Onboard Hydraulic Grenade

[chrisinnh]

It looks like both sides of that unit can be removed and swapped. So you could remove the relief valve and put it on the other side where I think it should be.

Can't do that. The side I'm currently using as "IN" is only tapped on one end. The other end is a closed casting:

I think someone hit the nail on the head when they said the hoe relief valve was doing all the work.

Almost certainly that's the case, but I'm not clear on the reason. I'd been assuming that it was because the hoe's relief was set a few PSI lower than the loader's.

But I'm still not positive that:

1. I have a relief valve at all (What is that thing?)
2. If it is a relief valve, that it's functioning correctly

Hopefully somebody will chime in to tell me that it is a relief valve, and that I'm just a knucklehead for hooking it up backwards.

/chris

 

[rbargeron]

You mentioned it looked adjust-y - try turning the screw in and see if it's already bottomed. Then turn it out and see what's in there. If it's spring loaded it won't be huge - just go slow and keep track of the order the parts as they come out. It might be a relief valve - they are sometimes adjustable with shims and/or springs. Some can be adjusted so they don't relieve at all - if it's screwed it down tight that would defeat its function.

 

[KubotainNH]

I don't think you get my meaning when I say they look like they can be swapped. The first picture shows your valve setup. The part I outlined in red looks like it could unbolt by removing the 3 nuts and swap with the same piece on the other side. Maybe it's the picture but it looks like there is a gasket there.

Now in looking at mine I see a big difference. I have 1 in hose and 2 out hoses. One comes out of the power beyond and heads back to the block to feed the 3ph. The other dumps right back into the resorvior. You only have one dumping out, maybe it doesn't matter but I figured I'd mention it. Pics below, sorry they don't look quite as nice as yours. I can e-mail you the higher res ones if you like.

Lastly, if you look at the picture I posted in another thread you see that I too have a large bolt thing on the left side. When I took it apart a couple years ago I realized it was not a relief valve, I don't think yours is either: http://www.tractorbynet.com/forums/...d1136338821-b6100-picture-800629-dscf0068.jpg

 

[chrisinnh]

Thanks very much to everybody who's helped me out so far.

Without you guys, I probably would have put my new (used) pump back into place and blown it up as well!

I finally took apart the adjust-y looking hex thing on my loader valve. Here's what I found inside:

Here's where that came from:

The needle/cone shaped thing on the left seats in the end of this bore:

Straight through that bore, we're connected to what should have been the pump.

When the needle is seated (by spring pressure), it stops fluid from flowing into the hole on the right side of the bore:

That hole leads to what should have been the return-to-sump line.

So, it's pretty clear that

1. I do have a pressure relief valve
2. I had it hooked up wrong

Finally, I've followed john_bud's excellent advice, and tested my selector valve to be sure that it doesn't have a closed center behavior midway through its travel, possibly costing me another pump.

I ran some compressed air through it while slowly changing positions. Luckily, it does not behave that way. There's a point midway through its travel where both output selections receive flow.

I was a little worried about getting the pressure relief set correctly, so I counted threads, etc...

But I don't know if it was ever right to begin with. So I plan to set it fairly loose, and tighten until the loader can lift 13 bags of wood pellets.

/chris

 

[Wayne County Hose]

You can get yourself a decent gauge and some adaptor fittings to make up a test kit for under 50 bucks. This way you are certain to get the pressure correct. It just may be the best 50 bucks you ever spent. I'll run thru a quick list of fittings and adaptors that should do most of your pressure tests.

1. Liquid filled 0-3,000 psi gauge.
2. -8, -6, and -4 JIC street run Tee.
3. -8 X -6 JIC reducer.
4. -6 X -4 JIC reducer.
5. 2 wire hose, -4, 2 feet long. -4 female JIC X -4 male JIC. One fitting, -4 female JIC X -4 female NPT. This adapts the fittings to the gauge and lets you position the gauge for visibility. -4 hose is cheap, so if you wanted this longer, do it. You could purchase other fittings as needed, but this would be a good start. Some metal caps and plugs wouldn't be a bad idea either.

Okay, maybe a little more than 50 bucks depending on where you purchase, but in my opinion, much cheaper than another pump.

 

[KubotainNH]

What's the scoop Chris? Is it fixed?

 

[chrisinnh]

I've just revisited this thread because I noticed some log activity on my photo server. Someone's followed this thread to my pictures.

...and it turns out that I never posted a post-repair follow up.

It turns out that I installed the valve backwards. My control valve is identical on both sides (both say 'OUT'). ...Except for the pressure release valve. That's only installed on one side.

I mistakenly ran the pressure line to the non-relief side, and the return line to the relief side.

I got a new (used) pump from the fine folks at Pittsburg tractor in TX, swapped the supply and return lines, and was able to move snow all winter without incident.

The onboard pump still doesn't move enough fluid for my taste, but it's usable. My loader is a B219 knockoff with 2" ID cylinders. They're too big, and make the loader slow to operate.

I'd been toying with the idea of replacing the tip cylinders with smaller ones, or ditching one of the tip cylinders and relocating the remaining one to the center of the bucket.

...But I think I'll just watch for a good deal on a joystick loader control with regenerative dump. That should speed things up enough to keep me satisfied.

Thanks for all the help.

/chris