# hydraulic /3 point operation



## ford51 (Nov 29, 2012)

Greetings guys ,
having a bit of a problem with my ford 4000 ,there is a quicke loader on front and a large ballast weight on back linkage ,i lift up ballast weight with services button pressed in , no problem ,but when i pull services button out half or full way to use external services i,e loader ,ballast weight /rear linkage drops to ground..if i take weight of and try again linkage will stay up ,is this normal ,am i doing something wrong .confused:


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## Big_T (Dec 1, 2011)

When you pull the ASC (auxiliary service control) valve out, there is no hydraulic fluid supplied to the three point lift. ALL THREE POINT LIFTS BLEED DOWN WITH LOAD. The bleed-down rate depends on the condition of your lift system (and the weight of the load invloved). My tractor's system is very good, it can hold up a 1500 lb mower for a long time, but it will ultimately bleed down. 

To test your bleed down rate, raise the ballast weight with the ASC valve in the down position, and shut the engine off. Determine the time it takes for the lift to go down. Then raise the ballast weight again, and pull the ASC valve to the up position, kill the engine and again determine the time for the lift to go down. The times should be similar. If if goes down more quickly with the ASC in the up position, the ASC valve may also be leaking.

The simple solution to your problem is to raise the ballast weight and chain it in the up position, or simply don't use it. You can load the rear tires with fluid and get similar results. Add rear wheel weights and get even more traction. The other solution is to bypass the ASC valve and supply hydraulics to both the loader and three-point at the same time.

PS - that "quicke loader" loader is going to be very slow using your tractor's internal hydraulics. The hydraulic pump rate for a 4000 is about 5 GPM, which is less than half a normal loader's requirements for efficient operations.


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## ford51 (Nov 29, 2012)

thanks T ,it makes sense now ,pull plug no oil to back , i have had hyraulics overhauled ,seals ,filter replaced ,lift piston seal was worn away ,pressure check now raises to 2500psi and holds ,good as new . ballast weight was to heavy ,so i decided to bin it ,but to heavy to lift i cut top off with torch ,and found it was a metal box filled with 12 barrow loads of sand ,took sand out and fitted a hinged lid ,now i have a handy box on back which is also heavy enough to use loader without rear wheels coming of ground ,i did as you said and fixed rear 3 point link up by fitting a extention on drawbar which weight sits on if i use external service knob ,as well as a chain to hold it up just in case . My quickie 415 works quite quick ,i looked into pump pressure and on my 4000 it has independent pto ,so is fitted as standard with a gear type hydraulic pump which gives about 8 gpm as apposed to piston type which as you say gives 5 gpm .thanks for pointing me in right direction .great site .l


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## DanC (Oct 4, 2013)

Big T ..... Good info on the bleed down rate. My Ford 540 3 point had become slow to lift when cold then one morning no lift BUT before when I shut it off with the box up it lowered pretty slow so I will take that as a good sign. A local mechanic advised that I have a piston pump with no filter and a strainer low inside the cases near the rear end that requires removing the seat and the "head unit?" from the top of the case, a fair amount of work for my skills. He recommended draining and changing the oil first if is due (it is) and that may clear the screen. If that does not work, remove the remote pump from the engine and bring it in for inspection and rebuild if needed. If it looks good then drain/save the new oil, remove the head unit, clean the strainer, and inspect the lines for blockage. I didn't check to see if the auxiliary controls for tilting the box still work but will check that when I warm it up to drain the oil. Thanks


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## Big_T (Dec 1, 2011)

Howdy DanC,

Welcome to the Ford/New Holland Tractor Forum. I've attached a diagram of an engine-mounted piston pump. Mounted on the left rear of the engine, driven by a gear on the camshaft. Note that the pump has a check plug - item #20. You can loosen this plug (don't remove it completely - makes a mess) to see if the pump is primed and also if the hydraulic fluid from the pump has air in it. You can also install a 3000 psi pressure gauge in this port to check your hydraulic pump output pressure. 


The suction line (larger line on pump - about 1 inch diameter) has an o-ring seal on each end that may be leaking, allowing air to be sucked into the system. Your pump will not do well when it's sucking air into the hydraulic fluid. The lower end of the suction is attached to a suction screen low on the right side of the rear hydraulic reservoir.

After you drain the hydraulic fluid, remove the suction line and blow compressed air back through the suction screen to clear it. Install new o-rings on the suction line and re-install it. Try to flush the reservoir bottom with clean hydraulic fluid to get any crud out of the reservoir. 

Fill the reservoir with new Universal Hydraulic Fluid (UTF) meeting Ford oil spec 134D. You can get UTF at Tractor Supply Stores, auto parts stores, Wal-Mart, etc. 

Your tractor should also have an external "spin-on" hydraulic filter. Change the filter when you change fluid. 

Hope this all makes sense to you. If not, let us know.


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## DanC (Oct 4, 2013)

Thanks Big T ..... that is excellent info. Blowing out the screen will save me a ton of work. I have the fluid so I can drain today and blow out the screen. I may get lucky and match the o rings at the local Auto Parts store today, the parts list you linked has the o ring specs. I should be able to borrow a 3,000 psi gauge from our mechanic at work if I still have a problem after that. That diagram is much easier to follow than the ones in the Ford manual. Thanks for taking the time.

FYI the dealer says there is no filter on this model with the piston pump and I don't see one, it would have to be internal if there is one.


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## DanC (Oct 4, 2013)

Well I pulled the pump plug and the fluid looked dirty but I didn't see any air bubbles. Started it up with the plug loose and it dripped but did not spay. Drained the oil and got about 36 quarts. My book says 33.9 or 48.3 with independent PTO? I have a PTO but not sure if it's "independent". For my model they list Transmission PTO or Independent PTO but I don't know which I have? I either had too much oil or not enough


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## Big_T (Dec 1, 2011)

Find the model number, and I can tell you what type PTO your tractor originally came with. There should be a sticker under the hood with model number, serial number, and manufacturing code. If the sticker is gone, you can find these same numbers stamped into the metal on the flat spot just above and behind the starter.

Does your tractor have a loader?


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## DanC (Oct 4, 2013)

Big T ...... yes it has a loader with a separate pump at the front of the engine. The number stamped on the engine block behind the starter is *C622886*. The sticker label is not readable but I wrote down some numbers on the manual when it was: MOD# DW312K, TRANS # 9H30B. I have some other numbers too if it helps.

Thanks again


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## Big_T (Dec 1, 2011)

Model DW312K:
DW3 = model 540 
1 = diesel engine
2 = Trans PTO, 540 RPM
K = 6x4 manual reversing trans

Manufacturing Code 9H30B:
Year = 9 = 1979
Date = H30 = August 30
Shift = B = day shift

Serial number C622886 is consistent with August 1979 manufacture.
C = Made in USA

PS - I added a parts diagram of your rear differential center housing to illustrate one thing. The fluid level check plug - small square-headed pipe plug. See item #6, just in case you are not aware of this check plug. Pour UTF into the filler hole on top of the center housing till it comes out this fluid level check port. Do not take out the slotted head screw right near it (it supports brackets internally).


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## DanC (Oct 4, 2013)

Thanks again Big T. So per my book I should have 33.9 quarts and maybe some extra for the 3 accessory box cylinders, angle/tilt/ripper. Going out now to see if I can clean the screen and rinse with clean fluid. Added a photo, the sticker label got torched from an electrical fire a couple years ago.


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## DanC (Oct 4, 2013)

Big T. More photos. Removed the step and found the small pressure supply line had an O Ring fitting but the larger suction line was cast as part of the manifold. There was an aluminum 1 3/16 nut that I was really wanting to be a filter or screen but it looks like it may be for flow control? It was pretty clean. Not sure what's next.


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## Big_T (Dec 1, 2011)

That piece appears to be a pressure relief valve. See the pump parts diagram. Take care not to change the setting of this valve. 

The large suction line should pull out of the manifold. It is pushed into it with o-ring seal. It may be painted to appear as one piece?? Have to remove any clamps that keep it from moving, including the pump connection on the other end..

OK, I went out and looked at my tractor to refresh my memory. The suction line is sandwiched between the pump and the reservoir. Rigid line. I wouldn't risk trying to force it. I had the pump off on mine fixing a leak several years ago. 

I believe you have to pull the pump to get the suction line off. When you do that the suction line is accessible on the pump end, so there's no need to pull it from the reservoir end. If you blow air back through the suction screen, make sure you have the reservoir vented (filler cap off) so you don't blow any seals internally.

For now, I would finish changing the fluid and proceed to check the hydraulic system. From your description this morning, the pump may be suspect. Put a 3000 psi pressure gauge on it and see what it is putting out.


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## DanC (Oct 4, 2013)

Thanks again Big T ...... I didn't see any adjustment on the Aluminum valve and just cleaned it and re-installed. I pulled the pump and was able to blow some air back into the suction line at the pump end. Got some more fluid in the drain pan and was not able to make any pressure so I think it is clear. Since I have the pump off I am going to take it in for inspection and a rebuild quote so I know where I am at before I refill the fluid and install the pump


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## DanC (Oct 4, 2013)

Big T ..... Update ...... I called the Tractor Dealer yesterday again, They have had the pump a week. They removed the pump "head" and found a broken pin, must be # 41 on your diagram BUT they are having trouble finding the part. I think that may mean that since they are no longer a Ford Dealer they are having trouble "buying" the part. Any way the good news is that the problem is located and should not be too expensive.

My question .... I plan do pour some fresh oil down the pump suction line before I put the drain plug in to see if I can flush the screen a little more then filler back up with new oil. Do I need to try and fill the suction line or prime the pump? The test plug is on the bottom but I should be able to fill the pump before install but that will get a little messy. Thanks again


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