Ford 555B Boom and Stick hydraulics won't work simultaneously. Is this normal?

[UrbannGuerilla]

We just got a Ford 555B TLB about a week ago. This is our first backhoe. If I use more than one hydraulic control at a time, they don't work together. For example, if I try to lift the boom and crowd the stick at the same time, only the stick crowds, when the stick has reached its stop (or you release the crowd lever), then the boom works. they don't both operate at a normal or fast rate together (This is under no load, in open air). However, if I crowd the stick and lift the boom slowly, with very slight control pressure, they both will operate together at the same time. Is this normal? Or is there an issue? I have read a lot about backhoe operation prior to getting this machine, and everything I've read, and every video I have watched, always say that you need to eventually learn to do all 3 motions (bucket, stick, boom) at the same time for smooth efficient operation... so now we got this backhoe, and I can't use all 3 of them together at one time.... and I can't practice using all 3 together. You have to move one, then move the other unless you really do it slowly, and that doesn't seem right. Can someone help me out? I have googled for 2 days now and I can't seem to locate any valuable information regarding this specific subject.

The tractor only has one small occasional hydraulic drip, but its on the left FEL hydraulic, not the backhoe. There are no leaks on the backhoe.

 

[RickB]

You need to feather the controls, do not move them all the way when trying to use multiple functions. What throttle setting are you using? Fixed displacement pumps provide flow proportional to ERPM. Also has the hydraulic system filter been changed and the suction screen been checked or cleaned? Oil level checked?

 

[TractorGuy]

Doesn't sound normal. Is this a two or four stick control?

I can rake the surface using both controls with my 575E. I set my throttle around half speed to cut down on jerkiness. I don't think mine will let me move the boom side to side as I pull back on the crowd stick. Make sure you are pulling the stick straight.


Like RickB said, you have to feather.

 

[ovrszd]

My 555A is efficient enough that I rarely fully activate any of the valves. Almost always am feathering the controls. It easily does all functions at once. I can lift boom, crowd stick, curl bucket and swing boom all at once. I only notice a slight difference in swing speed if doing multiple functions while swinging.

I agree with Rick, I'd start by making sure the pump is able to distribute it's full capacity, clean suction screen, filter, etc.

If they are all good then I'd question the efficiency of the pump. If it's a worn pump problem the slowness should be noticed regardless of combinations being used. Shouldn't only be specific to one valve function to see slowness.

If you get thru all this and confirm that it's specifically one combination that's slow then we would start suspecting a valve or possibly a cylinder.

Right now I think there are too many unanswered questions to start blaming a valve or cylinder. Set up as many test configurations as you can imagine. Remember in detail the changes you see.

These old hoes are extremely powerful and quick for their size. Mine is an extendable stick on the long boom with a 24" bucket. I put a heavy load on my pump and it always delivers.

 

[ovrszd]

Doesn't sound normal. Is this a two or four stick control?

I can rake the surface using both controls with my 575E. I set my throttle around half speed to cut down on jerkiness. I don't think mine will let me move the boom side to side as I pull back on the crowd stick. Make sure you are pulling the stick straight.


Like RickB said, you have to feather.

I forgot to mention, mine is a two stick.

 

[RickB]

I forgot to mention, mine is a two stick.

That’s an unusual configuration for an A series. But the differences are from the top of the valve spools up to the grips, the hydrulics are the same so your comments are valid.

 

[mike48130]

This is normal. The valves are stacked valves, a section for each control, and the oil flows into the first block and out the last. When you move a control to full, all flow is diverted to that function. When the function maxes out at the stop, the relief in that section (each function has a relief pressure) opens and allows oil to flow thru the rest of the block allowing the other functions to work.

Like you said, when you feather multiple controls they all work at the same time. This is because the spool is not fully closed directing the oil to only the one function so it will operate that function slower, but allow oil to flow to the others as well. This is common, and depending on the equipment the valves will be ordered so certain functions have priority over others. JLG does this on their lifts and explained in the manual as such.

So it is a balancing act of engine speed which equals oil flow and how fast you want multiple functions to work at the same time.

My 550 has the 4 lever hoe, and works this way as well.

 

[ovrszd]

That’s an unusual configuration for an A series. But the differences are from the top of the valve spools up to the grips, the hydrulics are the same so your comments are valid.

Yep. I stumbled on to this one. I prefer the two stick configuration. Although "professional" operators will say they have better control with individual sticks.

 

[Peter 315]

 

[RickB]

Yep. I stumbled on to this one. I prefer the two stick configuration. Although "professional" operators will say they have better control with individual sticks.

I ran into a potential buyer of a 655E a few months back that wanted a price on a two stick conversion kit for the E as it was a 4 stick machine. I was shocked that the kit was still available and he was shocked at the price. B series were about the last that were predominantly 4 stick and up north I had never heard of a 4 stick E.