# Vermeer 2800 rake surging



## j_maciejewski (Mar 5, 2010)

I have a Vermeer 2800 twin rake. Whenever it runs, the hydraulic motors that run each basket will surge, every few seconds or so. There is a hydraulic block where the hydraulic lines run thru, and there is a relief valve installed into it as well. When it is surging, you can hear the relief bypassing some oil. I am running this rake with a Magnum 210, so it should be putting out enough flow. I am assuming It has something to do with the pressure and flow compensation built into the tractor, but I’m not sure. This is the second tractor we have had the rake on, and the same results every time. Any help would be appreciated.


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## Tx Jim (Jun 30, 2014)

Welcome to HT

It's been many yrs since I owned a Vermeer R23. IIRC surging of baskets can be caused from rake relief valve not properly seating. I will recommend inspecting rake relief valve for foreign material.

I altered my R23 from tractor hyd powered to pto pump powered utilizing rake tongue as the oil reservoir pulling rake with a Ford 3000


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## Jimmy Bartlett (Aug 17, 2015)

What happens if you lower the flow setting on tractor scv?


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## Gearclash (Nov 25, 2010)

I am assuming that the 2800 uses the same type of system as the 2300. Oil flow from the tractor for the basket drive first flows through a priority valve. On the R23/2300 the priority valve sends 8 gpm on to the baskets and returns the rest to the tractor. After the priority valve there may be a manually adjustable flow control valve that allows the operator to slow baskets down below the 8 gpm speed. Then at the rear of the rake there is a relief valve that limits pressure to 2000 psi in the forward direction and 50 psi in the reverse direction. Its purpose is to provide overload protection in the forward direction, to prevent reverse rotation of the baskets, and to allow the baskets to spin down after the scv on the tractor is shut off. When we had an R23 it would tend to surge a little, and it would also stall rather easily. I shimmed the relief on high side and the easy stalling went away. The R2300 we have now doesn't surge, but we run it on an older tractor with an open center system. I wouldn't be at all surprised that the surging could be from running the rake on a PFC system. I would try turning the flow control on the tractor down until you see the baskets slow down, then turn the flow up slightly.


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## E220 (Feb 10, 2016)

The problem is that your rake only needs 8GPM and your tractor is set to send as much as possible which is probably 30+. The flow control on the rake and the pressure-flow compensation on the tractor fight for a balance and cause the surging. You have 3 options, but only one is a true fix.

1. If your tractor has flow controls, slow them down until the baskets slow down, then turn it back up a bit.

2. Buy an old IH open-center tractor.

3. Ask your dealer for a kit...AK01607. This disables the priority valve on the rake and only uses the orifice for flow control. This is a pricey kit but fixes the problem.


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## j_maciejewski (Mar 5, 2010)

Thanks everyone for the input. I did get it figured out. Vermeer makes a kit that replaces the relief valve and the assembly. The replacement will work for tractors with pressure and flow compensated pumps. Actually, the new rakes from the factory have this kit already installed. Good info for anyone else having this problem.


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## Gearclash (Nov 25, 2010)

If all you rake is dry hay I would try slowing down the flow on the tractor before spending any $$$$. Those rakes turn the baskets plenty fast for raking dry hay, there would be no harm in running the baskets at s slightly reduced speed. Wet hay could be a different story as wet hay takes way more rake power and is harder to pick up clean.


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## j_maciejewski (Mar 5, 2010)

It is more than just a little surge. The baskets will lose a third of its speed. Plus it is working the tractor pump needlessly. And there is an increase in oil temp from constantly shoving oil thru the relief. I’m a big believer that machines should run the way they were designed. If it isn’t right, make it right. Got too much to do to be half broke down.


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## stack em up (Mar 7, 2013)

Glad you got it fixed.


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## Gearclash (Nov 25, 2010)

No matter what you do there will be some heat . . . it's a continuous hydraulic load.


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## skyrydr2 (Oct 25, 2015)

For proper hydraulic motor control of 2 motors it should have a flow divider NOT a priority valve? That's a heat source in it self. Proper flow through system is critical for heat management and ramajaming 30gpm to a 8 gpm system is gonna cause issues. That Case should have a flow adjustable close centered system, this is one of the best systems to use,as you can feed it only what it needs by compensating pump volume. This should keep oil temps way down.


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## E220 (Feb 10, 2016)

Gearclash said:


> No matter what you do there will be some heat . . . it's a continuous hydraulic load.


That's true but this is similar to running an open-center system on a closed-center tractor. 8GPM at 1800PSI is a very small load. If the pump is generating 20-30GPM, the extra oil flow is energy that will need to be released somewhere and that energy turns into heat. (I'm not an engineer, so I'm just repeating what I've heard.)

If the tractor has flow controls, you can make the rake work fairly well, but it still will stall more quickly than it should.


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## Gearclash (Nov 25, 2010)

skyrydr2 said:


> For proper hydraulic motor control of 2 motors it should have a flow divider NOT a priority valve? That's a heat source in it self. Proper flow through system is critical for heat management and ramajaming 30gpm to a 8 gpm system is gonna cause issues. That Case should have a flow adjustable close centered system, this is one of the best systems to use,as you can feed it only what it needs by compensating pump volume. This should keep oil temps way down.


The motors on these rakes are plumbed in series. The priority valve simply sends 8 gpm to the motors and returns the rest to the tractor.


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## skyrydr2 (Oct 25, 2015)

Gearclash said:


> The motors on these rakes are plumbed in series. The priority valve simply sends 8 gpm to the motors and returns the rest to the tractor.


 In series? So oil flows into one then out of that unit into the other? That is a series( they should be parallel) So if 1 stops they both stop? Hmmm that is just not how it should be it should have pressure lines to each motor from flow divider and both motors should have returns to tank with out running through a valve body or they would need very low pressure input or they would blow shaft seals with out case drains


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## skyrydr2 (Oct 25, 2015)

I have seen some pretty silly hydraulic circuits in my day that just did not work correctly (cat skidders come fresh to mind) and it seems the simpler they are the better they work!


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## Gearclash (Nov 25, 2010)

They are in series. It works fine and is the simplest way to do it. Otherwise they would need a flow divider in addition to everything else. The motors have no case drain, I’m sure they wanted to avoid a motor that required a case drain to keep their product plug and play ready with any tractor


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## glasswrongsize (Sep 15, 2015)

putting my sub-2 cents worth. If they were in parallel, one motor could spin way faster than the other if loads are not same; the one with less load would be path of least resistance for pressure; in series, same GPM must flow over each pump on its way to being returned.


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## j_maciejewski (Mar 5, 2010)

Got the kit and put it on. It works perfect. No surge. Can dial the pump down to give it just what it needs. If anyone else has this problem, it can be fixed for under $800.


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## cannonball (Jun 23, 2012)

Gearclash said:


> They are in series. It works fine and is the simplest way to do it. Otherwise they would need a flow divider in addition to everything else. The motors have no case drain, I'm sure they wanted to avoid a motor that required a case drain to keep their product plug and play ready with any tractor


The r23 had a cushion valve on them, so if you shut of flow then it would allow hydraulic motors to keep spinning and not have hyd shock


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## Gearclash (Nov 25, 2010)

cannonball said:


> The r23 had a cushion valve on them, so if you shut of flow then it would allow hydraulic motors to keep spinning and not have hyd shock


Correct. Technically all it is is a 50psi relief valve on the return side of the motor flow. It is in the same block as the 1800 psi relief valve on the rear of the rake frame.


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## skyrydr2 (Oct 25, 2015)

With a low flow of 8 gpm they must be gerotor type unit as they make crazy torque with minimal input . If it has a gearbox in between motor and tine rotor then it could have a multitude of different types. If you turn one side by hand does the other side turn? 
Parallel with flow divider will not allow one to turn faster than the other because flow is metered equally . They meter in both directions easily too. And have built in cross over reliefs to keep things safe allowing the motor to essentially "free wheel" when supply is cut off. 
Plumbing it in a series uses the first motor as a "rotary flow control" for the second one. Easy way to do it but not as effective as using a devoted rotary flow control. 
But it works now . Curious as to what that "kit" consisted of?


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