Hi all, just wanted to introduce myself as a long time bobcat 720 owner. I purchased my 720 many years ago, it was my first piece of heavy equipment and the beginning of a successful excavation company which I've owned and operated for many years. The 720 was mainly used as a wheel barrow to move massive quantities of gravel and dirt in and out of many inner city job sites. It's compact size and light weight was a clear advantage in many situations. Although I've replaced the 720 with modern equipment t and my business has grown, I still have the machine which has retired on my cottage property. Because it was my first machine and although it has its issues, I cannot say goodbye. There's so much emotion and memory wrapped up in that little beast. I joined this forum in the hope that folks here might help me get it back up and running and to continue being of use on a rural property. In fact, it runs like a top and the bucket tilt and lift is fully operational but the final drives on each side are non responsive. With your help I can keep this machine and the memories it evokes, alive. Thank you.
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Welcome to the forum. I am also the proud long term owner of a 720, but I bought mine with the Wisconson engine in a basket. I swapped in a 1600 engine from a 67 Ford Cortina, and have been using this combination since 1985.
Your final drive problem could be a serious issue, but it could also be as simple as contamination of your main hydraulic, or your bypass filter. It would be a prudent first step, to change both the filters, and cut them open for evidence of metal particles or contamination.
There are links on the forum to the shop service manual, and if you are going to work on the Bobcat yourself, it will be a necessary place to start, so that you understand how the hydraulic system works.
The fact that the lift and tilt are working, indicates that the problem is isolated to the drive system. If it is necessary to repair, or overhaul the the motor pumps, it is not that difficult, but you need to have a clean area to work. When I bought my machine, my pumps were in pieces, and I rebuilt the high pressure pump, the drive pump, and the motor pumps in my basement. The next thing, is before you start disassembling the machine, give it a thorough cleaning with a high pressure washer or steam cleaner. You will thank me later.
In short, it will not be that difficult to get your machine running again, so you can enjoy many more years of use with it. If you have a problem finding the Bobcat manuals for the 720, PM me, and I will forward them to you.
Good luck with getting it working again.
Bob
Your final drive problem could be a serious issue, but it could also be as simple as contamination of your main hydraulic, or your bypass filter. It would be a prudent first step, to change both the filters, and cut them open for evidence of metal particles or contamination.
There are links on the forum to the shop service manual, and if you are going to work on the Bobcat yourself, it will be a necessary place to start, so that you understand how the hydraulic system works.
The fact that the lift and tilt are working, indicates that the problem is isolated to the drive system. If it is necessary to repair, or overhaul the the motor pumps, it is not that difficult, but you need to have a clean area to work. When I bought my machine, my pumps were in pieces, and I rebuilt the high pressure pump, the drive pump, and the motor pumps in my basement. The next thing, is before you start disassembling the machine, give it a thorough cleaning with a high pressure washer or steam cleaner. You will thank me later.
In short, it will not be that difficult to get your machine running again, so you can enjoy many more years of use with it. If you have a problem finding the Bobcat manuals for the 720, PM me, and I will forward them to you.
Good luck with getting it working again.
Bob
Welcome to the forum. I am also the proud long term owner of a 720, but I bought mine with the Wisconson engine in a basket. I swapped in a 1600 engine from a 67 Ford Cortina, and have been using this combination since 1985.
Your final drive problem could be a serious issue, but it could also be as simple as contamination of your main hydraulic, or your bypass filter. It would be a prudent first step, to change both the filters, and cut them open for evidence of metal particles or contamination.
There are links on the forum to the shop service manual, and if you are going to work on the Bobcat yourself, it will be a necessary place to start, so that you understand how the hydraulic system works.
The fact that the lift and tilt are working, indicates that the problem is isolated to the drive system. If it is necessary to repair, or overhaul the the motor pumps, it is not that difficult, but you need to have a clean area to work. When I bought my machine, my pumps were in pieces, and I rebuilt the high pressure pump, the drive pump, and the motor pumps in my basement. The next thing, is before you start disassembling the machine, give it a thorough cleaning with a high pressure washer or steam cleaner. You will thank me later.
In short, it will not be that difficult to get your machine running again, so you can enjoy many more years of use with it. If you have a problem finding the Bobcat manuals for the 720, PM me, and I will forward them to you.
Good luck with getting it working again.
Bob
Hi Bob, thanks for your response. I removed the 10 micron bypass filter and it looked ugly. The hydraulic fluid was a milky white with dirty bits (fine) and a lot of water. I've ordered new filters and am thinking of dumping all the hydraulic fluid and adding all new. Any advice on how to best drain as much as the ugly as possible? I presume there will be remnant fluid in the cylinders and the pump body and final drives. I see the tank and the small drain port at the bottom on the left hand side of the machine (port side). I drained it once many years ago from this location. What do you think?
My suggestion when changing the hyd. oil is to buy lots of it, it's not a one time thing does it all. Yes you will still have contaminated oil in the crooks & crannys & the cylinders & pumps. I changed mine, in a T300, last winter when I resealed all the cylinders & made new pins as it was inside the cylinders that I found "fines". I was worried that there may be "fines" in the reservoir also but I was able to rig a rare earth magnet on a stiff wire & worked a couple hours to get that cleaned. The reservoir is plastic with steel fittings imbedded to screw the hyd. lines into. I was able to "stick" the magnet with the wire attached to the return line to the tank & after using the machine for a day, I pull the magnet & check for "fines". So far with about 50 hrs. on the machine since the work was done & has come up clean. I just leave the magnet in the reservoir as it works for me!
After I bought my machine, I also had a problem with water in the hydraulic system, and it took more than one change of fluid and filters, to get the water out of the system.
I found that the water was getting in through the seams at the top of two large side access plates on the chassis. I had to pull them both, straighten the flanges, and re-seal the tops, before I was able to solve the problem of water getting in at the top of the plates..
The water didn't do any observable damage to my system, and any repairs to the system, such as overhauling cylinders in later years, was just a matter of wear and tear. There was no observable water damage.
I really feel that the 10 micron bypass filter was the lifesaver. because at the first sign of the controls not responding properly, every time I pulled that filter, it was loaded with water.
My only complaint was, that the location of the filter, didn't make it easy to do the change, but I found that the purchase of a filter wrench large enough to fit the larger diameter of the filter case, and a very long 1/2 extension, solved the problem of removing the filter.
Bob
I found that the water was getting in through the seams at the top of two large side access plates on the chassis. I had to pull them both, straighten the flanges, and re-seal the tops, before I was able to solve the problem of water getting in at the top of the plates..
The water didn't do any observable damage to my system, and any repairs to the system, such as overhauling cylinders in later years, was just a matter of wear and tear. There was no observable water damage.
I really feel that the 10 micron bypass filter was the lifesaver. because at the first sign of the controls not responding properly, every time I pulled that filter, it was loaded with water.
My only complaint was, that the location of the filter, didn't make it easy to do the change, but I found that the purchase of a filter wrench large enough to fit the larger diameter of the filter case, and a very long 1/2 extension, solved the problem of removing the filter.
Bob
Hello fellow 720 owner I have a question what year is it ? Bobcat told me they only made that model for 2 years. I like mine but I am having trouble finding parts Bobcat discontinued making parts. I just blew the main hydraulic pump and was hoping maybe you could help me with some suggestions.Hi all, just wanted to introduce myself as a long time bobcat 720 owner. I purchased my 720 many years ago, it was my first piece of heavy equipment and the beginning of a successful excavation company which I've owned and operated for many years. The 720 was mainly used as a wheel barrow to move massive quantities of gravel and dirt in and out of many inner city job sites. It's compact size and light weight was a clear advantage in many situations. Although I've replaced the 720 with modern equipment t and my business has grown, I still have the machine which has retired on my cottage property. Because it was my first machine and although it has its issues, I cannot say goodbye. There's so much emotion and memory wrapped up in that little beast. I joined this forum in the hope that folks here might help me get it back up and running and to continue being of use on a rural property. In fact, it runs like a top and the bucket tilt and lift is fully operational but the final drives on each side are non responsive. With your help I can keep this machine and the memories it evokes, alive. Thank you.
I think mine is a 1979 but not sure here is the serial # maybe this can help 4957M14817Hello fellow 720 owner I have a question what year is it ? Bobcat told me they only made that model for 2 years. I like mine but I am having trouble finding parts Bobcat discontinued making parts. I just blew the main hydraulic pump and was hoping maybe you could help me with some suggestions.
Hey Bob, I have a 720 and can't find any shop manuals or part numbers for this machine. If you could forward a copy of what you have I would greatly appreciate it.Welcome to the forum. I am also the proud long term owner of a 720, but I bought mine with the Wisconson engine in a basket. I swapped in a 1600 engine from a 67 Ford Cortina, and have been using this combination since 1985.
Your final drive problem could be a serious issue, but it could also be as simple as contamination of your main hydraulic, or your bypass filter. It would be a prudent first step, to change both the filters, and cut them open for evidence of metal particles or contamination.
There are links on the forum to the shop service manual, and if you are going to work on the Bobcat yourself, it will be a necessary place to start, so that you understand how the hydraulic system works.
The fact that the lift and tilt are working, indicates that the problem is isolated to the drive system. If it is necessary to repair, or overhaul the the motor pumps, it is not that difficult, but you need to have a clean area to work. When I bought my machine, my pumps were in pieces, and I rebuilt the high pressure pump, the drive pump, and the motor pumps in my basement. The next thing, is before you start disassembling the machine, give it a thorough cleaning with a high pressure washer or steam cleaner. You will thank me later.
In short, it will not be that difficult to get your machine running again, so you can enjoy many more years of use with it. If you have a problem finding the Bobcat manuals for the 720, PM me, and I will forward them to you.
Good luck with getting it working again.
Bob
The serial number of my machine, is 14212, and came originally with the Wisconson Engine. The engine was destroyed, and back in 1983, just the cost of the crank was $1500.00, so I swapped in the engine from a 1967 Ford Cortina. The most difficult task, was setting up a governor from scratch without any documentation.I think mine is a 1979 but not sure here is the serial # maybe this can help 4957M14817
I need wheel seals and bearings, and have not been able to find a source either.