I just purchased a 89 Bobcat 743 and the lift arms drop pretty quick. If I have the bucket tilted and shut the machine off while in the air the arms still lower. Once they bucket touches the ground the front tires will slowly lift off the ground ( 2-4 minutes with machine not running ). What are the most possible causes? ---- I did get a service manual for a 641, 642, 643 with this machine. Is this service manual similar to the one I should have for the 743? Or would it be wise to go ahead and purchase one for the 743? I plan on having this machine for a long time. I think having a repair / service manual is good to have on hand. I have them for most everything I own. ---- It started up fairly easy and seems to have 5 times more power than a 1975 700 series Bobcat a friend and me own ( that thing is about to get some needed updates as well ). I needed / wanted one for another property I have. This is the first diesel I have ever owned and I am liking it so far. ------ What I have done so far: Fixed 1 tire and have another with a slow leak ( 4-5 days till flat ). I have tilted the cab and power washed a lot of the crud out, but have some more to go. Replaced the primer bulb for the fuel line ( old one was cracked and leaking ). In the next couple days I plan on getting to the universal joints and checking / greasing them ( read about those in another thread ). What other things should I check or change before using this machine 2-4 times a week? ------ Machine history: This machine sat for at least 4 years without being moved ( purchased from a family member ). He made a backhoe digger arm. It doesn't move side to side, ( you have to turn the machine to go side to side ) but worked for it's purpose and was used quite a bit years ago. Thanks in advance
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The 6 series manual will be close to your 743, not the same but pretty close.
As for the lift arm drop, start with re-packing the cylinders. The piston seals do go bad over time and can cause the arms to drop like this. It's normal for the front wheels to come off the ground like this as they lower. If it still does it after doing the cylinders, check your load checks in the control valve, but this is a last resort, as it's a little harder to access.
the 743 series were good machines, a little less power than the newer ones, but no electronics.
As for the lift arm drop, start with re-packing the cylinders. The piston seals do go bad over time and can cause the arms to drop like this. It's normal for the front wheels to come off the ground like this as they lower. If it still does it after doing the cylinders, check your load checks in the control valve, but this is a last resort, as it's a little harder to access.
the 743 series were good machines, a little less power than the newer ones, but no electronics.
Thanks for the reply Tazza I have rebuild kits ordered and will try this first. Hoping it takes care of this issue. HowdyThe 6 series manual will be close to your 743, not the same but pretty close.
As for the lift arm drop, start with re-packing the cylinders. The piston seals do go bad over time and can cause the arms to drop like this. It's normal for the front wheels to come off the ground like this as they lower. If it still does it after doing the cylinders, check your load checks in the control valve, but this is a last resort, as it's a little harder to access.
the 743 series were good machines, a little less power than the newer ones, but no electronics.
Rebuilt the lift cylinders and still have the drifting issues. It did slow it down slightly but that's about it. At least I know the cylinders should be good for some time. HowdyThanks for the reply Tazza I have rebuild kits ordered and will try this first. Hoping it takes care of this issue. Howdy
The next point that can cause leakage is the load checks in the control block.Rebuilt the lift cylinders and still have the drifting issues. It did slow it down slightly but that's about it. At least I know the cylinders should be good for some time. Howdy
Looking where each tube line attaches, there will be a plug or relief valve screwed in. The seats could be worn or with the relief valves, the Orings can leak. It is a possible point of internal leakage.
Sorry for the delay, How ever I want to say Thanks Tazza!!! A little update: I did order a rebuild kit. But while waiting on parts life got in the way and I was forced to put repairing this on the backburner. I started tearing into it yesterday and have found more issues that need fixing as well. Couple hoses with enough wear that I decided to replace ( preventive ). I also found a small leak on a hose fitting that feeds the pump. It's probably original and will be replaced just incase. I also found a very bad battery cable ( very corroded and started smoking ) while starting. New cable will installed. I am not rushing this project at all right now. I'm going to try and inspect every thing I can and repair as needed. My thoughts are if I fix everything that I find wrong now this machine should provide me with good dependability for a few years. I can hope anyway. LOL I will provide updates as I progress with the project. HowdyThe next point that can cause leakage is the load checks in the control block.
Looking where each tube line attaches, there will be a plug or relief valve screwed in. The seats could be worn or with the relief valves, the Orings can leak. It is a possible point of internal leakage.
They are a good machine, being that age, hoses will start to leak, you are doing the right thing replacing them as they start to go.Sorry for the delay, How ever I want to say Thanks Tazza!!! A little update: I did order a rebuild kit. But while waiting on parts life got in the way and I was forced to put repairing this on the backburner. I started tearing into it yesterday and have found more issues that need fixing as well. Couple hoses with enough wear that I decided to replace ( preventive ). I also found a small leak on a hose fitting that feeds the pump. It's probably original and will be replaced just incase. I also found a very bad battery cable ( very corroded and started smoking ) while starting. New cable will installed. I am not rushing this project at all right now. I'm going to try and inspect every thing I can and repair as needed. My thoughts are if I fix everything that I find wrong now this machine should provide me with good dependability for a few years. I can hope anyway. LOL I will provide updates as I progress with the project. Howdy
2 hoses replaced and manifold rebuilt and installed. Started the skid and worked the air out of the system. Raised the lift arms 3 ft and left it sit over night. This morning the arms had only dropped 1 1/2". I am VERY happy. Started working on the lights and got them working. The ones that were on it aren't bright enough for my liking. I have some small LED lights and 1 of them was 5 times brighter than the one on it. I went overkill and added 4 of the LED lights. This will come very handy this weekend when the skid gets put into heavy use ( anticipated heavy snow removal ). I have 6 people that depend on me to dig them out of the snow ( some 37 miles away ). I never have charged a dime to these people as I enjoy helping others and playing in the snow. Tomorrow will be getting the snow blade ready and staged to have fun. HowdyThey are a good machine, being that age, hoses will start to leak, you are doing the right thing replacing them as they start to go.
Glad you got it all fixed.2 hoses replaced and manifold rebuilt and installed. Started the skid and worked the air out of the system. Raised the lift arms 3 ft and left it sit over night. This morning the arms had only dropped 1 1/2". I am VERY happy. Started working on the lights and got them working. The ones that were on it aren't bright enough for my liking. I have some small LED lights and 1 of them was 5 times brighter than the one on it. I went overkill and added 4 of the LED lights. This will come very handy this weekend when the skid gets put into heavy use ( anticipated heavy snow removal ). I have 6 people that depend on me to dig them out of the snow ( some 37 miles away ). I never have charged a dime to these people as I enjoy helping others and playing in the snow. Tomorrow will be getting the snow blade ready and staged to have fun. Howdy
I didn't find the lights to be too bad, but LED ones would have given far better light.
I have discovered an architectural bulb that is LED and fits old bobcats directly. $10-12 US and isn't subject to the filament breakage like the originals. Decent flood pattern, 2-minute install.Glad you got it all fixed.
I didn't find the lights to be too bad, but LED ones would have given far better light.
Sounds interesting, do you have a link to this replacement bulb at all?I have discovered an architectural bulb that is LED and fits old bobcats directly. $10-12 US and isn't subject to the filament breakage like the originals. Decent flood pattern, 2-minute install.
This might be a good LED replacement link but I'm cheap, I bought a case of 50W halogens for about $2.50 each, that is probably a lifetime supply for me.Sounds interesting, do you have a link to this replacement bulb at all?
