H Cylinder Repair

[idaho04]

One of the H cylinders on my Bradco backhoe is leaking. Last time I needed to repair a cylinder seal I brought it to a local shop and paid $70 for the repair. I was thinking that I could do it myself. Here are my questions:
Where can I get the repair seal/kit? How do I determine which seal (size, type) I need? How do I open it? Where do I find out how to open it? Any oter hints/suggestions?

Any help appreciated.

 

[TedLaRue]

One type of hydraulic cylinder uses a "tie rod" design. It has three or four long bolts (tie rods) running the length of the cylinder (on the outside of the cylinder where they are plainly visible) holding end-plates onto the cylinder.



It's pretty obvious how to open those, so I'm guessing your cylinder has a "gland nut" (keep your mind out of the gutter!) on the end that the rod (I said, keep your mind out of the gutter) extends from. The gland nut has two holes in it. A special wrench spans around the rod and has pins that fit into those holes. I found one for sale in a local business that caters to industrial folks but sells to individuals too. I just now found one on the net for $16.22 + shipping, pictured below. The website is (as of 08/08/2007)

Auto Parts and Automotive Tools


Note the square hole for inserting a ratchet or breaker bar.

Installing the seal kit is pretty straight forward, but first check the cylinder walls and the rod for scoring/scratches. If either are damaged, the new seals will just get eaten up. You might be able to sand out minor scoring with emery cloth. But if you have deep scoring you'll have to replace them (or just buy a new cylinder). Remove the old seals and lay them out in order, then install the new ones in the same order.

Finally, after the repair, be sure to remove and clean your hydraulic fluid strainer. You may have to do that two or even three times (maybe 15 usage hours apart). When the seals failed, they may have contaminated the hydraulic fluid with very small bits and pieces of the seal, especially if the cylinder or rod were scored.

I ordered the seal kits I needed from the manufacturer of the cylinder because it was convenient, but you should be able to take the disassembled cylinder to a local place that sells seal kits and have them match it up. Check your yellow pages under hydraulics. Some NAPA shops do hydraulic work and sell hoses/fittings.

 

[Soundguy]

I like to do stuff myself.. but on big cyls.. it pays to have a pro do it unless you already have the tools and know how. Sometimes the gland nut just won't come off with 'normal' man sized tools.. etc..

Soundguy

 

[john_bud]

I like to do stuff myself.. but on big cyls.. it pays to have a pro do it unless you already have the tools and know how. Sometimes the gland nut just won't come off with 'normal' man sized tools.. etc..

Soundguy

That's why I have a 4' cheater bar. It also helps to hang my 220# off the end of the cheater and whap the cheater with a 3# hand maul. The shock will loosen it up.


BUT, I don't think that the cylinders on a Bradco are bigger than 3 or 3-1/2" bore. Just loosen the gland nut or cap while the cylnder is still on the hoe. You will typically need an impact or cheater bar for the piston nut.

H&D Distributors, Inc. Your Complete Source for Seals will have the seals. Decent prices and fast shipping.

They have a great PDF catalog with pictures. about 10 meg download.

 

[idaho04]

Thanks, Bud. The cylinder is 3" but quite ling. There are no obvious nuts on it but there is a slit near the end. What kind of tool do I need for it and what kind of motion do I do? Are there any pictures of the cylinder to look at? Once I see one open I'll be able to figure out how to do it.

 

[Soundguy]

Post a pic of it.

Soundguy

 

[tlbuser]

Thanks, Bud. The cylinder is 3" but quite ling. There are no obvious nuts on it but there is a slit near the end. What kind of tool do I need for it and what kind of motion do I do? Are there any pictures of the cylinder to look at? Once I see one open I'll be able to figure out how to do it.

The slit is for accessing the retaining ring. You need a spanner wrench to turn the gland nut CCW until you can see the end of the ring. Pry the end of the ring out then continue to turn the nut. Once the ring is removed, pulling on the rod end will allow the rod assembly to be removed from the cylinder.

 

[idaho04]

Here is the picture of the Bradco cylinder to repair.

 

[3RRL]

Ted,
Thanks for the link to the gland nut wrench. I've made some using round stock and dowel pins but this one is really handy.

 

[TedLaRue]

3RRL wrote: Thanks for the link to the gland nut wrench.

Rob, This site is great for sharing information. And I love your tag line. Reminds me of one a builder I know uses: "I may be slow, but I'm expensive."