Steelhead ES1000 winch slipping

Wdeertz · 09-28-2023, 11:01 AM

I replaced the dynema line on my steelhead ES1000 davit last year. Prior to replacement all functions on the davit were 100% working. After line replacement the winch line would slowly extend while under heavy load. I suspected this was due to air in the hydraulic lines. Looking at the manual it says the hydraulic lines are self bleeding after running the line in/out 3 times which I did. The slippage has been getting progressively worse over the last year so not sure if my issue is air in the line or some other issue. While looking at the central manifold/pump I noted two of the line have what appear to be valves on them. Not sure if these lines are for the winch control or the boom or extension. Both boom and extension movements fully hold under load.

Anyone with experience with this davit that can offer some suggestions on possible solutions?

bkcorwin · 09-28-2023, 02:27 PM

The valves you mention (valve is a generic term and could be lots of things in the sense of a hydraulic system) but I assume they are needle control valves. They are commonly used on cranes like that on the slew or rotate function to slow the speed of the rotation. This is because the rotary motor needs less flow rate than the cylinders to perform at an adequate speed.

If its really leaking you down and not just air you may just need to have the seals replaced on the spool in the valve that controls your linear winch

Wdeertz · 09-28-2023, 05:01 PM

Quote:

Originally Posted by bkcorwin

The valves you mention (valve is a generic term and could be lots of things in the sense of a hydraulic system) but I assume they are needle control valves. They are commonly used on cranes like that on the slew or rotate function to slow the speed of the rotation. This is because the rotary motor needs less flow rate than the cylinders to perform at an adequate speed.

If its really leaking you down and not just air you may just need to have the seals replaced on the spool in the valve that controls your linear winch

Thanks for the explanation. I’ve enclosed a few photos of the valves I was referring to. Your explanation of controlling the hydraulic fluid flow makes sense. I don’t know the color codes used by steelhead for the various hydraulic lines but suspect the lines with the valves is for the rotation.

Are the seals you mention behind what appears to be servos on the main manifold? I don’t have a schematic of the pump but it looks like what I think are servos unscrew off. Are the seals behind there?

bkcorwin · 09-28-2023, 10:19 PM

Found a manual. Looks like i was right that the third from the top with the flow control valves is the slew function. Looks like the top one is the winch.

https://www.advantecglobal.com/wp-co...RevH-small.pdf

You should be able to disassemble the solenoids and pull the spool out of the valve. Might be best just to call steelhead and see if you can get a parts kit. Its probably some standard off the shelf thing.

Bmarler · 09-29-2023, 08:59 AM

The brown cubes are just coils. Unscrew the black cap on top and they slide right off. (As long as the wire length is long enough)
Then you’ll see a smooth shaft with a hex at the manifold end. That will unscrew and the cartridge will come out. ( as will a bunch of fluid if the manifold is the low point.)
Usually, it’s just some standard size o rings in there. Keep it all surgically clean as you reassemble.

Wdeertz · 09-29-2023, 11:47 AM

Quote:

Originally Posted by Bmarler

The brown cubes are just coils. Unscrew the black cap on top and they slide right off. (As long as the wire length is long enough)
Then you’ll see a smooth shaft with a hex at the manifold end. That will unscrew and the cartridge will come out. ( as will a bunch of fluid if the manifold is the low point.)
Usually, it’s just some standard size o rings in there. Keep it all surgically clean as you reassemble.

Thanks for the info. I took out the cylinder for the winch control and don’t see any obvious damage to the o-rings but figure that must be the culprit. I can see how the coils direct the hydraulic fluid to control direction of the line. I have a call into Steelhead to order new seal kits. The other davit functions aren’t currently leaking but will order spare seals as it’s likely they may leak in the near future.

Will report back after I replace the seals to confirm this fixed my problem.

Wdeertz · 09-29-2023, 12:06 PM

Upon closer inspection I can see the blue plastic bushing under the o-ring has a small crack. This must have been allowing the fluid to bleed.

Anyone know if there are any internal seals on this cylinder? Waiting on the expanded parts diagram from steelhead.

bkcorwin · 09-29-2023, 01:01 PM

So, what I'm assuming is a backup ring for the oring may just be a split ring. Otherwise you can never replace the backup rings.

So the crack may be normal. That said, its hard to tell when o rings have failed as just progressive wear can cause leaks that you cant see in the ring.

Wdeertz · 09-29-2023, 01:14 PM

Quote:

Originally Posted by bkcorwin

So, what I'm assuming is a backup ring for the oring may just be a split ring. Otherwise you can never replace the backup rings.

So the crack may be normal. That said, its hard to tell when o rings have failed as just progressive wear can cause leaks that you cant see in the ring.

Yes I removed all the o-rings and backups and see they are split. So what I saw was normal. Still trying to determine what o-rings part numbers.

Maybe you can help my understanding. As I understand the mechanics the coils cause the inner rod to move and direct the fluid in one direction or the other. Wouldn’t there also need to be internal o-rings to prevent the fluid to bleed between chambers?

bkcorwin · 09-29-2023, 01:36 PM

Don't believe there should be any internal seals. Google hydraulic directional spool valve diagram and it will show you how they work.

Quote:

Originally Posted by Wdeertz

Yes I removed all the o-rings and backups and see they are split. So what I saw was normal. Still trying to determine what o-rings part numbers.

Maybe you can help my understanding. As I understand the mechanics the coils cause the inner rod to move and direct the fluid in one direction or the other. Wouldn’t there also need to be internal o-rings to prevent the fluid to bleed between chambers?

Wdeertz · 09-29-2023, 02:27 PM

Thanks, yes found a good description/diagram at this sight https://www.powermotiontech.com/hydr...control-valves, now better understand.

Bmarler · 09-30-2023, 12:08 PM

Just thought I’d mention, you’re on the right track doing the spool valve first, but it could also be the hydraulic motor at the winch itself bypassing internally. Rebuild for that shouldn’t be too tough either. Surprising there’s no fail safe mechanical brake on it.

bkcorwin · 09-30-2023, 12:56 PM

The es1000 uses a linear "winch" and not a hydraulic motor. So its just a hydraulic cylinder with a length of wire doubled up between a few pulleys inside the boom.

Still could be internally bypassing the cylinder rod but far less likely than internal bypassing in a hydraulic motor in a drum winch setup.

Quote:

Originally Posted by Bmarler

Just thought I’d mention, you’re on the right track doing the spool valve first, but it could also be the hydraulic motor at the winch itself bypassing internally. Rebuild for that shouldn’t be too tough either. Surprising there’s no fail safe mechanical brake on it.

Bmarler · 09-30-2023, 02:00 PM

Quote:

Originally Posted by bkcorwin

The es1000 uses a linear "winch" and not a hydraulic motor. So its just a hydraulic cylinder with a length of wire doubled up between a few pulleys inside the boom.

Still could be internally bypassing the cylinder rod but far less likely than internal bypassing in a hydraulic motor in a drum winch setup.

Ahh, I see. I’ve had many a hydraulic cylinder bypass internally. I’d put it at 50/50 between the cartridge valve and the piston seals. What’s the system pressure look like on those?

bkcorwin · 09-30-2023, 02:19 PM

Quote:

Originally Posted by Bmarler

Ahh, I see. I’ve had many a hydraulic cylinder bypass internally. I’d put it at 50/50 between the cartridge valve and the piston seals. What’s the system pressure look like on those?

Always a possibility for sure. Hopefully not, spools a heck of a lot easier to fix!

Wdeertz · 09-30-2023, 04:13 PM

Quote:

Originally Posted by Bmarler

Ahh, I see. I’ve had many a hydraulic cylinder bypass internally. I’d put it at 50/50 between the cartridge valve and the piston seals. What’s the system pressure look like on those?

Not sure what the pressure is as there's no gauge on the system. I've been trying to get the part # for the seal kits from Steelhead but their parts person has been slow. I've determined that the valve is a Bosch Rexroth Part #R932004158 or R932009304 (V4DS-3B) but haven't been able to find a source for these in the US. A google search turns up a few supplies in Europe and the Bosch online shop in the US doesn't show this part. Anyone have a source in the US for getting seal kits for these valves?

I also hope its the cartridge valve as that's much easier to fix. If it were the piston seals wouldn't I see fluid leaking? I've checked and haven't located any fluid leaks.

Bmarler · 09-30-2023, 07:55 PM

I’d look in your area for an industrial hydraulics supply house in your area. Take the valve with you. They should be able to match up the o rings, no need to replace the split backers unless they’re distorted.
I bet those are standard numbered o rings, or the metric equivalents.
Once you know the size, buy them in little 10 packs from your hydraulics shop.
Regarding the cylinder, if there’s bypassing happening at the piston, there won’t be any oil leaking to the exterior. It’s just oil slipping by the piston allowing it to move.
For now we’ll keep our fingers crossed that it’s the valve.

Wdeertz · 10-03-2023, 04:05 PM

After spending the last few days trying to locate a supplier for new seal kits I’m taking a new tack after speaking with the steelhead support. He was 99.9% sure it wasn’t the directional valve. He has me replacing the counter balance valve as a first step. He said if that doesn’t solve the issue I’ll need to replace the piston. Let’s hope the counter balance valve fixes my issue.

As a side note, the Rexroth directional valves have a 6 month lead time with a minimum order of 5 ��.

bkcorwin · 10-03-2023, 04:09 PM

So a leaking counterbalance valve could definitely do it. The dumb part is that the presence of and location of any counterbalance valves aren't shown in the diagram.

It would be stupid not to have them, but it wasn't on the diagram so I figured maybe they didn't have them?

Wdeertz · 10-03-2023, 04:18 PM

Quote:

Originally Posted by bkcorwin

So a leaking counterbalance valve could definitely do it. The dumb part is that the presence of and location of any counterbalance valves aren't shown in the diagram.

It would be stupid not to have them, but it wasn't on the diagram so I figured maybe they didn't have them?

Not sure which diagram you are referring. I wish Steelhead would make more diagrams available on their website. I obtained the attached diagram from their parts person and it shows the counter balance valve.