Bucket Positioner Repairs

[Metalman 55]

Since purchasing this old machine a year ago, the bucket positioner has not worked & is on my bucket list of things to repair. The rod/clamp is missing that clamps onto the cylinder rod. The valve bracket has some damage to it, as does the guard. I would like to try to get the positioner working again if I can without spending too much on it.

I see there are three lines leading out of the valve but know nothing about how it works.

I was thinking for the rod & clamp that perhaps I could pattern a home made one after the one I have on the 955L that functions fine.

Can anyone explain how this system works & if I can test it before going to the work of making up the rod assembly? Maybe by pushing in the end of the valve where the little roller is, it should cause the bucket to "kick out" The valve has pieces of the mounting ears broken off, but I think there may be enough left to still secure it & keep an eye on it.

 

[Nitelite]

Wish I could help but someone had taken the entire bucket positioner off of my 951-C before I bought it. It probably got mangled about like yours so i guess that they just dismantled it. I wouldn't mind finding a replacement but if you never had it to begin with, you don't miss it. I have enjoyed reading your post on this forum.

 

[DMiller]

My Allis has a Return To Dig assembly but never gets used
Is a fall back to the old days of handfulls of controls where many were better with experience than the devices ever could be.

 

[Old Magnet]

View attachment 161303View attachment 161304

Since purchasing this old machine a year ago, the bucket positioner has not worked & is on my bucket list of things to repair. The rod/clamp is missing that clamps onto the cylinder rod. The valve bracket has some damage to it, as does the guard. I would like to try to get the positioner working again if I can without spending too much on it.

I see there are three lines leading out of the valve but know nothing about how it works.

I was thinking for the rod & clamp that perhaps I could pattern a home made one after the one I have on the 955L that functions fine.

Can anyone explain how this system works & if I can test it before going to the work of making up the rod assembly? Maybe by pushing in the end of the valve where the little roller is, it should cause the bucket to "kick out" The valve has pieces of the mounting ears broken off, but I think there may be enough left to still secure it & keep an eye on it.

Kind of a tricky little gadget. The control valve with the wheel works in conjunction with a slave cylinder and linkage in the hydraulic tank. Yes, I would think you would be able to test the unit by push/pulling the rod with the little wheel.

 

[tctractors]

This control is usual to be set to place the bucket to Level and not to a dig profile, as O.M. posted the control valve activates a small slave piston within the tank, to test this feature the bucket control needs to be pushed into Detent roll back position and the control valve pressed in, if it fails to work you will need to split open the hydraulic tank and free off the slave piston with a spanner on the linkage, I think it is 1/2 AF or 7/16 AF spanner needed, it will free off easily without any valve stripping and be well worth the effort of getting it to work.
tctractors

 

[DMiller]

Sorry for the Allis terminology
AC called it return to dig as one could raise the bucket arm on detent and dump a load with the linkage restoring the bucket to level and on the ground without a human pushing the levers.
Not really a return to digging profile but off full up detent and ready to return to work.

 

[Metalman 55]

I had a helper hold the little valve in with the roller on it after I began rolling the bucket back & leveler does not work. May take the small valve apart first to see if the problem is there first & then deal with splitting the tank if necessary after that.

 

[tctractors]

Don't waste your time, the fault is the slave piston being stuck inside the tank, all you have to do is wriggle it about and it will set free.

tctractors

 

[Metalman 55]

Ok..........thanks TC, the cold weather is setting in here now & I do all my work outside. I will likely plan to tackle this one in the spring when it warms up.

 

[Metalman 55]

Finally getting back on this bucket positioner project. All my linkage parts were missing when I bought the machine & the little lines going from the small valve mounted on the tilt cylinder were damaged & also disconnected from the tank by previous owners. Anyhow I am starting from scratch for the external mechanism linkage & since the Cat dealer cannot get certian parts & the ones they can get are horrendously expensive, I have decided to make my own. See the home made clamp beginnings that I plan to use. I am wanting to ask if any members have a working mechanism on an old style 941 or 951 that pictures could be posted of so I can get an idea to fabricate my own linkage. It will be a bit time consuming but this old 941 is a nice running old machine & I really want to get the bucket positioner working again......

 

[Metalman 55]

Lightly honed & put new seals in the bucket positioner valve located on the dump cylinder & it works fine now. There was one ear broken off of the mount that we repaired.

Split the tank & it looks pristinely clean inside! Discovered a small housing crack near the top of the valve body, but don't intend to do anything with that. Wonder what would have caused that? Perhaps like that since new?

Slave cylinder seems to work fine.

I am planning to go get some new hoses made up this morning as the old ones are a mess.

 

[DMiller]

As to the cracked ear
Location of the valve could be a clue
Rolled out spoil or a rock long ago or a loose bolt and wet weather to a freeze could do the damage seen

 

[kshansen]

Looks a bit different than the systems on the 988 and 966's but probably works about the same. One of the biggest problems with either of those seem to recall was getting all the air blead out of lines, just like hydraulic brakes. One bubble and it just won't work.

 

[Metalman 55]

Ok, so we got it back together minus the mechanical mechanism that I plan to build, as there was nothing except the valve body that came with the machine when I bought it about 4 yrs ago & it was seized. My right hand man Tony freed up the valve body & honed it a bit to clean & replaced a couple of seals. It seems to work free & fine now.

We tested the slave with air pressure this morning before closing up the tank & it works perfectly. Once all hooked up we cant get it to work they way it should. It seems the pressure line to the slave in the tank does not drop off once it is activated & the detent disappears.

In the picture, the lower black line that has the angled fitting is the feed from the cylinder (it is only about 12" lg) then the top black one runs to the slave about 12' of hose length, the white one is just a relief to the tank.

Anyone have ideas as to why the slave pressure does not seem to drop away after the external valve is activated & then released?

Ser #80H2988

 

[kshansen]

Maybe I missed it but did you post a S/N for this 941? Was trying to find stuff on SIS.

Not sure if this will help but here is the Sys. Op. pages for the bucket positioner for a 941

 

[Metalman 55]

80H2988.

 

[kshansen]

80H2988.

Well the pages I posted appear to show that as the "earlier" version which is the second half of the printout.

 

[Metalman 55]

We split the tank & adjusted the slave cylinder & it works perfectly now!

Next question; does anyone have a picture or 2 they could post of the mechanical actuation system that runs alongside the tilt cylinder on the machine as that is my next item to focus on? It is the old style as indicated by the previous post by kshansen.

I believe the mechanism would be similar on either the 941 or 951 (the early models).

A picture is worth a thousand words!!

 

[kshansen]

Well there are two things that might help a little:



Note that item # 10 is shown cut away so you can see the valve mounted to the cylinder. If you need a little more information I might be able to explain things latter.

 

[Metalman 55]

Any information would be most appreciated, even if any members have some actual pictures.

I wonder if Mark from S & S is still going? I wonder if he would have any such parts. Did you say once that you are near him??