Ford 6600 FEL slow to lift

cwmah

New User
Hi all,

Recently purchased a Ford 6600 tractor with an old front-end loader in Australia. The previous owner didn't do any maintenance & the old girl had been sitting for some years. I changed all of the fluids & filters as most fluids were very low/dirty.

The hydraulic selector valve was missing the piece directly inside the plastic knob which I sourced a secondhand one & fitted. It appears to work fine now, but the black knob was missing for who knows how long.

Unfortunately, the front end loader was very slow to raise & required the engine to be revved up. The tilt rams work fine & the loader drops quickly. The loader picks up a hay 5x4 hay roll with little change, maybe requiring a few more revs. The hydraulics were being fed from the single rear remote & then dumping back into the top of the transmission casing. The hydraulic lines to the FEL had a variety of homemade fittings, different size hoses, leaks & quick couplers. I have since re-plumbed the entire system with an open centre spool valve & supply coming from the forward-facing auxiliary services jack tapping point (right hand port under single spool valve) requiring the auxiliary service control knob pulled fully out to switch from the 3PL.

The FEL still goes up slowly, no real change in speed - Just a big bill for fittings $$$.

I've played with the hydraulic settings: 3PL at different heights, changing the position of the draft controller lever, adjusting the flow control knob/valve, etc.

I did consider that there might have been an internal strainer on the inlet of the pump, however the inlet appears to come from the external filter assembly with no screen. The O-ring s don t look to be in great shape so I will try reassembling with new O-rings. There was no gasket, just some black sealant. This makes me think the pump has been off in the past, perhaps due to the same problem.

I have been searching through a lot of threads & forums looking for potential sources to my problem. Some have said the pump, others mentioned leaking valves. Is there a list of checks I should work through to eliminate potential issues? Do I have the supply for the FEL coming from the right point?

Any help would be greatly appreciated!

Cheers
 

Photo of current set up
mvphoto52845.jpg
 
Hi Cwmah

Have had several Fords over the years and still got a 5000. I basically follow what you are doing. Neighbours years ago had a 6600 with a level lift challenge loader on it I borrowed it to lift some implements before we had a loader. It worked quickly. It is not in the same league as an industrial
loader with a front mount pump. My suggestion would be to get a gauge and check the performance of the pump. I can't give you the pressure it should develop but with the age of the tractor it could be tired also with the lack of maintenance by the previous owner. Good to see another Aussie
on here!
 


It could be a restriction. Fluid rushing through an obstruction will make noise. Try holding the valve open with a bungee while you listen at points where there are fittings that are possibly restricting the flow. You may find a quick easy fix.
 
How slow is slow? Tractor has less than 10gpm of flow so depending on the size of the loader cylinders slow maybe normal....
 

thanks Matt. I've got the shop manual which details some of those checks. I will have to get a gauge & have a play.

Cheers!
 

Thanks Showcrop,

I'll give that a try, all the lines to the loader are brand new so dont think it will be there. There could be an internal restriction although that will be harder to find. I'll keep looking!
 

Thanks Showcrop,

I'll give that a try, all the lines to the loader are brand new so dont think it will be there. There could be an internal restriction although that will be harder to find. I'll keep looking!
 


chevytaHOE5674,

I get what your saying. How do i determine how big my ram cylinders are? is it the same size as the chrome shaft? If i get that size & work out volume, is it as simple as working out how long to move that volume?
 

thanks Destroked 450,

I played with this control when i first got the tractor, it didn't seem to make a difference in or out. I tried to turn it again the other day, but it seems quite hard to turn. Could that be the problem?
 
(quoted from post at 06:08:16 04/19/20)

chevytaHOE5674,

I get what your saying. How do i determine how big my ram cylinders are? is it the same size as the chrome shaft? If i get that size & work out volume, is it as simple as working out how long to move that volume?

No, the rod is usually narrower than the inside diameter of the cylinder. Measure the outer diameter of the cylinder housing and then subtract for the thickness of the two outer walls, which are likely somewhere around 3/8" to 1/4" each, so use 3/8" if you don't know for sure, you'll still be close. Then divide that total in half to get the internal radius. Then measure the length of the stroke and plug the radius and stroke into the formula to get the total volume that you have to move:

Volume = pi x (radius squared) times stroke.

Then , since you have two lift cylinders multiply that by 2 to get the total volume that you have to move. If your measurements were all in inches then the final number will be in cubic inches and you'll have to convert that to gallons.

Keep in mind that the pump is rated for that 10 gpm at a particular pressure and with no restrictions to the flow in terms of no part of the path of flow being too narrow. If you hear any kind of whine then there is a restriction somewhere and you're not getting anywhere near the rated flow from the pump.

What is the pressure and flow rating of your new control valve?

My '73 4000's pump is rated at only 5.3 gpm and the lift cylinders on the loader are 2.5" bore and 16" stroke, so that would work out to:

volume = pi x (1.25 x1.25) x 16 = 78.5 cubic inches

Double that to 157 total cubic inches of volume for both cylinders combined, which is approximately 2/3 of a gallon.

So the pump, which is rated at 5.3 gallons per minute should be able to move a gallon in about 11 seconds, so 2/3 of that would be around 7.5 seconds. In reality it takes around 9 seconds to lift the arms from full down to full up, so that is not too bad with only 17% time loss due to inefficiencies of restrictions to flow and loss to heat.

Your tractor's pump has more rated flow than mine, but the cylinders are probably larger, so your numbers may vary, but if you are getting any times lower than 10 seconds from full down to full up then I would bet that is probably close to the best you are going to do.
 

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