Hi All, I bought an old Pettibone articulated loader, backhoe. This thing is heavy duty!! Nobody around here, BC Canada, has ever heard of or seen one or seems to know anything about it. I just love this old iron though. 453 detroit, allison powershift trans, 4wd, articulated, runs like a dream! EXCEPT, the backhoe groans like an angry grizzly bear under any kind of load, even lifting the empty bucket. The supply hose is vibrating right out of the clamps its so bad. The loader works GREAT. I dont know much about hydraulics but I am betting its probably something simple. Any help or suggestions would be greatly appreciated. Thanks is advance. David
Sounds like cavitation. Have you checked the fluid, and/or filter or strainer?
Yes, I checked the fluid, it was heavily contaminated, opened and cleaned the tank, changed the oil in the tank, (40gallons aw32). The filter (in the return line from the hoe) is a canister that the filter element is missing from so no filter at all at this point.
Also, adding to my confusion, is the loader works smooth and quiet.
Same Grizzly sound using the Loader? ( front bucket hydraulics) Empty or loaded
Nope, loader is smooth. I traced the line from the pump, it goes first to the loader control block and then out to the backhoe control, then return to tank. There is also a return to tank from the loader control block. (if that is of any help)
Sounds like the problem may have come from contamination. I'd start with a hydraulic filter. Since you're new. ....have you tried posting a test picture here (other than your aviator) Is the machine indoors or out.
WOW, it worked! How cool is that!
outdoors but under cover
Very Sweet looking machine. ...4wheel drive and a Detroit ! I'm Jealous. I thought it snowed and was cold every where in Canada. ...guess not. You must get a filter. ...seems you did run it with out one to test it. Bad. Wonder what would the oil in the cylinders look like. ....plan on cracking some lines loose.
No hydraulic filter # yet?
Thank you. It really is a sweet old thing. My wife thinks I am a nut though! Oh man, the oil was so bad!! I had the two backhoe boom cylinders rebuilt, SOOOO much sludge, and the two big arm cylinders on the loader, same. I have messed around with the relief valve on the backhoe control but, I am way over my head there. I THOUGHT it had a filter but to my surprise (while I was tracing the lines the other day) I realized, it was the transmission filter I was looking at. DOH!! No snow in Canada! Where ever did you get that idea? ;-) I hear it snows a lot in Buffalo though!
I took the canister apart, no element, no numbers anywhere, not sure how to deal with that one either!
Take a picture of the can... maybe someone here knows
Good plan. I will do that when I get back there in January. Working outta town to afford these hobbies!
Congratulations it only took me a year to figure out how to post a picture! FYbottom cliishing for filters I have. ... Google for instance x (enter) then at the bottom click images x; Detroit hydraulic element Petitibone. hydraulic filter then look for a picture that looks like yours some even have the filter element with number showing
Good on you ,,,, I still can't....lol
Contact the folks at www.tiffenparts.com . They can most likely tell you anything you need to know about that machine. They also have, or can get parts for it.
It's easy as pie with a smartphone. But if you don't have one, then I guess it's not.
This is Grandpa we're talking about. :beatsme
I did the google thing that fixou suggested and got the contact for.......Tiffin Parts......that Mowing man suggested. Thanks to both of you. So I phoned them and they are researching the filter for me. That said, do you guys think the filter will fix the growling in the hoe hydraulics?
The filters will help in the long run but , I doubt that is the problem. What kind of power does the boom have? The line that vibrates, is it from the loader control valve to the hoe valve? Sounds like a valve is stuck. Can you post up model and a serial number?
If the front loader is quiet and smooth but the backhoe end is giving the noise, I'd suspect either worn cylinders, a valve(s) worn internally or even possibly loose linkage allowing valve(s) to "chatter". Is the noise more pronounced in one function more than another? Boom up/down, stick in/out, bucket curl/uncurl or side to side swing? Same thing with lowering/raising the stabilizers? Joystick controls or sticks for the backhoe?
The old 'beast' is a 1973 Pettibone Model B-417. Serial# 7310001 The boom power is ok, it'll dig, lift itself, push the machine up off the ground etc. The line that is vibrating IS the one from the loader control to the backhoe control. The noise is only under load, performing ANY lifting or swinging functions on any hoe components. Relaxing or lowering motions are quiet if done slowly. Lifting movements are loud and get louder the faster or harder you push. The controls are push/pull sticks, curl, crowd, swing, lift and stabilizers and yes the stabilizers growl too. Those two cylinders are new. A neighbor told me to stick a dime under the relief valve in the cartridge. That did not help, made it louder and bent the dime!! (Crazy right?) Thanks for your interest guys. Any ideas?
You need to quit listening to any neighbor or pretend expert about messing with or adding dimes to relief valve springs. Relief springs are usually stiff enough and adjusted to hold thousands of PSI. The thickness of a dime could easily put a needed relief completely out of operation at any reasonable pressure. There is a precise procedure for adjusting the valves on the hoe bank and some are high pressure secondaries which operate above main relief requiring oil to be forced back through them with an external pump to adjust them. Blown hoses and split pumps and bent cylinder rods are a result of dinking with relief valves. A word to the wise................get professional help before you create major problems(expense).
Roger that melben! Exactly the conclusion I came to before thinking perhaps there was better advice to be had here, which, happily, I am finding to be true.
If you don't have this solved yet it could be a power beyond valve problem that should be where the pressure line exits the loader valve
Thanks OldIron. I am beginning to suspect the same thing from other reading I have been doing. That will be what I look at next. Do you know where I might get more specific info on power beyond valves? It seems that rudimentary diagrams are abundant but specific 'how it works' info is tough to get.
My ques would be the rear spool for the backhoe. Half of it is transferring/passing oil as it should, the other half ( that controls your stabilizers and dipper) is probably still clogged with junk and not allowing proper oil flow. The stabilizer want's to work, but it just isn't getting the flow it needs.
Sorry to write but, I believe it is a lost cause, you will NOT be able to fix... What you need to do is PM me and I will send you the info on where to send it.
As far as I know, a power beyond valve is just the first valve in the series that is set up to allow pressurized oil to the next valve. The power beyond valve just has another port to supply the other valve bank (backhoe) and a plug to block the return flow. When assembled they function like they are one valve bank (except the first one has priority if it's in use). I would guess the problem is in the loader valves. You could try operating one function from each to see if you can get the backhoe to operate quietly by moving the loader valves slightly off center. With a 40 year old machine, take nothing for granted. The linkages could be holding something up a little. Broken return spring in one of the caps. Also, you said the return from the backhoe goes to a filter canister with no filter. Does the loader return also go through this canister, or straight to the tank? That could be significant to the functioning somehow. I'm assuming this is a gear pump hydraulic pump, could you post a pic of the pump, or just confirm that it looks like a typical gear pump, not a piston pump. And when you say the supply goes to the loader valve and then to the backhoe valve, does it go in one end of the loader valve and out the other, and then on to the backhoe valve?
Thanks HookedOnDiesel. I will consider that too. Sorry MadDog. Failure is not my strong suit. From the reading I have done on this forum I know there are lots of smart and savvy enthusiasts who are happy to help. I will plug away at it. I have a lathe, a welder, plenty of duct tape and lots of time.
Thanks Delmer. I think you are right. In fact, once while I was digging I had occassion to reach around and lift the loader while I was stretching the boom. The noise quit but I am not sure if the movement also quit because I wasnt watching the boom. I assumed that the loader circuit robbed the pressure and that was it but I remember thinking it might be significant. The pump is a gear pump. Big bugger about 10" diameter, slightly oval. The return hose from the loader controls goes directly back to the tank, not through the filter cannister. Hmmmm. Not sure about the physical configuration of the loader valve. I will have to look at it when I am next in the same town as my machine. That will be February. You have given me some great clues here and I really appreciate it. Thanks.
OKAY! SO.....Filter installed. Re plumbed supply directly from pump to backhoe control bypassing loader all together. Plugged main relief by gutting it and installing a carriage bolt through the center. Noise and vibration still here and seems to be coming from the pump. Pump is a Denison. Anyone have any experience rebuidiing one of these?
If the loader ran smooth and powerful then I would think the pump is fine. If the backhoe return flow was somehow getting air into the reservoir without the loader return doing the same thing, that might cause cavitation only when using the backhoe. Cavitation is the most common thing that would cause the chattering, and you'd feel it in the pump and pressure lines. Or there could still be something wrong with the backhoe valve? haven't seen that yet...
Hi Delmer. Thanks for your continued interest. I agree with all of your logic. My thinking at this point however is guided by the fact that the pump is 40 years old and could surely use a peak inside anyway particularly since its been getting this beating for some time. Also. I have been told that it is a vane pump and that they are notorious for this behaviour when the flights wear down, so, based on that, and that the removal of the pump will allow access to replace the supply line to the pump and rule out any gremlins there, we are rolling up our sleeves and GOIN' IN! Wish me luck!
Any update, Pettiboner? Ya got my curiosity aroused now...
Well the update is that when I get laid off work in October I am going to rebuild that darn pump! But I did change the transmission oil when I had a free day last month! What an ordeal THAT was. The book calls for Allison type C2 (which turns out to be delo 400 30 weight according to Allison) but it had red oil (dexron?) in it. I found a great source for the Allison Transmission manual though, FREE. Lots of other old iron manuals too. Www.numeralkod.com
TY for the reply and for the link to manuals. Today was the first day I've actually gotten any work done with my 530CK basket case project aka "The Great Hoe of Babylon" which I sorta chronicled briefly here in someone else's thread: HeavyEquipmentForums . I managed to dig and move about 20 full loader buckets 50 yards or so before she decided to sputter and stop smack in the middle of the county road on which I live. Had to run her on the starter to get her on the shoulder halfway out of the way of traffic. Since I'm a complete noob with diesels I had no clue. Probably a good thing I had about killed the battery using the starter to move it and was able to run a cord and charger to where she sat. I had a little time to think and finally decided it wasn't getting any fuel...cracked the tank cap open-I can see fuel, only ~ 2 clock hours ago dumped a full 5 gallon can in the tank. Checked the fuel needle valve, maybe they can vibrate closed? Nope, it's wide open still. Opened the bleed screw on the filter-nothing-hmmm... Well, I HAD been on a bit of a slope just a minute or so prior to the sputtering/dying so just maaaybe it was fuel...dumped my last can of fuel in and opened the bleed again-VOILA! Now, I know all you old dieselheads knew what was wrong at "sputter and stop", but for me this was pretty heady stuff to be able to figure out the problem and not go off the tracks when I saw fuel still in the tank. Maybe there IS still a spark of hope for me to be able to get my money's worth out of this 50 year old hunk of iron...
You go OldPhart! Great Hoe of Babylon indeed! I LOVE your madness!!
Maybe you should get the name Babaloney Hoe tattooed on it!
SUCCESS!! There is no point in having time if you dont have perseverance to go with it! I pulled the pump and took it to the hydraulic shop in town. They said, yes its worn but probably NOT the problem. I said well, lts refresh it anyway, they said we will see if we can find parts. 6 months later they til had not "found" anything so researched it. If anyone is interested, here it is. Denison was acquired by Parker hydraulics. No Denison replacement parts available. I called Parker, they put me on to ATTICA hydraulic exchange in Michigan, who do aftermarket stuff. They had a replacement 35gpm cartridge for $675.00. Long story short, it is back in and running PERFECTLY. I can hardly believe it! Thanks everyone for your input. David
Nice success story David , Good to hear!!
That's quite a machine. Kinda reminds me of the old Dynahoe with the same size fronts, 4wd, and a Detroit. Nice happy ending to this one.