hi everyone. just wanted to see if i could get some info on an cylinder head i have. just purchased a older back hoe attachment and the seals were shot. its an old koehering 9md2 unit and the cylinder heads are a son of a gun to get out. it seems to have a notch in the side of the cylinder body that i can see the actual head moving as i spin it with the wrench. any clues how to remove this type of unit. any input would be awesome. if pictures are needed i will gladly post them. thanks in advance. i have tried looking up what this type of cylinder this is called to see if youtube had anything but i cant find any info on it.
This sounds like a wire lock style head, it uses a soft steel wire to key the barrel to the head. To remove it ,you turn the head until the end shows in the slot then pry the end up with a heavy pick and turn the head and it will push it out as it is turned. It sounds harder than it is ,after one you will be a pro!
thanks power guy! now when i turn it do i turn it so that the end spins out until i get the whole thing off the head? and is this call a "wire lock" so i can do a little more research. is this an older style unit?
Not sure wire lock is the proper term, might be a hillybilly term! Turn it a full turn and the wire will come out, then you will have to pull out the head. Often I use the piston as a slide hammer to knock out the head, it can be a chore sometimes to get them apart.
cool deal brother. now when you put her back together do you have to replace the wire used? or can you use the same wire. by the sounds of it, knocking the head off seems to me as if you have to replace the wire. sorry for the million questions. i just never had to deal with one of these units and i have to do 6 pistons on this freakin thing and they are all the same. thanks again for all your input!:thumbsup
I think they were sold under bradco, gehl, and others, the older units had the wire gland retainer and the newer had the screw in glands. Like repowerguy said, spin the gland until you can get one end of the wire ring out the slot, then spin and pull the wire ring until it's out. The tube where the ring seats sometimes gets a lip, using the rod like said (slide hammer) most of the time will get the gland out. You may have to clean the ridge up in the tube before putting it back together.
Welcome to HEF OG52. :drinkup Like repowerguy stated, this is hard to describe, but I'll take a stab at it. What both he and sheepfoot describe as a "wire" is close enough to call correct, more accurately it would be one of two designs, either it round steel rod, or it's square steel stock, I've seen both. But they both work the same way. A groove is machined into the cylinder can, and a groove is machined into the gland, what you called the "cylinder head". When the gland is fitted into the cylinder can these grooves match up. There is a small hole drilled into the groove that is machined in the gland. When the gland is installed, it's fitted so the hole in the groove in the gland can be viewed through the window (notch) that's cut in the side of the cylinder can. Then the wire, whether round or square, is bent with a sharp 90 degree bend, a hook, on the end of the wire. That hook is placed in the drilled hole in the gland groove. While holding the hook in the drilled hole, the gland is turned to pull the wire in. Once the gland is turned a full turn, the wire is fully sucked in the grooves in the gland and can, locking the gland in the can. The key to disassemble these things is clean the window so you can see what you're working with. Turn the gland until you find that spot where the wire ends. Look for the hook in the wire that's fitted in the hole to determine which way to turn the gland to remove the wire. Once you find that hook, and the opposite end of the wire, turn the gland in the opposite direction of the hook pulling the wire, you need the hook to "push" the wire. Nearby the hook you should see the end of the wire. Rotate the gland to access that end, take a small screwdriver to pry that end out of the window in the can. Once you get that end out of the window by prying and turning the gland, keep turning the gland and peel the wire out. But if the hook in the wire is snapped off, it really gets fun.
Usually you can reuse the wire retainer if you use some care as you remove it, just make sure you dress off the burrs from the pliers and make sure it's straight when you put it back together. I have bent a new hook on them in a pinch if yours looks cracked or is broken, the little it will shorten it is minor. Like sheepfoot said there may be a burred up edge to deal with, often can push the head in deeper and take a carbide tool and smooth it out, then slide hammer it out. It depends on how it is made if you can push it in deeper, but definitely remove all sharp edges before you put it back together. Hope this helps
thanks a lot you guys. this has been a tremendous help. all of your input is greatly appreciated.... now silly question the unit i have is a old girl and apparently the company changed hands a few times and its hard for me to find the seal kits for these units. what do you suggest i do. im sure someone on here has the same issue i am experiencing now with trying to find rebuild kits. 1) should i post in a sepreat section of this forum to try and find a little more info. 2) am i S.O.L. and just need to try and piece meal the kits... from what i gather there are a few other companies that make this same unit but the thing is are the internals the same.
Take the piston and gland to a hydraulic shop and they'll match you up in five minutes most likely.