AC 715B backhoe question
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=11226
Printed Date: 31 May 2025 at 6:21pm
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Topic: AC 715B backhoe question
Posted By: Reddog
Subject: AC 715B backhoe question
Date Posted: 18 Apr 2010 at 6:09pm
| Hello to all. New to the forum, but looks like you folks have a good bunch. I just bought a 715B backhoe and have a leaky swing cylinder. I thought I could take the ram apart from the back by removing the collar on the cylinder, but it appears that is not the case. Anybody had one of these apart and willing to give me a few tips on how to proceed. Thanks in advance, Doug at 8000' |
Replies:
Posted By: Coke-in-MN
Date Posted: 18 Apr 2010 at 7:14pm
|
The cylinder is trunion mounted , the pin is near center , it is not a ram but a double acting cylinder . Oil from one side (front) flows to the rear of other cylinder when swinging.
Disassembly is from front, the shaft side. ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: Reddog
Date Posted: 18 Apr 2010 at 7:34pm
| Coke, thanks for the response and the ram vs. cylinder clarification. I have the shaft disconnected from the hoe, and have removed the threaded ring that I had thought would let me remove the shaft assembly, but I'm now stumped on how to get the shaft out of the cylinder. Doug at 8000' |
Posted By: Coke-in-MN
Date Posted: 18 Apr 2010 at 8:56pm
|
If you have the gland removed the shaft should come out of cylinder.might be pull hard and it comes easily. Had to replace one shaft on my machine as it broke but beem a few years now and memory fades of all the procedure. ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: Reddog
Date Posted: 18 Apr 2010 at 9:16pm
| Gland nut is removed, but on this cyl it threads onto a "plug" that goes into the cyl itself. I can grab the exposed threaded portion if the "plug" and turn it, but it will not come out. It is as if the "plug" goes in from the opposite end and is resting on a shoulder, the nut then pulls it up tight against the shoulder. I'll try to post a picture tomorrow. It is unlike most other cylinders I have worked on. Thanks for the ongoing input. Doug at 8000' |
Posted By: Coke-in-MN
Date Posted: 19 Apr 2010 at 9:31am
|
threaded ring holds the top bearing (gland) this is a "O" ring seal to the cylinder bore. By pulling on shaft it should remove the piston, and gland. To remove this assembly the piston is removed from shaft and gland slid down shaft and off.
Inside gland is a set of "O" rings and backer ring. Piston is "O" ring and wear ring (bearing material ) which keeps piston itself from contacting bore of cylinder.
Should be a exclusion wiper (seal) in end of gland to keep dirt out of system. ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: Reddog
Date Posted: 19 Apr 2010 at 11:36am
| Coke, Thanks again. As it turns out, the "plug" pushes in, then you can access a snap ring, which when removed, allows the "plug" to come out and the shaft and piston assy to come out. Thanks again for the help. Doug at 8000' |
Posted By: Coke-in-MN
Date Posted: 19 Apr 2010 at 7:16pm
|
hmm , like i said memory fades as it has been couple years since, then only had to work on it once.
That and I was to lazy to walk out to shop , had not had 3rd cup of coffee so no ambition. ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: Reddog
Date Posted: 19 Apr 2010 at 7:44pm
|
Hey Coke, no worries. My standard line is "Well, Ive slept sine then". Never seen one come apart quite like this. Has a urethane inner seal, got a couple ordered, hopefully back together by the weekend. Overall, I'm pretty impressed with he old machine. I had a Cat 416 II a couple years ago and just sold a 97 Case 580 Super K. Both nice machines, but I had too much $$$ tied up in them to justify keeping them. This rig was just sitting and I hit the owner up to see if he would sell. After 5 months of sitting, it fired right up. Pins are tight, has a cab and heat, overall pretty nice. I like the Cat configured twin stick hoe, no relearning to do. It had been run without a cutting edge, so I've got a little welding to do, but the mornings are still cool here, so the heat is nice. Anyway, thanks again for the input. Happy Trails, Doug at 8000' |
Posted By: Calvin Schmidt
Date Posted: 20 Apr 2010 at 5:49am
| I've had a 715B for 23 years and it a very good machine. Can't help with the cylinder because I've never had one apart. Had a straight 715 for 10 years before the "B" and a I-60 for a few years before that. Allis-Chalmers backhoes since 1974. They were used to dig silo footings. the 715B has been retired to farm duty since we sold the farm silo business 15 years ago. Industrial silo foundations require excavators. |
Posted By: Coke-in-MN
Date Posted: 20 Apr 2010 at 6:15am
|
The machine still can do a good days work, used mine for 15 years putting in septic systems. I had a AC 615 detatchable hoe on my HD4 loader before the 715B.
Seems the only thing I have run is the 2 stick, changed hose position so machine is now same as CAT exc on the stick position.
Just used it to pick NH 781 skid steer off trailer, lifted it fine. ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: Reddog
Date Posted: 20 Apr 2010 at 7:12am
| The machine seems more than capable, and came with 2 hoe buckets. Pretty rocky here, so the narrow bucket is nice, a little sower, but less strain on the machine. My only real lament is the other rigs were 4x4. Really nice for snow, but I feel like if you can't get yourself un-stuck in a backhoe, maybe you should stick to a shovel... |
Posted By: Coke-in-MN
Date Posted: 24 Apr 2010 at 7:07pm
|
Used mine for snow work also and the hoe will get you out of most stuck places.
With the dif lock it moves fine in heavy snow, but i did break both loader arms in -20 F weather when I hit a large rock in church parking area. One side one week and the other the following week.
I have the dig-more extenda-hoe attachment so can dig to about 18' with dipper extended. Using a 34" bucket but have a 12" trenching bucket also. have a 24" bucket from AC 615 hoe but pin size is 1 1/4" instead of 1 1/2 like 715
------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: KRAKMT
Date Posted: 21 May 2010 at 3:51pm
|
Hey you 715B/D experts-
I acquired a 715 after a friends dad passed away. Engine is a new rebuild and I have gone through and changed most of the hoses, all the filters and fluids and added an aux hydro port.
But next will be to tackle the velvet shuttle shift- no go forward or back.
Can anyone give me the cliff note version on how these work? Do the electronics control any of the shuttle shift?
Also any resourse on determining age?
|
Posted By: Dave A
Date Posted: 22 May 2010 at 8:41am
hey if it is the same as the 816. can send pics of swing cylinder. have a repair manual for the 816. Here is the pic of the swing cylinder.
 ------------- Play the game for more than you can afford to lose... only then will you learn the game. Winston Churchill |
Posted By: Dave A
Date Posted: 22 May 2010 at 8:45am
|
the shuttle shift may just be a linkage. The nut came off mine last week. was a easy fix ------------- Play the game for more than you can afford to lose... only then will you learn the game. Winston Churchill |
Posted By: Coke-in-MN
Date Posted: 22 May 2010 at 8:53am
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It's a clutch pack that is hyd applied , all mechanical in that way. Torque converter ahead of it. Check fluid level Type A ATF ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: Dave A
Date Posted: 22 May 2010 at 10:21am
 ------------- Play the game for more than you can afford to lose... only then will you learn the game. Winston Churchill |
Posted By: Dave A
Date Posted: 22 May 2010 at 10:23am
|
hope this helps. The info is from a 816B. I think they use the same primary drive parts ------------- Play the game for more than you can afford to lose... only then will you learn the game. Winston Churchill |
Posted By: KRAKMT
Date Posted: 22 May 2010 at 8:27pm
|
Thanks guys for all the help. I think it is different than the 816. If I can figure out how to resize a photo I will post a couple or start a new thread. I did drain and replace the fluids in the shuttle shift and new filter then left it run for 20 minutes and still no go. I did notice the clutch linkage looks to be sliding above the shaft(same shaft that is turned by the f/r shuttle control. I assume when clutched the shaft slides in or out of the housing? I also notice a couple wires hanging down- not plugged in. Anything electrical in a shuttle shift? My buddies dad was a heavy equipment collector and had 15 acres in varying states of disrepair. I didn't pay a lot for it but it is a nice hobby/restore. |
Posted By: Coke-in-MN
Date Posted: 23 May 2010 at 9:50am
|
nothing electrical in unit, switch or wires for back up alarm .
info on the 816 should also be close to 715 unit, test the pressures. Clutch packs are a wear item and do go bad , R & R for 715 is 15 hours. ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: Dave A
Date Posted: 23 May 2010 at 10:05am
|
would almost think it is a tourq converter. If both forward and reverse is not working ------------- Play the game for more than you can afford to lose... only then will you learn the game. Winston Churchill |
Posted By: KRAKMT
Date Posted: 24 May 2010 at 1:31pm
|
Before I can tear apart the trans I need to put back together the hydraulics. Any suggestions on Hydraulic fluid? K |
Posted By: Reddog
Date Posted: 30 May 2010 at 5:42pm
| Weight?? Anybody got a good, educated guess on what a 715B with cab, no extrndahoe, no liquid in the tires might weigh?? Thanks, Doug at 8000' |
Posted By: Coke-in-MN
Date Posted: 30 May 2010 at 5:48pm
|
Hyd fluid would be Universal tractor hyd , or 10/30 motor oil
Weight should be around 15,000.
If it has extenda-hoe they advise adding 500# to fron of machine ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |