Hydraulic cylinder rebuild

[motorsportsfan]

Hi, I own a JD 4400 tractor, with a 420 frt end loader. One of the bucket tilt cylinders is leaking badly. My question is, how do I take this cylinder apart? I know that the end cap (Hydraulic cylinder rod guide), has to come off first, but there in an internal snap ring holding it in place. I can't find a way to get to this snap ring, let alone compress it. Any help will be appreciated. Thanks

 

[BobReeves]

Does it have a slot in the side of the cylinder? If so you turn the end cap and the ring will roll out through the slot. If not I can't help..

 

[motorsportsfan]

Thanks for the reply. Unfortunately, mine doesn't have a slot on the side.

 

[Hooked_on_HP]

Alot of times you are better off taking it to a hydraulic shop. Do you know what caused the leak. Is there is a rough spot or a ding on the shaft,or a dent in the bore.If there is putting new seals in will just be a waste of time and money.

 

[ns_in_tex]

I think some cylinders have a small hole through the cylinder in line with the snap ring. If you have this hole, use a small punch to push on the of the snap ring untill you can get a screwdriver under it.

 

[dfkrug]

I have rebuilt cylinders on my JD 70A loaders. That unit has
been superceded by the 420, I think. Anyway, if the cyls go
together like mine, then you need an internal snap ring pliers
with bent tips and you usually have to pull on the rod at
the same time you compress the ring.

As for leaks, it is common for the rod seal to have paint flakes in it, which means you have to pull it all apart, but no
new parts are necessary. BTW a rebuild kit from JD is about
$40.

 

[kennyd]

</font><font color="blue" class="small">( Hi, I own a JD 4400 tractor, with a 420 frt end loader. One of the bucket tilt cylinders is leaking badly. My question is, how do I take this cylinder apart? I know that the end cap (Hydraulic cylinder rod guide), has to come off first, but there in an internal snap ring holding it in place. I can't find a way to get to this snap ring, let alone compress it. Any help will be appreciated. Thanks )</font>

I rebuilt the cylinders on my 410 loader, and had this same problem so I went and talked to the mechanic at my dealer.
When you buy the rebiuld(seal) kit from JDParts, in the package there is a orange piece of plastic, like a ring. You put that ring in the groove of the cylinder body where the snap ring is. Then you pull the piston out (or you can hook up compressed air to help) The plastic ring lets the snap ring slide past the groove.
I got one in each rebuild kit, but only used 2 of them to rebiuld all 4 of my cylinders

Clear as mud?
Hope this helps...

 

[RobJ]

I've never used a special tool but just my own way. I use a metal scribe/pick which basically looks like an ice pick tip. It'll take 2, usually the second scribe will have a 90 on the end. When I was a mechanic Snap-On Blue Point had several scribe tips, one set I have they are interchangeable. You use the point to get under the snap ring, then use the second to hook it, slide it around and pull the ring out. Last time I did one in the field I only had one scribe. After getting in a little I used a small screwdriver to work it out. No damage to the ring at all. Some packing/seal kits come with a new ring. They do wear if they are old.

Pic of Snap-On scribe/pick set I have

 

[kennyd]

Yes Rob, you are correct, but this is not a regular snap ring. It is not flat, but round, and there are no holes to grab, and this ring would have to be compressed, not expanded to allow dis-assembly of the cylinder. There is no room for tools in there, I even tried some aluminum sheet that I had to wedge in there to get the ring to slide past the groove, but it was a futile effort at best!
The plastic tool/ring they give you in the kit is the trick, and each kit was only about $15.00 or so and included all the O-rings and seals.

 

[motorsportsfan]

So that's how it is done! Thanks. I'll go buy a kit in the morning. Sad part about this is last fall I had a lift cyl. leaking. I couldn't figure out how to pull it apart, so I took it to a local hyd shop. They rebuilt it for me, for only $170.00! I told myself never again. Thanks again.