I am hoping for advice on whether I need a new pump or if there is a relief valve I need to check somewhere?? I have a ford 555b that I bought back in Feb and have been having pretty good luck with it up until the last couple of days. I am in Texas and the temps have been in the lower 100s when the probs started showing up. In using the hoe I would dig for about 30 min (am guessing here) and the boom cylinder would start slowing down in pulling the loaded bucket out of the hole. It was a very noticable slow down to the point that I tried reducing to about 1/2 throttle to see if that changed anything. At 1/2 throttle the boom would not lift the hoe section with dirt in the bucket (this was with boom and dipper extended at about 60%) If idled it without using anything for several minutes it would start working again, but would go back to slowing down. I have had a whine when using the loader, but have always had plenty of power until this started happening. I have noticed a bit of a decrease in lifting capacity in the loader as well. In placing my hands on the metal lines of the hoe when this is going on they are hot enough for me to have to remove my hands within 2 sec. I do not have a hyd oil temp, but pulling the res dipstick the oil feels wam but not hot. I am assuming the oil cooler is doing its job at least to that point. I have good trans drive and reverser power all seems ok. I checked the main relief valve press on the hoe part and had to raise that back up to specs about 2 mo ago and the boom press was within the specs and I didn't have to do anything about that one (this is 2 months ago) . The hydraulics have not completely quit, just slowed down and lost power recently. It is still able to work, just when it gets hot I have to make adjustments to how I dig, meaning things it would normally pull through I would have to stab at and move the bucket around to break up the ground more to get through. The weakness appears through all cylinders both loader and hoe. Some of the cylinders are more readiliy apparant like the boom and the lifting cylinders on the loader, however all the cylinders appear weaker than they have in the past.
when mine starts slowing down, i look straightaway at the hydraulic filter. that clears it up everytime.
Could be a number of causes with this one. First things first; what shape is your hyd oil? Is it clean/clear, or is it milky (contaminated with water)? The heat is very not good. If you place your hand on a component and have to pull it away within 2 seconds, your pushing the 200 degree range. Hyd oil (depending on type) can start to break down at temps between, say, 150 and 190. If there's any water emulsified in the oil, it will boil at these temps and turn to steam inside the pump. I'm only saying this to tell you to be careful with the high temps. If it turns out that your pump is OK and the problem is something else, your killing your pump with these temps. Correct me if I'm wrong, but didn't the 555B have the main relief valve on the backhoe control valve. I have had these fail before on these units having the same symptoms as yours. It's one of the few times I've replaced a cartidge valve with an OEM replacement and found you had to adjust the new valve to specs. In most cases, the valves come pre-set fairly close to spec.
I replaced ALL filters except the power steering filter, immediately after I purchased it and replaced all the oil in the unit from the front to the back. Oil looks fine and the oil itself when I rub it off the resevior dipstick on my hand is warm, but does not burn, does not smell burned and still "feels" like the viscosity is ok. In other words the oil at the top of the resevior(at least where the dipstick can reach) is not runny or scorched.It would be a guess, but I bet I don't have but 40 hrs on it since I bought it in feb and changed all the filters and oil. Yes the main relief is on the back hoe control block and it was running about 2300 psi so I bumped up to I believe about 2500psi (whatever the spec was- I don't have the book infront of me) I can pull the hyd filter off easy enough, but like I said it is new as of 5 mo ago. I was leaning toward the pump only because it is an older unit, and both hoe and loader seemed to be affected. Hoe is just more noticable because the capicity is less than the loader weight wise.
It sounds like your problem has come upon you rather rapidly. Could be related to the outside temps, but on the other hand, we don't see tons of posts about 555 Fords slowing down because of high outside temp. I don't know a way you could test your pump to be sure, but I would think if it has gone down rather quickly, there should be some metal in the system. Remove your hyd filter carefully. Pour the oil in the filter in a clean container and see if there's metal in the oil, especially brass. Now, place the filter in a container with some mineral spirits and rinse the filter media. If it's a spin on filter, pour the M-S into the filter, place your hand over the end of the filter, and agitate the liquid. Pour it into a container and see how much metal comes out of the filter media. A good bit of metal, again...brass, is a good indication of pump failure.
Thanks ATCO, I will have a look at the hyd filter in a day or two. Yes the problem did seem to come on pretty sudden. This is my first back hoe so don't have anything to judge it by. The load on the hoe is still lugging the engine, maybe not quite as much as it had in the past (this is subjective and could just be me). One question though. When it does slow down/quit the most, I don't recall hearing the relief by passing the fluid as if it should if the pressure is building up and hitting the relief pressure. Is that more indicative of pump failure? I just thought about that and will have to verify it by using the hoe again. I will definately pull the hyd filter.
One more thing, it was not really difficult to test the main relief on the hoe controler. If it is failing in some way like you suggested earlier, would testing it again with a psi guage show anything worth while?
Hey, your there with the machine, you can tell way better than we can what it's doing. As for whether it's indicative of a pump failure, that's hard to say from our end. Yes, it is suspect, if, the machine is stong at cold start, then progressively get's slow as the fluid warms, and, since it has equal effect on loader as well as hoe. It's been a number of years since I've worked on a triple nickle Ford, so I don't remember the components. Gear pump, hydrostat pump, I don't remember. But, generally speaking, if a relief valve is failed and causing the problem...it's failed, they generally don't "work cold, then crap out warmed up". It's hard to pinpoint at this point where your problem lies, that's why I sent you to the filter; if you find brass particles...they came from the pump.
It is a gear pump out front of the radiator, and yes it progressively gets worse as it warms up and gets under a load. Thanks again and I will check the filter as soon as I can get a chance, maybe thurs.
If it's a gear pump, and it's an elder (B series) machine, it's probably an open circuit hyd system, fluid flows through the system when no functions are operating, and this flow of oil is constantly flowing through oil cooler. Very simple hyd system. Pretty much control valves directing flow of oil and relief valves to relieve system pressure when a cylinder deads out or load taxes the system. And I'm thinking the steering system is controlled by a different pump mounted on engine, can't remember for sure. All the info you've provided points to the pump...I hope the filter rinse gives you some confirmation.
Hey ATCO, Got the filter pulled yesterday. oil and filter had metal shavings and grit in it. Grit appeared more dark in color almost the color of crushed pencil lead, but I am sure it is metal. I drained the filter into a large glass casarol dish (for my shop, not my wife's,,lol) The shavings were heavy enough to drop immediately to the bottom and you could rub your finger accross the bottom and pick it up on your finger. You could also see it on the filter itself so I didn't need to rinse it. Oil once I drained it into a clear plastic container was darker than it should have been if it was ok. Wasn't diesel motor oil black, but was not as clear as it appeared to be on the dip stick.All in all I am pretty sure my pump crapped out. Unless you think there is something else I should look at I am going to order a pump for it. Thanks for the help. Mark
yes the steering has its' own pump, and I believe the tranny and diff are seperate as well.. At least I have to drain and add the oil all in seperate places so that leads me to believe that none of the systems are interconnected ( sharing pumps and oil) Now I just hope I don't go blowing a bunch of seals and hoses with a new pump put on,,,,,,
I'd say your probably right, least that's the way I'm leaning. But, if it was me, before I purchase a pump I would like to verify my suspicions by taking the pump off and taking it apart. If you are going to replace it, your going to be taking it off anyway. I'm near certain it's going to have a gear pump, they're pretty easy to dismantle. Once you get in there, if the pump is trashed, you'll see the evidence of it. Be sure and send some pics.
not saying you should run it. but from what you found in the filter, it would sure slow things down because of plugging the filter. the black powdery lookinf stuff could be deteriorated carbon from the inside of the hoses. we get that a lot on diesel rigs when the fuel turns black. had to do analysis to find out what it was. 5 months on a filter will pick a lot of metal in a system that is wearing. check your pump as suggested and look for wear. pf one is needed. try surplus center. com
Well it was not "powdery" at all, it was a hard grit-like substance and in most instances it was a dark greyish to silverish color almost the color of pencil lead or welding slag. It was hard and did not break apart when I rubbed it between my fingers. After looking at hydraulic schem. of the hoe, the hydraulics are contained to the loader and hoe only and have NO operational flow to any other part of the tractor ( ie. tranny, etc). I can not figure any other way for the "grit" to get into the system except the pump crapping out. QUESTION- In replacing the pump. Should I drain the oil, replace the pump and run it for a while (30 min moving the cylinders) THEN replace the hydro filter? Or should I just replace everything prior to starting it? The reason behind my ? is that I am sure there are still pieces of grit floating around in the system and I thought I could float them into the old filter prior to changing it. Is this a good or a bad idea? Mark
Yes, it's a good idea. How to do it, that's a tougher question. Drain and clean the tank for sure as there's probably some debris in the bottom of it. I say this because most hyd return filters have a bypass valve and if you have (unknowingly) run the machine with a clogged filter it would open the bypass valve and dirty oil would go into tank. The oil in the rest of the system? That's a little tougher. Unless you've got access to a filter cart (which most folks don't) it's difficult to flush the entire system of old oil and replace with new. There is one method I've done before, but it has a lot to do with how your filter is arrainged. Can you disconnect the hose going into the filter, or hose going out of the filter to tank, then stick that hose into a good size drain tub?
I may be able to disconnect the line going into/out of the cooler prior to getting to the tank. I would have to look it over to be sure. Even if I can I would have to attach a hose somehow to get the fluid into a tub or bucket. I am assuming you are going to get me to put new fluid in the tank and just run the machine for a designated amount of time to get the new fluid to push the old fluid out? I do not think the filter was ever clogged to bypass levels simply because it did not appear overly dirty and has only got about 40-50 hrs on it. I could see particles in the paper, but the paper was readily visible and did not seem to be sludged up. I know this is a subjective thing and I could never be sure. I am thinking if I flush the system in this manner the only part of the system not actually flushed will be the cylinders them selves. Is this correct? My understanding is that the fluid will flow through the pump to loader and hoe valve blocks, but just recirculate back to the tank without going through the cylinders. Is this the way it is working? (pump out in front of rad, on drive shaft off crank- pump only has fluid in/fluid out so if it is running it is pumping fluid I believe)
Sorry it took a few minutes to get back to ya tx swordguy, I was working two other threads. Your sharp as a tack, got this thing pretty much figured out. I would drain the tank, you described the oil as being black nasty, so it's getting drained and some new oil is going in. At this point, I always try to open the tank and clean it as best as possible, but then, you may only have a fill hole to work with. Your right about the fluid circulating on you machine, that's what an open center circuit does, and it's what we want to avoid, having nasty oil go back into the clean oil we put in the tank, hence, the return going to a tub. And, yes, there will be nasty oil in cylinders and components. We're going to get most of it out, but it's not possible to get it all, we'll settle for most. You can do this with the old pump or the new, don't see where it makes much difference. Here's what you do; roll the loader bucket all the way forward, lower the loader arms to the ground. Outriggers up. Curl hoe bucket, fully retract arm, hoe boom down until bucket links rest on ground. Drain/clean tank, hose to or from filter in tub. Fill tank. Now this is where you might want a helper to watch tank fluid level. With a full hyd tank, pull your loader lift valve to raise position, start/run engine. Loader will raise, clean oil will fill one side of the cylinders, nasty oil from other side will go to tub. When the loader gets to the top, roll the bucket up. Shut down engine. By now, you probably need a tank re-fill. You get the idea now. Next, riggers down. Then roll out all the hoe cylinders. By doing this your remove the most nasty oil you can. Just make sure your operating some function while the engine is running. As soon as you reach the end of a function, shut her down and check oil level.
Thanks for all the help ATCO. one ? how much oil should I get in order to do this? I am thinking at least 10 gallons (being very hopeful, but realizing probably more). Also would it be a good idea to change the filter again say 40-50 hrs from the pump replacement?
It's hard to say how much your going to need, but I'd say your right...probably more than 10 gal. I'd get at least 30 gal., as long as you don't break the seal on the bucket you should be able to return any unused oil. And, yes, I would remove the filter after that many hours and clean it as mentioned before to get an idea of what's going on in the system. I still want to see pics of your disassebled pump when you pull that puppy off.
I finally got the pump changed out and it is like a totally different machine. At idle with a full bucket it lifts and works like it had been doing at full throttle. I have not taken the pump apart to see exactly what went wrong, but so far it is not even the same machine. I flushed the fluid (approx 20 gallons through and it is still abit dark, then put in a new filter. I ran it hard for about 20-30 min at full throttle and then laid my hand against the steel lines running up the back of the hoe sections. They were hot to the touch but I could leave my hand on them for as long as I wanted to (before about 2 sec and I was pulling my hand off quickly). I then operated it in idle and the lines cooled down quite efficiently. The biggest pain in the whole change out was finding a place to cut the original hard line and re-flare it because the new pump pressure line was about 2" closer than the original. I ended up having to drive 40 miles to get it done. Anyway it is working now and I am happy. The only concern is the oil is now a bit dark again, however the noises and heat are not there anymore. I figure that I was just unable to completely flush all the dirty oil out . I appreciate everyone's help (especially ATCO) Thanks again. Mark
It's fixed, excellent! :woohoo :drinkup