OK, I have one more tracklayer, which I call Allis. When I bought Allis she had a big J-D backhoe on the back, and a six way blade on the front. The way the hydraulics were set up you had to kill the engine and detach the main hydraulic pressure line from the blade control valve box and attach it to a pipe that went out to the backhoe hydraulic controls.

Well I had to have a new pump fabbed because the old one was so worn out that as soon as the hydraulic fluid got hot I lost all pressure and couldn't dig with the backhoe. This was a challenge because the pump actually mounts to the rear of the engine via a gear, who knows if this is something off a WWII battleship, as some warships ran a 3 cyl Detroit Diesel for some hydraulic operations, or so I am told.

I'd like to set this up so that the engine doesn't have to be shut down to switch from the blade to the hoe, but I am scared about installing two shut off ball valves as that could potentially lead to both off and a blown line, 2000psi oil into my leg, or worse. In theory both valves could work if only one was shut off at a time, but there has to be a better way. The last picture shows the coupler for the blade control oil line above and below right the pipe fitting they have going back to the backhoe.

So, any suggesetions?

P.S. Sorry, I know this is a Caterpillar site, so let's just pretend this thing is yellow and not AC orange.

From what I can tell you just need a diverter valve to switch the flow

Yes. a diverter valve should take care if it, then there is no off, just one circuit or the other. Is this an open or closed circuit hydraulic system, just curious, the diverter valve wouldn't care.

OK guys, thanks. I will look into a diverter valve. As you can tell, I know very little about hydraulics so thanks a bunch.

Try www.surpluscenter.com That's where I get most of my hydraulic goodies.

I had an old John Deere backhoe which had the pump pressure line go through the loader valve body, then out to the hoe valve body, then back to the tank.
Maybe he could go that route also?
Both accessories would still work.
When you are digging, you want to raise the blade/bucket to be able to push yourself ahead with the hoe.
One less valve to operate twice.
Make sense?

To go thru one valve and then on to the second is a great way to do it but the first valve set must be a "power beyond" valve bank or the flow will return to the tank at the first controls. That being said many valves can be converted to power beyond. I have done this with my old Fordson Super Major tractor backhoe.

Thanks guys I am really weak on figuring out hydraulics and I have no reference or idea what the models are on this old machine. I will examine the J-D hoe and see if there is a model number or serial number, I haven't seen anything identifiable on the blade controls and have no idea if they are oem or custom. Would it make sense to plumb directly to the backhoe and use the return line into the high pressure inlet for the blade? I would have thought the backhoe needed more pressure than the blade to operate. I have found a pressure adjustment for the blade next to where the hydraulic line connects.

If your hoe has a power beyond hydraulic control it will work by plumbing through the hoe first. If not the diverter valve is reasonably cheap and easy. It will have a knob to simply pull and push to select the loader or hoe for your pump flow. I just replaced a leaky 1" diverter on a log loader for $94.00 You an also get the diverter valve in 12 volt if you want a switch instead of the knob which would allow more flexibility in placement. Not sure about the reliability of the 12 volt ones. I believe they need continued power to hold one way.

I just wanted to make mention the John Deere used "closed center hydraulics" which maintains full pressure all the time, that puts the pump into "destroke" and moves only the volume required at operating pressure. I don't know what valves you have, but I just thought you should know. Tad