Hydraulic lift whining

[Brockport Bill 1,737]

have a 1983 WH C175h -- just replaced the 2 short hoses from master valve unit to the lift cylinder by the left foot rest  -- also removed shaft inside the master valve and replaced the two O rings -- what is the whining noise when operating the lift -- is it when the lift gets to its end range? Noise existed before and after repair project --- What causes it -- is it an issue? thanks, Bill

[ebinmaine 68,749]

@kpinnc.  I think? Mentioned that may be an air flow internally?

 

Any chance of getting a video so we can see and hear it?

[kpinnc 12,751]

The newer valves definitely squeal at both ends of the travel. 

 

But yes as far as I can tell it's hard to get the air out so it operates quietly otherwise. I have one that squealed something awful for a long time. 

[Handy Don 12,580]

If the squeal is at low-ish volume while the cylinder is moving, not to worry that is the fluid running through the valve and vibrating. If it is loud when the cylinder reaches its end of travel in either direction, it is the pressure relief valve making sure the pump is not being overloaded.

 

[Brockport Bill 1,737]

wh c175 hydraulic video.htm

 

 

not sure if video uploaded ??????????

[cleat 6,602]

6 hours ago, Brockport Bill said:

wh c175 hydraulic video.htm 1.59 MB · 2 downloads

 

 

not sure if video uploaded ??????????

It won't play for me.

[Brockport Bill 1,737]

[Red-Bovine 322]

I think it is normal. You are at the end of the stroke when it whines causing the relief valve to by pass.

[kpinnc 12,751]

I have one that behaves exactly that way. It has gotten better over time so I have to assume it is just prone to hold a bubble or something similar. 

[Brockport Bill 1,737]

3 minutes ago, kpinnc said:

I have one that behaves exactly that way. It has gotten better over time so I have to assume it is just prone to hold a bubble or something similar. 

 

8 minutes ago, Red-Bovine said:

I think it is normal. You are at the end of the stroke when it whines causing the relief valve to by pass.

i have wondered how the air escapes -- obviously, when i replaced two hoses they are empty of fluid and have air in them, including the master valve unit itself having air trapped after i took that apart )  -- thus meaning its now a closed system with air trapped -- its not as if there is a way to bleed the air - - soooooo, when and how, and if ever, would air escape -- or is it in the system "forever" ?? Thanks for insights -- Bill

[ebinmaine 68,749]

Some of the air works its way by hydraulic force down to the transmission case where it is dispersed.

 

 

[cleat 6,602]

18 minutes ago, Brockport Bill said:

 

i have wondered how the air escapes -- obviously, when i replaced two hoses they are empty of fluid and have air in them, including the master valve unit itself having air trapped after i took that apart )  -- thus meaning its now a closed system with air trapped -- its not as if there is a way to bleed the air - - soooooo, when and how, and if ever, would air escape -- or is it in the system "forever" ?? Thanks for insights -- Bill

 

There is constant hydraulic oil flow through the valve inlet and outlet ports then out to the filter and lastly into the rear axle housing.

That will get all air out of the long lines and part of the valve.

 

Running the cylinder in and out a few times fill force air up into the valve where it will then be quickly pushed trough to the filter and on to the axle housing.

 

All air should be quickly purged out.

 

Sound in the video is just the relief valve and is totally normal.

Actually, if the relief valve made no sound I would be worried that it was not functioning properly.

 

[Brockport Bill 1,737]

terrific explaination -- many thanks -- Bill

[Handy Don 12,580]

4 hours ago, cleat said:

 

There is constant hydraulic oil flow through the valve inlet and outlet ports then out to the filter and lastly into the rear axle housing.

That will get all air out of the long lines and part of the valve.

 

Running the cylinder in and out a few times fill force air up into the valve where it will then be quickly pushed trough to the filter and on to the axle housing.

 

All air should be quickly purged out.

 

Sound in the video is just the relief valve and is totally normal.

Actually, if the relief valve made no sound I would be worried that it was not functioning properly.

 

Air purged through the hydro system to the “tank” (the transaxle sump) exits through the hollow stem of the dipstick handle. That is the vent in the system.

As noted above, there is a constant flow of fluid through the pump and valve and through the cylinder when you activate the lever: faster when there is no load being lifted; slower when there is.The little squeak at the very start and finish, before the relief valve opens, is the vibration of the fluid being forced though the tiny opening. Kinda like whistling with air through your lips.

[kpinnc 12,751]

13 hours ago, cleat said:

Actually, if the relief valve made no sound I would be worried that it was not functioning properly.

 

I agree but the newer valve design used on the Classic series tends to squeal far more than the older valves. 

 

I'm also wondering if the travel of the actual engagement lever adds to the noise. (Possibly not opening fully due to the lever range not fully opening the valve) Point being- on two 520-H machines I've owned with the levers by the steering wheel, the only squeak came at either cylinder stop. My 523 with the same style valve (different engagement lever) squeals like a pig over the full range of cylinder movement. 

 

I think the newer Eaton charge pumps had much more volume than the older Sundstrands. As such, the cylinder moves much faster. I'm wondering if using an older style spool valve with a newer hydro would behave any different?

Edited Saturday at 05:17 AM by kpinnc

[Handy Don 12,580]

On 1/4/2025 at 12:15 AM, kpinnc said:

I think the newer Eaton charge pumps had much more volume than the older Sundstrands. As such, the cylinder moves much faster. I'm wondering if using an older style spool valve with a newer hydro would behave any different?

Can’t comment on this as I haven’t seen the specs for volumes. 

To be clear, the pressure relief valve for the Eatons is directly integrated into the control valve; on the Sunstrands, it is integrated into pump body.

Also, note that different models’ mid-tractor cylinders are different--as far as I’ve seen, they are all the same diameter, but vary in the length of the throw. Two that I picked up as spares are 4.5 and 3.25”-- the short throw being ~20% less than the long one so that would be felt as quicker action given similar pump pressure/volume. Shorter throw versions had shorter rock shaft arms to compensate so the lifted height would be the same.

Edited Sunday at 07:31 PM by Handy Don

[Bill D 1,992]

I have one Eaton that takes a minute or two before it starts working, especially when cold.  Once it starts working the pump has a noticable whine when running and the lift is not being activated.  Is this normal for some units?  It's an 1983 model Eaton 1100 with unknown hours in a GT1800.  My 94 416H is nearly silent.

[kpinnc 12,751]

4 hours ago, Handy Don said:

To be clear, the pressure relief valve for the Eatons is directly integrated into the control valve; on the Sunstrands, it is integrated into pump body.

 

 

Good point. Eatons use a simple coaxial charge pump, no internal relief. 

[johnnymag3 2,531]

It means let go of the lever....its done ......travel is complete !!!    

[kpinnc 12,751]

On 1/6/2025 at 6:11 AM, johnnymag3 said:

It means let go of the lever....its done ......travel is complete !!!

 

Mine squeaks full travel. Not as bad as it was before, but it's there. 

[Handy Don 12,580]

47 minutes ago, kpinnc said:

 

Mine squeaks full travel. Not as bad as it was before, but it's there. 

So much depends on the shape and size of the fluid passageways. Could it be possible that your control linkage isn’t fully opening the valve? Ours squeal all the time if we try to feather the control.

[bds1984 1,452]

On 1/5/2025 at 3:41 PM, Bill D said:

I have one Eaton that takes a minute or two before it starts working, especially when cold.  Once it starts working the pump has a noticable whine when running and the lift is not being activated.  Is this normal for some units?  It's an 1983 model Eaton 1100 with unknown hours in a GT1800.  My 94 416H is nearly silent.

 

That is normal.  My 1988-ish 520 has always behaved like that.  Many on here will tell you to just allow the machine to run a few minutes before putting it to work.  Anything that I've owned that is hydraulic is a bit slow when it is cold but works just fine after warming up for a bit, Wheel Horses are no exception.  

[kpinnc 12,751]

1 hour ago, Handy Don said:

So much depends on the shape and size of the fluid passageways. Could it be possible that your control linkage isn’t fully opening the valve? Ours squeal all the time if we try to feather the control.

 

Exactly my thoughts as well. This particular machine is a late 80s setup where the lift handle mirrors the PTO handle on the opposite side. It's possible the handle meets the stop before the valve does. 

 

 

[cleat 6,602]

20 minutes ago, kpinnc said:

 

Exactly my thoughts as well. This particular machine is a late 80s setup where the lift handle mirrors the PTO handle on the opposite side. It's possible the handle meets the stop before the valve does. 

 

 

Some of my 520's have that configuration.  That is my personal favorite. 

No issue with the valve with these.

I think the control under the steering wheel would be the most likely to have the valve not work fully if not adjusted properly.