Used Backhoe Valve Source?

[jaluhn]

Looks like the valve body on my 723 Ford hoe (3500 tractor) is shot - I've got cracks between 2 of the valve bores on the front face and my attempt to weld it didn't work.

Any thoughts on where to find a good used valve? Not sure but I'd think most any open center manual backhoe valve should work - I don't mind doing some fab work to make it fit as long as the hydraulics work out.

Thanks,
~John

 

[Bern]

I'd be more interested in why the valves cracked. Did someone tamper with the relief valves?

 

[jaluhn]

Not sure but I think I have an idea. Originally it developed a crack on the front side (opposite the work ports) about 1/4" below the top face maybe 1" long. It looks like someone had messed with the spool seal plate on the adjacent spool and I think possibly someone had bottomed out the bolt causing stress in this area - not sure but the crack was where bottoming out the bolt would have stressed the casting. This crack was welded with the valve in the tractor and it seemed to be working well.

About 2 months later it developed the current pair of cracks between spools on the top face in the same general area that I was welding. I suspect welding the first crack caused stress that finally showed up as these cracks.

I did check the relief valve pressures and they were within spec IIRC. I think it's possible that the relief valve may be sticking causing a pressure spike before it opens, but I don't recall seeing anything when I was checking pressures. That is something I'm going to check once I get it back together for sure.

 

[sixbales]

Try the "dismantled Machines" section of tractorhouse.com

Click on "dismantled machines", then on "ford" and then on "3500". They have 14 3500"s listed, but not all have backhoes.

 

[jaluhn]

Turns out the reason it cracked so badly is because I was an idiot and tried welding on it not realizing it's cast iron. Whoops!

Hopefully getting a 555A valve next week to replace it with - closest thing I could find. Have to see how much work it takes to get that sucker to work.

The nice part is that I can pull the 4 ford o-ring seal to JIC adapter I had to use at the valve when I replaced hoses and use them on other hoses I need to replace.

 

[jaluhn]

To follow up on this, I did finally get the 555A valve I was looking at and have installed it to replace the cracked stock valve. The 555 valve is significantly larger than the 723 one and requires some modification of the mounts and control linkage did it's not impossible. It is setup with a power beyond port which I connected to the loader valve and ran a new return hose. All ports on the unit are SAE face o-ring, so adapter were needed on most hoses. My unit has already had most of the hoses replaced with JIC type fittings, so this was not a major problem - if you're trying to use the stock hoses it might be more difficult.

I also discovered that a JIC-10 bulkhead fitting works well as an adapter to the female o-ring type fittings that were used stock, and is far cheaper than the custom made fitting. I used one of these with an o-ring sized to fit the OD of the female fitting (don't remember what size, just got a kit and picked what fit) and seems to work well - no leaks yet anyway.

The backhoe feels a bit smoother in the operation with the new valve as well.

The 555A valve I have is a off a 2 stick, so the spools don't match up right - I connected them up identical to the original valve, but this means that the port relief valves aren't in the right spots. I am planning to disassemble the valve since it's sectional and put the sections in the correct order to fix this problem eventually. The port reliefs and main system relief pressures are also higher than the stock valve and would need to be adjusted - I haven't done this yet either.