I tried to work out the hydraulic issue this weekend. I raised and lowered the booms, and moved the bucket up and down. The bucket didn't make as much noises unless you used it to raise the machine off the ground (under load). The booms made a heck of a racket even shook the machine. Probably raised it up 5 or 6 times, I did this at idle as it was much worse at full throttle. Is there a better way to bleed the system. Still has the same problems, could it be anything else? Thanks for your inputs/suggestions.
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What are you using for "hydraulic oil"? The 743, 742, 741 machines were designed to use motor oil in the hydraulic system.
Your best bet is to run it for a few minutes, drive it around alittle then let it sit a few hours, repeat till you get most of the air out.
Bobcat brand hydraulic oil, I bought the oil from Bobcat.
Possibly bad coupler between motor and pumps?
it drives fine no noises just goes, but the bucket and boom action shake and rattle. doesn't seem to have much lift ability. So that is why I am confused. If the system has air in it wouldn't that affect the hydrostat? Thanks for your advise.
the problem will be most noticeable in the hydro circuit that the air is trapped , hydro oil will not compress making smooth operation is system with no air ,, air will compress causing erratic operation. remember each movement is operated by a valve if you are sitting still and operate the bucket the air in the bucket circuit is turned off from the forward reverse circuit to feel it in the movement circuit you would have to be moving and operate the bucket at the same time. but it will not be as noticeable in the sections with no air. see clear as mud.
Ensure the aux hydraulics are not stuck on. Grab the right stick, pull it to the left and let it spring back to neutral. If the aux was stuck on, it will mess with the lift/tilt functions but not cause any issues with drive.
I like the thread! Good information on things that could happen with a new (to you) piece of equipment. Keep us posted on the progression. I have been working on an 843. It arrived dead. I'm sure I will encounter many of the same issues. I currently have the motor removed and I am rebuilding the u-joint pump coupling. My unit had mountains of goo inside the engine bay. I started using Simple Green cleaner and it works great for removing grease and oil. I plan to repaint the engine bay white. I think it will help identify any leak sources. If anyone is interested I have a YouTube channel I can share. I am documenting the repair of this unit. New videos every Wednesday. Thanks
Thanks Tazza. I went and tried that, the stick wouldn't move. Then my wife reminded me that the guy we bought it from left the bolt in it since he didn't plan on using the aux hyd. I videoed the noise it makes, now I have to figure out how to put it on here. Thanks for your help.
If it was locked with a bolt, the aux was not stuck on....
If you upload the video to youtube, you can share a link.
I showed my video to a bobcat dealer, he thinks it is the relief valve. he says if it hadn't moved for a while it may have broke the pin or spring??? So I will look into that.
Has anybody had a problem with the bolt that connects the solenoid to the starter (brass bar) coming loose. I had tightened it before, but over the weekend every time I got in it to start it you would get a click from the key, then take an 8mm socket tighten that bolt then start it. You were good till you shut it off again. I am thinking locktite, anybody else?
flyerdan
Well-known member
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- Mar 7, 2009
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It probably had a lock washer on it at one time, I'd try that, or a star washer first. Loctite on small electrical connections can cause problems later on when disassembling them.
I have yet to figure out the noise when I raise the booms. I now have another question. I was using it the other day to try and dig a hole. The ground was hard and dry. I did get it to dig in finally. Now when I drive it from point a to b it gets to lurching or hopping then starts to buck. So I come to a complete stop and start over. Is there one pump that provides oil to the hydro and the cylinder, or are there two pumps. Thank you.
Worn steering linkages are the main cause of this, chek that they are tight and the bushings are not worn.
Your drive pump is two pumps back to back, your lift/tilt is a seperate pump.
Thank you, I will check the linkages!
next question. When I got my 743 back from the dealer, I had them fix the left front wheel leak. They claimed it was a tough fight, then they torched the old bearing out. Ever since then, I add oil to the chain case and within a week it is all drained out. It appears to be leaking on the left side where the rectangle shaped chain case has what looks like a saddle bag on the side of it. I think I need to get a pan that will fit under it so I can reuse the oil that drips out. Is there a seal there? Thanks
Are you talking about the reduction box that the drive motor attaches to?
Worst case, look up my profile for my email address and send me a picture.
There is no reason for it to leak that much...... Axle seals can leak, bu as the dealer did the job, it should not leak anymore.
Tazza, I sent you and email with the picture. any advise is greatly appreciated. thanks
I am wanting to get a hoe attachment for my bobcat. I have seen several designs on you tube. I also have seen the Jensen model, which looks too heavy for my little 743 to even pick up. I like the design of the Texas skidsteer.com hoe seen on you tube. However, Texasskidsteer.com does not return phone calls. If someone has one for sale or if they have plans for one, I would be interested. Thanks.
