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Vulcan 8 x 8

CarterKraft said:
It will lose servo pressure and braje pressure simultaneously, shifting to "park" and setting the brake. The drive pressure will go over the cross over relief valves in the motor? and slow very quickly to a stop.

Not something you would want to do a lot.
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Not quite following. What is servo and braje pressure?

Maybe I asked incorrectly. If I shut down the pump with the selinoids, I assume the swash goes to flat or neutral. Of course, the motor would become a pump and keep the fluid moving, but I don’t think the drive pressure would have to go over reliefs. But maybe I’m wrong. When the swash is flat, can it not just spin freely? If so, is there much drag on the motor.

The second part of my question is on the parking brake. If after I stop the pump, I release the pilot pressure to the brake, it would automatically go on. I kind of assume it’s not good for the brake.
 
WaterH said:
Not quite following. What is servo and braje pressure?

Maybe I asked incorrectly. If I shut down the pump with the selinoids, I assume the swash goes to flat or neutral. Of course, the motor would become a pump and keep the fluid moving, but I don’t think the drive pressure would have to go over reliefs. But maybe I’m wrong. When the swash is flat, can it not just spin freely? If so, is there much drag on the motor.

The second part of my question is on the parking brake. If after I stop the pump, I release the pilot pressure to the brake, it would automatically go on. I kind of assume it’s not good for the brake.
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Servo pressure is charge pressure

Pump at flat swash angle is not in neutral, the pistons move neither in or out so there is no flow back through the pump.

The drive pressure has to go over relief or some sort of auxiliary "coast" valve.
That wouldn't be normal...
 
CarterKraft said:
Servo pressure is charge pressure

Pump at flat swash angle is not in neutral, the pistons move neither in or out so there is no flow back through the pump.

The drive pressure has to go over relief or some sort of auxiliary "coast" valve.
That wouldn't be normal...
Click to expand...
Hmmmmm,

Would this be differnt on a hydrostatic tractor? When I let off on my tractor, I’m not sure what I’m doing. Is there some kind of torque converter in between?

Another question,

In the specs for this thing, they talk about 4 different pressures.

1. 350 psi. Charge pressure
2. 1500 psi. Brakes
3. 2000 psi Wheel lifts
4. 6000 psi drive pressure

I have over 350 psi from pilot pressure pump. I guess the brake pressure comes from foot pressure. I assume the drive system makes around 6000. But where would 2000 come from?
 
More work. New alternator. This color is supposed to give me more amperage and an extra 25 psi on the hydro pumps.

IMG_1723.jpeg


One belt is tight and the other is loose. Same number on the belts. I don’t see how the alternator can be crooked, so maybe one belt is stretched? POS belts stretched after only 30 years.

Tested my remote control and every thing worked. I was ready to take it off the Jack stands for a test drive and realized one gearbox was in high and one was in low. So went about plumbing a selector in.

IMG_1724.jpeg


Just using one of the joy sticks for the gearbox. The other is on hold till I get some fittings to control the motor. Right now I just plumbed a loop on that side in case some one were to accidentally pull that stick and shoot hydro fluid all over.

I just got done with this when it started raining. First drive might be postponed till tomorrow.
 
ThePanzerFuhrer said:
Is this a closed loop Hystat system? I second carterkrafts use a pwm control to stroke the pumps.
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IT LOOKS like standard Hystat controls too me, nothing special on the pump side.

The motor might have some load sensing displacement control shit but I wouldn't bother with anything until I established EVERYTHING was good and would once again operate.
 
WaterH said:
Hmmmmm,

Would this be differnt on a hydrostatic tractor? When I let off on my tractor, I’m not sure what I’m doing. Is there some kind of torque converter in between?

Another question,

In the specs for this thing, they talk about 4 different pressures.

1. 350 psi. Charge pressure
2. 1500 psi. Brakes
3. 2000 psi Wheel lifts
4. 6000 psi drive pressure

I have over 350 psi from pilot pressure pump. I guess the brake pressure comes from foot pressure. I assume the drive system makes around 6000. But where would 2000 come from?
Click to expand...
The tractor will have a coast valve which will allow some free-wheel to happen on decel.
That's not normal earth moving shit though so I'm going to making a lot of assumptions on its operation.

DRive pressure is restriction to flow, not constant.

The wheel lifts, pilot and charge will be cascaded relief valves (maybe)?
I'd expect separate charge pump from the rest, it will also provide cooling oil flow.
 
CarterKraft said:
The tractor will have a coast valve which will allow some free-wheel to happen on decel.
That's not normal earth moving shit though so I'm going to making a lot of assumptions on its operation.

DRive pressure is restriction to flow, not constant.

The wheel lifts, pilot and charge will be cascaded relief valves (maybe)?
I'd expect separate charge pump from the rest, it will also provide cooling oil flow.
Click to expand...
Maybe periodically bump the pages in this thread with the schematics, circuit pix so we don;t have to dig through 13 pages for the info.
 
ThePanzerFuhrer said:
Is this a closed loop Hystat system? I second carterkrafts use a pwm control to stroke the pumps.
Click to expand...

Yes, closed loop.

CarterKraft said:
The tractor will have a coast valve which will allow some free-wheel to happen on decel.
That's not normal earth moving shit though so I'm going to making a lot of assumptions on its operation.

DRive pressure is restriction to flow, not constant.

The wheel lifts, pilot and charge will be cascaded relief valves (maybe)?
I'd expect separate charge pump from the rest, it will also provide cooling oil flow.
Click to expand...

Could I spot a “coast valve”? What is a cascaded relief valve? Could I spot that?
 
WaterH said:
You and me both. My friend from south Florida saw the pics of the remote and said that I should convert it to radio control. I was thinking Who would make a remote control tank? lol.
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It would be a super easy task, and I think it needs to happen. Have it switch from manual to rc whenever you need.
 
irate4x4.com

Vulcan 8 x 8

How long was "the whole time" ? Must be pretty funny when you walk through the cord and unplug the vacuum, or the breaker traps back at the barn. :lmao: I'd be set up to run vacuum, remove fitting, install temporary plug,.. This time it was about two hours. Something’s don’t plug well. Or...
irate4x4.com irate4x4.com
 
It’s alive!

IMG_1726.jpeg


Just barely. It took about 20 seconds to move this far.

IMG_1727.jpeg


It has no power. I don’t understand. The engine is not laboring. It most be a pump thing. It barely moves in low range. It won’t move in high range. Even in the low range, it seemed like it didn’t want to go up this shallow hill. I’m not sure if the high/low range gearbox needs pressure all the time. When I went to go back up this hill, it wouldn’t go in low range until I pulled and held the lever. When I did this on the bench, I didn’t need to keep pressure on it.

The other problem is the wheel jacks won’t lift the machine. If I Jack it up with a floor Jack, I can lower the wheels, but it won’t do it solely with the hydro. Pilot pressure is obviously not enough.

I was thinking to myself that if I got it to move under its own power, I will commit another $3500 to the project. (I’ve got about $1500 in it now) it moved, but not enough for me to commit yet.
 
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WaterH said:
It’s alive!

IMG_1726.jpeg


Just barely. It took about 20 seconds to move this far.

IMG_1727.jpeg


It has no power. I don’t understand. The engine is not laboring. It most be a pump thing. It barely moves in low range. It won’t move in high range. Even in the low range, it seemed like it didn’t want to go up this shallow hill. I’m not sure if the high/low range gearbox needs pressure all the time. When I went to go back up this hill, it wouldn’t go in low range until I pulled and held the lever. When I did this on the bench, I didn’t need to keep pressure on it.

The other problem is the wheel jacks won’t lift the machine. If I Jack it up with a floor Jack, I can lower the wheels, but it won’t do it solely with the hydro. Pilot pressure is obviously not enough.

I was thinking to myself that if I got it to move under its own power, I will commit another $3500 to the project. (I’ve got about $1500 in it now) it moved, but not enough for me to commit yet.
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You're doing it right though, confirm you aren't throwing good money after bad.

No clue what's going on with the gear box.
If the motor was in max displacement it would be really slow but really strong. If it was in the minimum displacement it would lug the engine.

Was the engine at idle? It might have speed sensitive servo pressures. If it does as the engine rpm drops from the setpoint the pump pressure will drop accordingly, this gives you stall resistance, keeps from killing the engine during high loads.
 
CarterKraft said:
You're doing it right though, confirm you aren't throwing good money after bad.

No clue what's going on with the gear box.
If the motor was in max displacement it would be really slow but really strong. If it was in the minimum displacement it would lug the engine.

Was the engine at idle? It might have speed sensitive servo pressures. If it does as the engine rpm drops from the setpoint the pump pressure will drop accordingly, this gives you stall resistance, keeps from killing the engine during high loads.
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Engine was reved up. I don’t have a tach, but I’m guessing 2000. It has to be to get the pilot pressure up. I’m wondering if I need to bleed the system. I don’t have the resivour full. The resivour has about five lines that go in at the bottom and another five that go in about half way up. I have the fluid level a little above the half way lines. I think that the lines half way up are return lines, so I don’t think I’m drawing air in. But I guess I will fill it to the sight glass and look for some bleed nipples on the pumps. There are a lot of caps and plugs on the pumps that I’m not sure of their purpose.

As far as the wheel jacks, I’m thinking of installing a power steering pump on the engine just for the wheel jacks.
 
Bebop said:
What a fucking sight !!!!
This is awesome ! :smokin:
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My sarcastic meter is jumping.

Anyways, I dumped $200 of fluid in it and that brought it up to the middle of the sight glass. The level before was just about even with the top of the pumps. So there wouldn’t be much head pressure. Didn't find a bleed nipple, but there was an extra AN4 with a cap on each. I pulled the cap and some fluid started dripping. Can’t say it was coming out fast, but didn’t seem like any air was coming out, so I capped them.

The internet says you don’t really need to bleed a closed system, but you should fill everything before hooking up hoses. Who got time for dat? I got shit to do today, so I will let the head pressure bleed the system over night.
 
WaterH said:
My sarcastic meter is jumping.

Anyways, I dumped $200 of fluid in it and that brought it up to the middle of the sight glass. The level before was just about even with the top of the pumps. So there wouldn’t be much head pressure. Didn't find a bleed nipple, but there was an extra AN4 with a cap on each. I pulled the cap and some fluid started dripping. Can’t say it was coming out fast, but didn’t seem like any air was coming out, so I capped them.

The internet says you don’t really need to bleed a closed system, but you should fill everything before hooking up hoses. Who got time for dat? I got shit to do today, so I will let the head pressure bleed the system over night.
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As long as the charge pump is primed and making pressure it will flush the drive loops as the motors and pump barrels spin.
 
Sounds like its bypassing somewhere, as mentioned freshly bumping the schematics would be helpful.
 
Bebop said:
Your sarcastic meter is wrong. I'm genuinely happy to see it moving.
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If you saw how slow it went, it sure wasn’t exciting. I guess I should be happy it moved at all.

CarterKraft said:
Is there any valves or anything between pump and motor?
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Nothing along the hoses and nothing at the motors. Where the hoses hook to the pumps is very complicated looking. More so than what I would think. (Of course I don’t know shit) when I was looking for a bleeder, I found several “adjuster things”. Probubly some kind of reliefs. I will try to find or take a pic.

IMG_0587.jpeg


IMG_0585.jpeg


Bacho said:
Sounds like its bypassing somewhere, as mentioned freshly bumping the schematics would be helpful.
Click to expand...

I don’t think any of the literature I have shows that, but I will check. When I was first working on this, I watched a bunch of videos on closed loop systems. One of them was good and seemed to be just like mine. Of course I can’t find that one anymore.
 
Here's all my comments on what I can see.
IMO you don't need to adjust "Stops" they are set when the pump is on the flow bench and almost never require field adjustment. The Neutral setting can be adjusted if the pump "NEUTRAL" is out of whack.
The relief valves can be adjusted but you really need to know to what pressure.


1726759985269.png
 
I guess you don’t know what kind of pressure those pumps are putting out? If there’s nothing in between the pump and the motors, it shouldn’t be too hard to figure out.

I worked on those swash plate pumps before there’s not really that much to them. If you wanted to take it apart and figure out how it’s controlled.

The problem pumped that I I worked on, I found some of the “pistons “stuck
 
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