743

[bob@hyd]

Hi to all, I'm new to this forum, I've been reading it for a little while now and find it to be a good place for information. Now, for my question. I just purchased a 743. Mid 80's. 3400 hours on it. It runs great. All seems to work good. A couple loose joints, but I'm only going to be using it around the house. The problem I'm having is that when I drive it, it gets into this bucking mode that's almost impossible to stop. Forward and backward like a bronco. I've driven twin sticks before, I have a comercial lawn mower, same idea. I've tried to use a feather light touch on the sticks, but wants to start bucking. Is there a Damper for the hydrolics? Also, all the hydrolics seem real touchy. Foot controls are also very hard to do in a smooth motion. Even the auxilery grapplers are so quick that it's almost impossibe to move them in an easy maner. Is it me just getting used to the machine? Or is there some way to "tone down the hydrolics? Or to dampen them? Any info would be great. Bob

 

[Mr Jimi]

Welcome to the forum Bob, is your engine speed high? try it at a lower RPM and are your tires the same size and properly inflated to same pressure all around.
Thats about all I can think of
Jim

 

[bob@hyd]

Welcome to the forum Bob, is your engine speed high? try it at a lower RPM and are your tires the same size and properly inflated to same pressure all around.
Thats about all I can think of
Jim

Hi Jim, I've tried many different rpm's. Doesn't seem to change anything. Also checked the tire pressue. Put them all up to spec's. One thing that I've noticed, is when I'm running it the hydrolics don't make an even whine. They sound like they get into a surging mode and that's when the trouble starts. The whine gets loud/soft, loud/soft and so on. Then it starts to buck forward and back. Tough to stop it. From the whine in the hydrolics I'm wondering if the fluid is low? I'll be checking it tomorrow. It had a leak on the grappler ram. I've fixed it but haven't checked the fluid. Don't know how to check it. Haven't found a dipstick or a sight area. Thought I'd just start putting fluid in and see if that helps. Any ideas on if low fluid can cause problems like this? Like I said even the pedals are touchy. Thanks, Bob

 

[Mr Jimi]

Hi Jim, I've tried many different rpm's. Doesn't seem to change anything. Also checked the tire pressue. Put them all up to spec's. One thing that I've noticed, is when I'm running it the hydrolics don't make an even whine. They sound like they get into a surging mode and that's when the trouble starts. The whine gets loud/soft, loud/soft and so on. Then it starts to buck forward and back. Tough to stop it. From the whine in the hydrolics I'm wondering if the fluid is low? I'll be checking it tomorrow. It had a leak on the grappler ram. I've fixed it but haven't checked the fluid. Don't know how to check it. Haven't found a dipstick or a sight area. Thought I'd just start putting fluid in and see if that helps. Any ideas on if low fluid can cause problems like this? Like I said even the pedals are touchy. Thanks, Bob

I have a Case 1845 C, older machine. My hydraulic fluid check is a sight glass in the engine compartment, when I open rear door its on the far right and I have a leak in mine that I can't find, low fluid will cause weird things. Think about this, low on fluid will have some air in line and will work with fluid and not when air bubble is present.
Wish I could help ya more
Jim

 

[Tazza]

I have a Case 1845 C, older machine. My hydraulic fluid check is a sight glass in the engine compartment, when I open rear door its on the far right and I have a leak in mine that I can't find, low fluid will cause weird things. Think about this, low on fluid will have some air in line and will work with fluid and not when air bubble is present.
Wish I could help ya more
Jim

You should have a sight glass (or dip stick on the older model 743's) on the left hand side when sitting inside the machine.
Usually low oil will make things jerky and the machine will make a howling noise. Hydraulic operation will be all jittery. There are no buffers for the controls either.
You may want to replace your hydro filter if you haven't already done so.
When you lift the cab, do you see a block on top of the hydraulic pump with 4 or 5 hoses going into it? or do you see a large hose (about 1 1/2" diameter) from the left that joins to the hydraulic pump? The one with the block has a hidden filter that can cause issues.
Start with the simple things and see how you go.

 

[bob@hyd]

You should have a sight glass (or dip stick on the older model 743's) on the left hand side when sitting inside the machine.
Usually low oil will make things jerky and the machine will make a howling noise. Hydraulic operation will be all jittery. There are no buffers for the controls either.
You may want to replace your hydro filter if you haven't already done so.
When you lift the cab, do you see a block on top of the hydraulic pump with 4 or 5 hoses going into it? or do you see a large hose (about 1 1/2" diameter) from the left that joins to the hydraulic pump? The one with the block has a hidden filter that can cause issues.
Start with the simple things and see how you go.

Thanks to all for the info. I finally had a chance to put in hyd. oil. That seems to have made the bucket easier to control. Not quite as touchy. As for the steering, I'm not sure. When I go backward I don't seem to have much noise from the hyd. motors, as in not much whinning. But forward seems to be a different story. I'm very new to a skid steer, a few days, so not really sure what is normal and whats not. When I turn, one forward and one back, the machine tends to hop. This is whether on dirt, grass or gravel. It's not to bad though. But I do get quite abit of whine. It seems if I use a very light touch on the sticks, it works better. But if I make a sudden stop, it will start rocking and that's when I've got to be real careful or it will start bucking. I've tried to just let go of the sticks, but they don't come to center from the forward position. When it's starts rocking it's very hard to pull the sticks gently. I've put the tires up to the proper pressure. And all seems good there. Must say about the machine. I bought it from a construction company that was selling his "excess" equiptment. I tend to think that he buys them, puts a quick coat of paint on them and then sells them. He worked it while I watched, all seemed ok. But he gave me alot of miss info. I checked it over and didn't see any extra welds, engine runs good, not much for leaks, over all sounds and looks pretty good. So, anyway, let me know if it sounds like I just need more practice driving. Or if there is something more I should check, let me know. I plan on changing filters and checking the screen that Tazza mentioned, but come Monday I'm going to the dealer and buy a service manual and some other small parts that I need.
Thanks for any info.
Bob

 

[bob@hyd]

Thanks to all for the info. I finally had a chance to put in hyd. oil. That seems to have made the bucket easier to control. Not quite as touchy. As for the steering, I'm not sure. When I go backward I don't seem to have much noise from the hyd. motors, as in not much whinning. But forward seems to be a different story. I'm very new to a skid steer, a few days, so not really sure what is normal and whats not. When I turn, one forward and one back, the machine tends to hop. This is whether on dirt, grass or gravel. It's not to bad though. But I do get quite abit of whine. It seems if I use a very light touch on the sticks, it works better. But if I make a sudden stop, it will start rocking and that's when I've got to be real careful or it will start bucking. I've tried to just let go of the sticks, but they don't come to center from the forward position. When it's starts rocking it's very hard to pull the sticks gently. I've put the tires up to the proper pressure. And all seems good there. Must say about the machine. I bought it from a construction company that was selling his "excess" equiptment. I tend to think that he buys them, puts a quick coat of paint on them and then sells them. He worked it while I watched, all seemed ok. But he gave me alot of miss info. I checked it over and didn't see any extra welds, engine runs good, not much for leaks, over all sounds and looks pretty good. So, anyway, let me know if it sounds like I just need more practice driving. Or if there is something more I should check, let me know. I plan on changing filters and checking the screen that Tazza mentioned, but come Monday I'm going to the dealer and buy a service manual and some other small parts that I need.
Thanks for any info.
Bob

Had a chance to drive the 743. Found it seems to buck less at full throttle. But still will start bucking if not careful. Do the hydrolic motors turn gearboxes that drive chain to the wheels? I think I've seen some pictures on this forum that look that way. If so, having loose chains might be the slop in my drivetrain that allows the maching to start bucking? Would there be a way to tighten up the chains? If this is the case that might be what I need to look for.
Bob

 

[Tazza]

Had a chance to drive the 743. Found it seems to buck less at full throttle. But still will start bucking if not careful. Do the hydrolic motors turn gearboxes that drive chain to the wheels? I think I've seen some pictures on this forum that look that way. If so, having loose chains might be the slop in my drivetrain that allows the maching to start bucking? Would there be a way to tighten up the chains? If this is the case that might be what I need to look for.
Bob

There is no chain adjustment.
The hydro motors do indeed run into a gear box to reduce the speed.
As for bucking while turning, this is normal if you turn quickly. The whining could be because there is still air in your system. Does the hydraulics move smoothly or does it jitter a bit? Running at full or near full throttle will make it whine less, it does this for me too.
Try and be gentle with the levers till you get used to it, don't just let them go as when the machine bucks it will throw the levers around too. You will get the hang of it soon enough.
As for a service manual, you are really better off getting one off e-bay, the dealer will want a kidney, or 2 for a maual. I got mine off a guy that goes by the name maxxwedge on e-bay, he was very helpfull. Check what the dealer wants for one, then check e-bay, the price from the dealer may actually be reasonable.

 

[JD4440]

Loader here has the same condition supposedly. It has a flat currently that makes it hard to get an accurate view on the sight glass; looks really low. I'll change the oil/filter and clean the screen ( I suppose it's serviceable instead of having to buy a new one?) and post my results. (yes I know this is really old)

 

[BobCat]

Had a 720 series that bucked allot. When it got bad I'd just let the levers go allowing it to go into neutral. Then easy back into it. Now I'm not saying just let go of the levers if you know what I mean. After x number of hours of operating your new toy you'll get the hang of it. Enjoy!

 

[Tazza]

Had a 720 series that bucked allot. When it got bad I'd just let the levers go allowing it to go into neutral. Then easy back into it. Now I'm not saying just let go of the levers if you know what I mean. After x number of hours of operating your new toy you'll get the hang of it. Enjoy!

Generally the site glass can be cleaned.

 

[JD4440]

Generally the site glass can be cleaned.

glass is good and clean but the way the loader is sitting it looks to be low. I'm thinking/ hoping the level will come back up when it's on all 4's again

 

[JD4440]

glass is good and clean but the way the loader is sitting it looks to be low. I'm thinking/ hoping the level will come back up when it's on all 4's again

it was 2 gal low