Case 644 loader repairs

[Eugen]

Last night, unplanned, took a look at the lift cylinder that leaks more heavily. Disassembly was a bit of an IQ test. There are two retaining rings, flat and coiled like a flattened piece of spring. Not knowing about them made it tough to figure it out, hard to see what's there.

Outer most retaining ring.

Second coiled retaining ring. Hard to get this one started. Used a 90 degree angled sharp poker.

Once the retaining rings were out, the rod and gland came out but got stuck at the end. Was not sure if there was another thing holding it there by design or just stuck.

After some pondering and a few bangs it came out.

The piston is made of aluminum and it's got fairly heavy scratches.


The piston nut takes a 7/8 socket and was easy to undo with a 1/2 inch drive 18" long breaker bar.

It wasn't obvious to me but the piston is threaded on too. Don't use a puller like I tried before I clued in. Luckily I didn't damage it. After heating it up with the propane torch the piston unscrewed by hand.

All is apart now.

Interesting the use of the bronze bushing there.

On to sourcing a seal kit. It would be nice to not pay nearly $100 per kit though.

[DavidBarkey]

@Eugen
The bronze bushing in the head gland is to keep the rod from being damage / worn do to the wieght and impact jarring when in use those cylinder are not lite .
The nut on the rod end is lock nut , Make sure loctite just same .
Try Sunnyside Hyd. , They may have them in stock . Take the piston and gland with you . By the size of that grove in the piston I would say it most likely is suppose to have backers on each side of the o ring . Are you able to cross referance those cylinders to a parts diagram ?
That scoring is no big deal on the piston , Just csmoth it out , debur and make sure there is no marks in the bore or rod and you are fine .
Like Spike mentioned check and remove any bur at the top of the cylinder tube that might nick the seals going together . Other than that the worst part is done , you got it apart that alone can be a night mare some times .

[Spike188]

Like Dave said, take the gland, cylinder end cap, old rubber and wear rings to a hydraulic rebuilder/supplier. They will likely have everything in stock. For around $200 all 7 cylinders and corresponding valve body o-rings, wear rings, and cup seals were replaced on my 646bh.

[Jancoe]

Eugen. Over on the other site I remembered Lionel posted about www.grizzlyseals.com. They are making seal kits for our loaders. Places in US and Canada. I'd give them a call and see what they could do for you.

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[Eugen]

Thank you guys! This is helpful. The o-rings I measured and are standard sizes: dash 113, 214, 224, and 326. Missing were the backup washers, like you said Dave, and one wiper seal. The one wiper seal nearest the outside of the gland was crumbly.

What's not clear to me right now is why the bronze bushing is sticking out about 1/8 and where the missing wiper seal goes, before or after the interior o-ring. Maybe it doesn't matter..

[Eugen]

There's a posting on mtf, probably by Lionel, about grizzlyseals.com

Steering cylinder- JIC-648 steering kit. (Oring/seals/wipers rebuild kit for steering cylinder)

Bucket cylinder JIC-18574. Loader cylinder JIC-41499

Price wise, you'll be quite pleased!

For 644's, 646's & 648's serial numbers, (648 prior to 14076828)

I'll give these guys a call.

@Spike188 and @DavidBarkey after my last experience with the local shop near me I prefer to go elsewhere.

[JSinMO]

@Eugen if you don’t mind would you let us know what you find out and what pricing is like? If they are good to deal with I’ll probably be calling them too!

[Harry]

I’ve never purchased seals from Grizzly before. For my front loader cylinders on the644 and the 646 I used Barneveld Imp. I called Grizzly when I was looking for seals for my backhoe cylinders. They couldn’t help me. So I ended up going to a local hydraulic shop and sourced the seals from them at a very reasonable price. I think if I was looking for seals again I would go back to the local shop before ordering and waiting for them to be delivered. Harry

[Eugen]

@JSinMO yes, of course.

[Eugen]

Called grizzly, offices closed, hibernating.

Disassembled the second cylinder which gave some clues how things should be. Like no protruding bronze bushing and order of wiper seals inside the gland. Heated it up and put snow inside the bushing, then pressed it in. Used the adjustable reamer to bring it back to size as it no longer slid on the rod.

Also, in case you're wondering why I write as detailed as I can is in hope that it will save effort and grief to someone who will need to do this in the future.

The second gland shows the bronze bushing flush, so the other one must be pressed in.

This shows the order of the two wiper seals and the o-ring. These were missing on the other gland.

The profile/cross section of the wiper seals.

Both bushings are flush now. When it was not flush, the width of the groove housing the inner o-ring and wiper seal was too big. Seeing the second gland clearly showed how things should be.

This reamer is adjustable between 15/16 and 1-1/8. The way it changes thickness is by turning the upper and lower nuts. As the cutting flutes move up and down the cutting thickness of the reamer changes.

Adjusting it the tiniest bit at a time, cutting, then testing it on the rod ended up with a nice fit. Don't know what I'd have done without the reamer.