Hydraulic Rebuild Question

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lyle11
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Hydraulic Rebuild Question

Postby lyle11 » Fri Nov 13, 2020 11:17 am

I am in the process of rebuilding my hydraulic block. So far it gone well and I was hoping to start reassembling it today.

My issue is with removing the Connecting Rod from the piston. I removed the lock nut and threaded a nut about 3/4 way on and hit it with a hammer. The nut went cockeyed and, although it’s hard to see in the picture, it damaged about 1/4 of 1 thread. I ran a cleanup die over it and it looks to me like it’s not damaged to the point that I can’t reinstall the locknut and be okay. However, I’m almost certain any additional attempts to remove the Connecting Rod using this same method will damage the threads to the point that I need new parts.

The reason for my rebuild was major leakage around the big piston at the front of the block. So, I’m hoping replacing the 3 big o-rings resolve it. It seems unlikely that the small o-ring on the Connecting Rod would be a major source of leakage.

I have or will replace every other o-ring. I did not spray penetrating oil or any parts cleaner on the part yet so I have not applied anything like acetone that would damage the o-ring. If I don’t replace this o-ring, I would be careful to only spray solvent on the piston and avoid getting any inside the area where the o-ring is located.

In general, the o-rings I have removed don’t look real bad. I do see damage on one of the 2 big o-rings that fit inside the block which would possible explain my leakage issue. The piston shows some wear, which is rough when scraped with a fingernail so perhaps I need a to look for a piston.

I’m looking for opinions from people who have done this procedure regarding any risk of not replacing this one o-ring.

Or, if someone has any idea on any other method to remove the Connecting Rod without special tools.

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lyle11
5+ Years
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Tractors Owned: 48 FCub
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Allis Chalmers B

Re: Hydraulic Rebuild Question

Postby lyle11 » Fri Nov 13, 2020 11:31 am

Now I’m thinking my bigger issue is the rough area on my piston. One of the o-rings that the piston passes over shows a rough area of wear. Hard to see in photos. I don’t have any experience with the hydraulics so I can’t tell what is acceptable or “needs replaced” as people say in NE Ohio. I can feel a rough area on the piston with my fingernail.

I have time to look for a piston, since I don’t need this tractor until next spring. I definitely don’t want to put it back together and have the same problem. I’m thinking that’s likely with this piston, since it looks like this piston is damaging the o-ring.

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Eugene
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Re: Hydraulic Rebuild Question

Postby Eugene » Fri Nov 13, 2020 2:46 pm

Check the cylinder for a rough spot wear area.

You may be able to polish up the piston rough spot with 1200 grit emery cloth. The cylinder, if it has a rough spot, perhaps can be polished up using a small ball hone.
I have an excuse. CRS.

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Glen
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Re: Hydraulic Rebuild Question

Postby Glen » Fri Nov 13, 2020 5:27 pm

Hi,
The piston and cylinder should look in good condition, and have no deep scratches or gouges, and feel smooth to your fingers. Feel the whole surface of both, anything that isn't smooth can cut or damage the o rings.
Use a good light to look in the cylinder.
Fine sandpaper like Eugene said, may help smooth them. It may take time to smooth them.

Be sure to put new Hy-Tran fluid on the o rings, and metal as you put it together.
Or other brand of fluid, if you have that.

If the piston is in bad condition, finding a better one would be better.
If the cylinder is in bad condition, you may need a different Touch Control unit.
A complete block can probably be found at JP Tractor Salvage, at the bottom of the page.

For removing the connecting rod, if it won't come out, maybe a press would work better, I don't know.
It's hard to say what condition the o ring there is in, it could be good, or it might not be good.

When putting it together, I would put some grease in the bushing on the forward end of the connecting rod, and on the pin, where it goes in the bushing. That is at the rockshaft. :)

lyle11
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Tractors Owned: 48 FCub
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Re: Hydraulic Rebuild Question

Postby lyle11 » Sat Nov 14, 2020 9:36 am

Thanks Eugene and Glen. The piston has a bad spot and it looks like I’d have to remove too much material and create a low spot to fix the bad area. Another forum member has one but needs to check the condition. The cylinder has some light grooving in line with the in and out motion of the piston. It appears to me that a hone would smooth it. I may have a block I can buy but the condition of the cylinder needs to be checked.


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