Hello friends. First off I want to let everyone know I am not a professional heavy equipment operator or mechanic but I am mechanically inclined. I bought a 1997 New Holland 555e about two years ago to use around the house. The hydraulics have always been slow but it got the job done. Now they are slow and very weak. Especially after it heats up. I am to the point where this needs to be fixed. Here is what I have done and checked. About a year ago I rebuilt the pump but that didn't help I checked flow at 1000 rpm I got 12 gpm. I did not check it at 2200 rpm. Book says 21.4 at 2200. I checked the main psi cause I was going to see if the main system relief valve needed adjusting. Book says 2725 psi at 1500 rpm. I barley got a 1000psi. So I moved the adjustment on relief valve both directions and nothing changed. I am lost as to what to check next. If there are any suggestions I would sure appreciate it. I hope I have gave enough information but if not I will be glad to add whatever is needed. Thanks again
I would suggest a god flo test done and the pump output checked with hot oil. Hydraulic systems typically run well above ambient temperature, maybe 100 degrees above. I do not know what your pump rebuild consisted of but I generally do not advise rebuilding unless the pump was simply leaking. The pump can only be evaluated at hot temperature and the flow checked while the unit is at full pressure. Others may differ but I feel that the pump efficiency is marginal if it drops under 30% efficiency under full load. I said a lot to just say that all your symptoms point to diminished pump flow at warmed up temps. Retest hot and under load and repost results. The best way would be to test only the pump back to sump but this must be done carefully as the flo tester must be controlled to keep pressures safe.
Are the hydraulic filters giving the pump enough oil to do its job. May have been changed but never seen it mentioned.
Yep, you need a flow tester with load valve and pressure gauge coming right off the pump. You really need book specs, but just as a for instance if you get 12 gpm at 1,000 rpm hot with no load, and then you increase the load pressure to say 2,500 psi, recheck rpm at 1,000 and your flow meter says 8 gpm, then you are losing 4 gpm to heat at that pressure. If you're only able to get 1,000 psi with a function deadheaded then either the pump is in very poor condition or you have a bypass leak somewhere in the system, could be bad relief valve or simply some o-rings need replaced. Again, testing pressure with the proper flow meter at pressure right off the pump will give you more clues.
My probleme gonna be finding the proper flow test meter unless I can find a place that rents something like that. The reason I rebuilt the pump was because the guy I bought it from suggest it. I got it fairly cheap so figured I could put some money in it. Yes all the filters have been changed.
You may be able to either take the pump to a shop and have them test it, or pay to have a field service tech come out with the flow meter setup. If you have a full pressure flow meter and a pressure gauge you can get a three port relief valve and a needle valve, build up something that will work. As melben says though, you have to be sure not to deadhead the pump or induce a higher pressure than the pump is rated for, or you will probably have explosive decompression. If your flow meter is the type that can withstand full system pressure on the outlet port, just hook it into the line between the pump and the valve, check flow with no load and then deadhead a function and note the difference in flow.
thought i would add this.
the above pics is the locations where the test was done
Can you elaborate more on buillding this tester? The meter I have is rated 5000psi I also have a 5000 psi gauge
Here's a drawing from a website of the internals of a typical flow tester box (shown inside the box of dotted lines): And the link if that's not readable: http://i.ytimg.com/vi/5POaSPGI2yY/maxresdefault.jpg You just tee in your pressure gauge ahead of the flow meter, put a needle valve in the outlet from the flow meter to load the circuit, and a relief valve teed in between the flow meter and the needle valve, you can either tee it back in to the outlet, or run a third hose off to tank from the relief depending on your needs. The relief valve is so you don't deadhead the circuit with the needle valve. Most testers these days have a "rupture disk" which blows out if you exceed the rated pressure of the tester unit, I prefer the adjustable relief myself.
I see the book says to hook the tester into the boom lift port on the backhoe valve, is that where you did your flow test?
Yes that is the location. I just went off what the book says
Today I dug up a tree stump mainly just to get it operating temp. I was told to take a infrared temp gauge and check all connection points. If there is any blockage it would generate more heat at that connection point. Everything was around 125 degrees . The output connection on the filter was the hottest spot at 140 degrees . Still working on flow meter
Eliminate the steering priority valve from bleeding off oil intended for the work circuit. I have no idea where yours is located, but the manual should be able to provide the diagram of the crcuit.
Are you saying to shut off the hydraulics going to the steering valve? The 555e has a two stage pump. The rear pump operrates the steering
That book is really hard to read, but after some more looking, the flow from both pumps is combined at the backhoe valve, so if you're checking flow off the backhoe boom lift, you should be seeing about 17 GPM rather than 12 at no load. The relief valve for the smaller rear pump which also supplies the steering oil is located in the stabilizer valve, might be good to check that and see if you're getting the specified 2565 psi. Here's a question: do the stabilizers lift the machine up handily, like they're working as they're supposed to? I'm not sure but typically the front pump flow will go to the loader valve first and then to the backhoe valve. The book says the pressure setting for this pump is in the loader valve so it sounds logical. I'm starting to suspect the front pump may be weak, or you have a duff relief valve.
the stabilizers do lift the machine up to a fully extended cylinder and about 5 secs to retract. Thats at about 2200 rpm. I'm attaching some more pics that might help. I want to thank you guys for taking the time to help me on this.
Sounds to me like the smaller rear pump is working fine, good power and speed from the stabilizers and I assume since you haven't mentioned it that the steering is fine? These new pictures are very helpful, the rear pump oil flows through the stabilizer valve and then joins the front pump oil inside the loader valve. If there's a test port on the stabilizer valve or the rear pump you might want to check it by deadheading a stabilizer cylinder in the up position. So... it would appear to me that either the front pump has some serious internal bypass, or the loader valve system relief is stuck open or is not seating properly thereby allowing serious bypass there. Or it could be nothing more than O-ring seals on the relief cartridge, you might pop it out and see what the seals look like on the stem of it. The parts book doesn't show any seals, just calls out the complete cartridge at $247 There may be other possibilities but those two are the most obvious. If the relief cartridge seals look okay, any chance you can pick up a check valve and put it in the line from the front pump to the loader valve? Then recheck your pressure, is the test port on the loader valve itself or at the pump or? The check valve would prevent oil from flowing back to the front pump, IF that is what is happening. Or does your flow meter have a check valve in it, or is capable of handling reverse flow? Would accomplish the same thing for testing if you could put the flow meter in line between the front pump and the loader valve, as long as reverse flow won't damage the flow meter if that happens.
Today I took the pump Off. Seals were bad along with some other things. Cant really tell if pump is rebuildable or not going by what I read in the manual. This is a Parker/Ultra with the model number 9555S Ser number 13-02-258544-006. There is also a 8877-902-DON cast into body. Any idea what this really is I can not find anything as far as a rebuild kit or replacement. Thanks
Can you replace the bad seals? What are "some other things"?
Im sure the seals can be replaced. The bearing blocks is what looks like needs to be replaced along with the seals. Just not finding anything yet on parts
I have not found a sub for that pump assembly either, the seal and gasket kits are still listed, You really should have found someone with a flow meter before pulling it down to check the flow. The main relief in the loader valve could have been swapped with the stab valve relief to check it's operation. How is your machine set up, does it have a 4x1 bucket, extenda hoe, or the valve for the hammer, or the valve for the hyd hookup for hand held tools ?. Their is also several different loader valve setups depending on the 4x1 and hammers. Coming off the boom circuit with the flow rater is the way to check the front pump and rear pump. I am working on a 555e that lost the 4x1 and stab pressure at this time, waiting for the rebuild kit for the steering sector along with it's check balls and check valve. The steering circuit is sending a signal all the time to shift the spool in the end section of the pump dumping the oil to the stab valve and the 4x1 valve mounted to the loader valve. That main pump unit is around 1300.00 complete, with the (3) seal kits running around 500.00 and a end valve priority 500.00 it's almost a toss to put a new pump on. If my steering valve repair doesn't fix my issues. If you replace your pump unit I may be interested in your old pump priority valve end section.
From the look of the seals (what was left of them anyway) it was going to need rebuilt or replaced. From what i am seeing the rebuild kits do not include the bearing blocks #5 in the pic. The manual says if bearing blocks are bad the whole pump should be replaced. How can I tell if the bearing blocks are really bad or if just a little cleaning and polishing is all that is needed? I believe this has the valve block for the hammer. Im not familiar with the stab valve... Thanks for the input.
How many hours on this machine? According to your first post you rebuilt it once before... Going by what SHEEPFOOT said about the prices, I'd say at this point a new pump would be your next move. And pray that fixes your problem.
Hard to say how many hours. According to the guy I got it from the instrument panel caught fire and had to be changed out . I do know it was a rental.
I have also tried to locate some of the bearing and gears with no luck. You will need your pressure gauge if you replace the pump to both set and check the stab valve, loader and backhoe valve reliefs. The steering relief should be factory set and has a freeze plug covering it, and only comes in the end section seal kit that's well over 100.00 bucks with those four basXXXX sized O-rings. Remember to go easy checking pressures with that new pump until you set your reliefs if you go that route.
I'm honestly starting to think I did not rebuild this pump. I had a old Massey backhoe that I know I rebuilt which I no longer have. I have had this New Holland longer than what I remember. The wife seems to think I have had it around eight years. Time flies . Where have you found a new pump for 1300.00?? Also what is a stab valve?
Whenever you rebuild or replace a pump, it's always the better part of valor to find all the main system relief valves and back them off a LOT. Never hurts to start out way low, however the opposite can bring you to tears when you deadhead a cylinder with no port relief and that shiny pump you just put in grenades a case or snaps a shaft off, and that's best case. I have seen the aftermath of this, and the tears on the parts counter where the brand new high dollar pump lay with a large open crack from one end cover to the other in the gear housing. Other possible failures like hoses or cylinder barrels can be just as sad, and may include personal injury. When pumps get tired, people tend to screw in those relief valves, and keep screwing them in, sometimes until they bottom out, and even though it doesn't help any, they never seem to back them back out.
New holland shows two different pumps, with different seal kits. If yours is the old style you could just reseal the bigger pump section and give it a try, since your steering and stabilizers seemed to function properly that would indicate that the smaller pump section and the load sense valve section are working fine. Looks like $270 for just that seal kit, again assuming that's the correct pump. Does yours have a thin flat separator plate between the two pump sections? I think the serial number break is 031007793 but who knows if yours might have been updated one or two steps newer. The reman seems to be available at a shade over $1,200, the new and improved update substitute is nearer two grand because you have to have additional parts to adapt the plumbing.
this is the pump i have
Whoops, that would appear to be the newer unit: This seal kit is complete except for the valve seals and runs $330 from my local dealer. There is one newer replacement pump that is also now obsolete, and another current update, apparently you have to change a hose to make it fit. Fun.
The stab valve is #6 on your chart showing the different assemblies and oil flow. I should have said the whole word stabilizer. In the pick it shows it also having a extenda hoe valve section. You can see the relief valve also in the pick, it's mounted on the lt side, above the rear axle, front side. I see someone has also been working on the steering relief valve on your pump since the freeze plug is out of it also.
This may be a silly question but this explode view shows the orientation different from how mine was mounted . The pump is the same. Would the orientation make a difference
As long as the ports are connected up right, the pump doesn't care which way it sits. The big flange port is the common suction so I don't see how you could get them mixed up?
Yes I noticed that also. I could tell also there was red silicon on the mounting flange so who knows what has been done to this pump in the past. I really thought this was the pump I had rebuilt but after I got started on taking it off nothing looked familiar. So it must have been the old Massey I'm thinking of.
What do you think about the bearing blocks? The ID looks good but just wondering about the surface wear. Also threw in some extra pic of the hoe and dozer I have.
I think the appropriate term for those would be "knackered". Might be able to machine them smooth, but then they may be too thin. Worth a try I think. Any chance they were put in backwards?
Got the seal kit in yesterday and started the rebuild. Right off the bat I discovered the the old back up seals and rubber seals had been installed backwards. I'm not sure how much effect this has on the pump but it sure can't be good. Today I plan on finishing putting hoses on. Then I have a swing cylinder leaking I'm going to fix while it's in the shop. Hope this fixes my problem.
So then your sure you didn't rebuild this pump. Someone did if the seals were in backwards... As long as your sure their going in the correct way now.
I don't think I rebuilt this pump. If you look at the pic of bearing blocks the plastic backup seal was installed first then the rubber seals. On page 2 the exploded view items 3 and 4 shows rubber seal first then plastered backup seal. . I put them in the way the book shows..
Ok I got the pump back on backed off the relief valves double checked everything. Started it up put pressure gauge on the appropriate check valve location and could never get any pressure to build up. 1000 psi at the most at @2500 rpm. Hydraulics would not lift the backhoe at all. Gave up for the night. The next day after work I went to check to see if any change and to my surprise the hydraulics was working better than ever. So I decided to do some digging. After about thirty minutes I went to check things out to see if there was any leaks and there was fluid pouring out the pump. So I stopped immediately, got it back to the shop took the pump back off. Found seals blown out on front section of pump. Which is the main pump. So know I'm looking at more seals. I think I know what happened. When I first started setting the main relief valve I was getting no change in pressure. I had it screwed all the way in and no change. Hydraulics weak. That's when I gave up. Then next day when I tried again the relief valve was still srcrew in. Started it up and it was like something gave way and started working. Buts that's also when it blew the seals. My question is why was I not getting any change in psi the first time I tried setting them. Then the next day after work I touch nothing and then bam starts working.
I have a question about setting the main relieve pressure valve the book says to activate the front loader and make note of the pressure that it should be somewhere around 2500 psi. Is that 2500 while cylinder is moving or at deadhead.
Deadhead. At 2200 rpm according to your pic in #17