Ford 555C boom/dipper

[Rich555C]

Hi, I'm new to the site. I did find a post related to my concern and did reply to it but the post is 4 years old and have not received a reply yet so I figured I would ask the question again. I just purchased a Ford 555C in great condition. I am having an issue with the backhoe. I can combine any movements on the hoe at idle or full throttle with full stick movements and everything works except when I was the dipper and the boom together. The boom and dipper work great when used separately. If I move the boom in and then try and move the dipper in, the boom will stop, and the dipper continues to work. If I move the dipper in and try to move the boom in, the boom does not move. I can feather both dipper and boom very lightly at the same time and both will move together. I spoke to someone locally that operated a 555 for years and he said this was not right. He could move both controls at full movement and they both worked together. He also mentioned, and it makes sense, it would take forever to dig something the way it is now. The boom and dipper are the largest cylinders on the tractor. I know the value block for the controls is a segmented design and the oil passes from one to the next. In one side and out the other. The dipper and boom are a couple of segments apart. Did anyone ever figure out what the fix was? Thanks

 

[Dman1981]

Pressure check and a flow meter

 

[K5lwq]

Definitely need to check flow rate. Your backhoe is open center design. The valve stack should have a parallel channel for excess fluid to be available for the next valve. But because the bigger cylinders you are running out of available fluid to work at full capacity. This is why when you feather the valve you can get it to work together.

Possible issues could be filter needs replaced. Also there may be a strainer on this unit that could be clogged. Not sure if it has this or not but I think it does.

Another possibility Is worn pump. But a flow test is definitely in order to start figuring out where to go next. Hope this helps and good luck.

 

[Rich555C]

Thank you for the responses. The hydraulic filter is new. The operator's manual does show an outlet screen under the outlet hose. It's supposed to be services every 1200 hours. The amount of maintenance with this tractor is huge. I'm going to take a guess and say it probably has never been cleaned. I have an operator's manual and parts book but not a service manual, but it looks like it might not be that hard to get to. After the grill is removed, I'm hoping the hydraulic cooler will tip forward out of the way to gain access to the outlet hose. I'm hoping to find a clogged screen verses a weak pump. All other hydraulic functions great.

 

[EddieWalker]

I have a 555E, so I can't say for sure on yours. Do you have a big filter inside your hydraulic tank? On mine, there is a round plate on the side of the tank that you have to remove to get to that filter. The tank has to be drained, which is why it isn't changed very often.

 

[rScotty]

I think that you should hold off on the flowmeter test equipment. They are a couple of thousand dollars, hard to hook up, and I doubt if that info is going to tell you anything new. Very few tractor dealers have a hydraulic flowmeter. Maybe some of the industrial dealers do. I've never seen one in a small shop.

A pressure gauge is a different story. Eventually you ought to geta 5000 psi glycerin- damped pressure gauge and some hardware to mount it at the main input port to the BH valve stack. Sitting there, it allows you to compare one valve against another.
Amazon has portable pressure gauge test kits with multiple fittings for under $100. Or make up your own for half that.

I have a JD310 and never did understand the hydrauics until I studied the service manual - which comes in a set of volumes and is costly but worth it. Recommend you get the original parts and service manuals. Look for used manuals on Ebay. Lots there.

rScotty

 

[rScotty]

SNIP...... The operator's manual does show an outlet screen under the outlet hose. It's supposed to be services every 1200 hours.

The amount of maintenance with this tractor is huge. I'm going to take a guess and say it probably has never been cleaned.

I hear you on huge maintenance. The recommended maintenance on a JD310 would just about take a full time maintenance mechanic. So of course it never gets done.
Ours is a 2006 model with 6000 hrs and I bet a third of the maintenance items have never been touched. It works perfectly.

I have replaced a number of rubber hoses. Always suspect the main suction hose from the sump to the hydraulic pump inlet. Inspect the ends of that hose/pipe for oil wetting which means it is sucking some air. Entrained air degrades a hydraulic system.

Your problem doesn't sound too bad. If that filter doesn't fix it, new possibility would be to look at the auxiliary valves that are associated with your dipper or boom control spool valves. The 555 hydraulics shop manual will have details.

Basically, in a backhoe control valve array, each one of the 4 to 8 control spool valves on that BH control array tends to have several smaller cans bolted to every one of those spool valves. These cans contain each spool valve's own relief valve, drop protection backflow valve, and an anti-cavitation valve for that spool valve's motion. Sometimes those features are combined, but there are stll lots of these nearly identical accessory valves sort of riding shotgun for each control valve spool.
Normally these accessory valves are poppet & spring type, and more or less rebuildable/cleanable. They sometimes get crud caught under the valve face.
If the screen doesn't do it I'd head there next.
But get a shop manual first.
rScotty

 

[Rich555C]

I have a 555E, so I can't say for sure on yours. Do you have a big filter inside your hydraulic tank? On mine, there is a round plate on the side of the tank that you have to remove to get to that filter. The tank has to be drained, which is why it isn't changed very often.

My tank does have to be drained and there is supposed to be a screen inside the inlet hose for the pump or tank outlet hose, same hose. It's right under the tank. I agree with you. It is not easy to get to like the hydraulic filter and probably has never been serviced.

 

[Rich555C]

I think that you should hold off on the flowmeter test equipment. They are a couple of thousand dollars, hard to hook up, and I doubt if that info is going to tell you anything new. Very few tractor dealers have a hydraulic flowmeter. Maybe some of the industrial dealers do. I've never seen one in a small shop.

A pressure gauge is a different story. Eventually you ought to geta 5000 psi glycerin- damped pressure gauge and some hardware to mount it at the main input port to the BH valve stack. Sitting there, it allows you to compare one valve against another.
Amazon has portable pressure gauge test kits with multiple fittings for under $100. Or make up your own for half that.

I have a JD310 and never did understand the hydrauics until I studied the service manual - which comes in a set of volumes and is costly but worth it. Recommend you get the original parts and service manuals. Look for used manuals on Ebay. Lots there.

rScotty

I bought the tractor from the original owner. It's a one owner tractor and I do have the original operator's manual and parts book. I did notice last night that there are quite a few used service manuals online for sale.

I like the idea of building a pressure gauge set up. That will be my last resort if I do not find anything with the screen.

I did dig a crawl space once with a JD 310D extend a hoe. It was a nice tractor and I remember the boom and dipper working simultaneously without any issues.

 

[Rich555C]

Those are all good points. You mentioned oil wetting. Do you basically mean oil leaks around the suction hose? I'm thinking a suction hose leak while running would cause cavitation of the oil and degrade it fast. And then possibly leak while not running. I can glance at mine somewhat through the grill and see a lot of residual dirt and oil mixed. It also could be from spillage from adding to the tank.

The value block assembly is not that bad to access, and I can see those small can shaped covers. Some are on the top and some are on the bottom of the value block. I'll have to look at my carefully. I can see the ones on the bottom collecting dirt over the years and possibly sticking or dirt holding them open causing a pressure loss. I figured they were covering some sort of pressure relief value. I'll check those after the screen.

 

[Rich555C]

Today I drained the hydraulic tank and removed the inlet hose. There was no screen or snap ring. Someone removed it and never installed it. Since I was thar far I removed the entire inlet hose to the pump to make sure nothing was stuck inside it. Nothing was. After putting everything back together I went to the backhoe value block. The boom hoses look to have been replaced not that long ago. The boom valve had the small round can looking cap on the top of it. I removed it. I'm almost sure it is an adjustable pressure relief valve. I took it apart, cleaned and reassembled it the same way it was. It was clean on the inside. After reinstalling it the hoe still works the same way. There is something else on the lower side of the boom valve. I'm not sure what it is. After it was together I had some more time to work all the functions. I now realize that when working the dipper nothing else works at the same time. No swing left to right, no bucket curl, and no stabilizers. When working the boom everything else will work with it but everything seems slow to move.

 

[K5lwq]

It is a flow issue. Take a clean 5 gal bucket and mark it at 2 gallon mark. Then take a hose from a cylinder that is working and time how many seconds to get to the 2 gallon mark. Then repeat with a hose from a cylinder that does not work so well and compare numbers. Then do the math to determine GPM. Tractor data list flow at 31GPM.

 

[Rich555C]

It is a flow issue. Take a clean 5 gal bucket and mark it at 2 gallon mark. Then take a hose from a cylinder that is working and time how many seconds to get to the 2 gallon mark. Then repeat with a hose from a cylinder that does not work so well and compare numbers. Then do the math to determine GPM. Tractor data list flow at 31GPM.

At what RPM should I perform this test at? Since it is a flow issue does it matter what cylinder, I check? If I tested the boom and dipper, could they be within spec since my issue is a combination of two or more or would they still show low flow tested individually?

 

[K5lwq]

At what RPM should I perform this test at? Since it is a flow issue does it matter what cylinder, I check? If I tested the boom and dipper, could they be within spec since my issue is a combination of two or more or would they still show low flow tested individually?

About 2000 RPM should be sufficient. I like test from multiple spots. Also for over all pump flow you could do it from the pump. Although that is tougher without help.

 

[Rich555C]

About 2000 RPM should be sufficient. I like test from multiple spots. Also for over all pump flow you could do it from the pump. Although that is tougher without help.

Testing from the pump would be hard to do. If I have a flow problem when using a combination of functions, would testing individual cylinders probably still show low? Each function by itself seems ok but could be slow and I just do not know it be a new owner. I have noticed lowering the stabilizers, one by itself seems ok but both together are very slow.

 

[rScotty]

SNIP.......I now realize that when working the dipper nothing else works at the same time. No swing left to right, no bucket curl, and no stabilizers. When working the boom everything else will work with it but everything seems slow to move.

Great! It sounds like you are beginning to pin it down. You may want to skip the flow testing. It is interesting, but I can't see how it leads to a solution.

My thought is that without the screen to filter out the inevitable bits of crud that any system has, I'm more convinced that the problem is one of the auxiliary poppet valves associated with the dipper spool valve is being held open. That open valve is diverting the extra flow that would normally be available to the other cylinders. Instead of being available to power other motions, the extra flow is going directly to the return line anytime you use the dipper.

Each major two-way cylinder - boom, dipper, bucket, swing cyiinder set, and thumb if you have one -
is extended or contracted by a spool valve. But because it of the way a backhoe works, each spool valve has to have two relief valves (one for extend & one for contract), plus each spool valve has to have a check valve so it keeps its position when another cylinder is working, and each spool valve has to have an anit-cavitation valve so that if the hoe's motion overpowers one of the cylinders then some reserve fluid is available to prevent cavitation in the cylinder.

That is a minimum of 4 discrete spring-loaded poppet valves per spool valve. I think you need to look at your shop manual and find all those for the dipper spool valve, take them apart and clean them. One of them is being held open and dumping your flow to the return line.

We just went through all this on another thread. It's not unique to Ford 555 hoes.

Backhoe Side to Side -- Stuck?

Thanks rScotty! Funny you mention the pushing it back, that's what I did once on a stump already, just hooked it and drove around to straigthen it out... I don't mind it being random\weird but when I'm going 10mph down a 1 lane road with 200 homes and it randomly slams to the other traffic...

www.tractorbynet.com

rScotty

 

[Rich555C]

Great! It sounds like you are beginning to pin it down. You may want to skip the flow testing. It is interesting, but I can't see how it leads to a solution.

My thought is that without the screen to filter out the inevitable bits of crud that any system has, I'm more convinced that the problem is one of the auxiliary poppet valves associated with the dipper spool valve is being held open. That open valve is diverting the extra flow that would normally be available to the other cylinders. Instead of being available to power other motions, the extra flow is going directly to the return line anytime you use the dipper.

Each major two-way cylinder - boom, dipper, bucket, swing cyiinder set, and thumb if you have one -
is extended or contracted by a spool valve. But because it of the way a backhoe works, each spool valve has to have two relief valves (one for extend & one for contract), plus each spool valve has to have a check valve so it keeps its position when another cylinder is working, and each spool valve has to have an anit-cavitation valve so that if the hoe's motion overpowers one of the cylinders then some reserve fluid is available to prevent cavitation in the cylinder.

That is a minimum of 4 discrete spring-loaded poppet valves per spool valve. I think you need to look at your shop manual and find all those for the dipper spool valve, take them apart and clean them. One of them is being held open and dumping your flow to the return line.

We just went through all this on another thread. It's not unique to Ford 555 hoes.

Backhoe Side to Side -- Stuck?

Thanks rScotty! Funny you mention the pushing it back, that's what I did once on a stump already, just hooked it and drove around to straigthen it out... I don't mind it being random\weird but when I'm going 10mph down a 1 lane road with 200 homes and it randomly slams to the other traffic...

www.tractorbynet.com

rScotty

Thanks Scotty. That sound like my issue exactly. I do not have a shop manual yet so I'm kind of guessing at this point. I did take off a valve yesterday that was on the top side of the dipper spool valve. I think it was an adjustable pressure relief valve. Under the cap was a jam nut, adjustable straight slotted shaft/pin, spring and a valve in the bottom. On the bottom of the spool valve is a larger type of valve. I'm thinking this is the one you're referring to. I would think all these poppet valves have to be together and right next to the related spool valve. One thing I think is not the issue but want to mention. I noticed that I have one 90 degree fitting that has a slight bend to it. It's on the hose that would pull the dipper in. I took the hose to a hydraulic shop and was told it was not causing any restriction.

 

[Rich555C]

Well after looking at the hose routing I realized I made a mistake. The pressure relief valve I took off yesterday was for the boom and not the dipper. Today I took off some kind of valve for the dipper spool valve and took it apart. I did not see anything wrong with it. There is a part of it I cannot get apart. It's in the first picture. It's the very top left part. There is a spring and a valve inside it. It must come apart somehow. I did kind of screw up slightly. I did not realize that was a jam nut for the cap on the very top and did not count the turns when unthreading it. There is discoloration on the threads on the inside and the picture should help some putting it back together.

 

[rScotty]

Thanks Scotty. That sound like my issue exactly. I do not have a shop manual yet so I'm kind of guessing at this point. I did take off a valve yesterday that was on the top side of the dipper spool valve. I think it was an adjustable pressure relief valve. Under the cap was a jam nut, adjustable straight slotted shaft/pin, spring and a valve in the bottom. On the bottom of the spool valve is a larger type of valve. I'm thinking this is the one you're referring to. I would think all these poppet valves have to be together and right next to the related spool valve. One thing I think is not the issue but want to mention. I noticed that I have one 90 degree fitting that has a slight bend to it. It's on the hose that would pull the dipper in. I took the hose to a hydraulic shop and was told it was not causing any restriction.

Yep. Just for review.....A backhoe spool valve array is composed of a bunch of identical spool valves bolted together like a sandwich so each spool can work individual BH cylinders while sharing common high pressure and return circuits. And each spool valve has its own team of small identical protection poppet&spring valves mounted on it.
Most common is for each spool valve to carry an upper combination reliefs/anticavitation valve, a lower comination relief/anticavitation valve, and a single centrally located load check valve.

So one guess now is that one of those safety valves associated with the dipper or boom spool valve has some crud caught under it and is providing a path for high pressure fluid to escape.

If you had the shop manual, with decent hydraulic diagrams you probably could figure out which particular valve is not working right by logic & comparing which functions are not working.
Some people even claim they have gotten BH checks and reliefs working again by extending a boom or dipper and then letting it drop an inch and "bouncing" it repeatedly to get crud to move. It might be worth a try...but I'd be careful and if it doesn't work not pursue it.
luck,
rScotty

 

[rScotty]

Some pictures from Messicks.com

New Holland 555C - 4 CYL TRACTOR LOADER BACKHOE(11/88 - 08/93) Parts Diagrams

New Holland Parts Catalog Lookup. Buy New Holland Parts Online & Save!

www.messicks.com

Looks like it only has a single system-wide load check valve (24 or 29)
But there are the paired relief valves we were discussing clearly shown. From their complexity I would guess that the anit-cavitation function is included.

Text says parts are discontinued... That's something I haven't run into much with our JD310.
Where do you go for parts? A spare brand new set of relief valves would sure be handy.