Lift Arms leak down

[kensteer]

When I raise the bucket all the way up and leave it in this position, over a period of several minutes, it will come down, all though gradually. The tilt cylinder may stay in position for day; if I have the bucket down and curled so that the front tires are up off the ground. It does have new seals in it. The lift cylinders don't show any external hydraulic fluid leaks. Another thing is the machine won't lift a loaded pallet weighing one ton.

 

[mrbb]

you might want to add more info, like what exact model machine this is, as without knowing what model it is, we have no way of knowing what its actual lift capacity is,
it might just not be a strong enough machine to lift a ton, making it perfectly normal for it not too

and as for things bleeding down over time, ALL machines will do so, its also perfectly normal for them to do so, BUT how fast they bleed down, might mean an issue or not
and you do know(no bash here meant) that your not supposed to exit a machine with the bucket all the way up, and the reason is, things can fail and that bucket and arms can come crashing down and KILL you!

 

[kensteer]

743

 

[mrbb]

OK so according to BOBCAT< and see link below)
the spec's on your machine say it was designed to only lift 1300 lbs, so asking it to lift 2000 lbs is, going beyond what it was designed to do

SO?? that sort of answers your one question as to why it won't lift a Ton!, which is 700 lbs past what it was designed to lift!

next, as for your leak down, remember this is a machine that is 30+ yrs old, ((made from 1980' to 1990) so, age , has a way of effecting systems and cause faster leak downs than when new, which IMO< explains the other question you have! it just older and things ain;t working as they did when new, but even NEW all systems will again leak down , they were not designed with sets to prevent that from happening over time they will slowly bled down, a very FAST bleed own could me something is wore beyond spec, and be a cause, but its normal IMO< for older machines to bleed down fairly fast , as in a few hours or so, some do so even faster ,

Others may have other info or thoughts or idea's to add, but that is my take on things, hope it helps>

and here is a link to spec's on your machine for you to see things

https://www.bobcat.com/na/en/equipment/loaders/skid-steer-loaders/non-current-models/743

 

[laurencen]

we have a 743, correct it will not lift 2200lbs, its capacity is 1300lbs, mine is hard pushed to lift 1000lbs and the cylinders will leak down slowly, just leaving the arms up 2 inches and bucket curled next day bucket is flat on the ground

if the arms of fully up and in a couple mins they are down I suspect the valve is leaking, for such a short time I would think you could hear the oil bypassing the valve, also if its that quick I would sugest you not come out the cab, leaking that bad you could get badly hurt

what will it lift? maybe the relief is set too low

 

[Markle]

Probably some minor leak inside the valve spool. I didn't think the relief was adjustable on my 743 with Gresen spools. I'm thinking could also be minor bypass within lift cylinders past piston. It could do this without external leak. I'm not worried if about an inch drop per hour. if faster, and or unsafe, further investigation may be advisable.

 

[kensteer]

Here is a picture of the back of the Alternator. Two red wires and a green wire. The green wire is the exciter wire. I was told to run that wire to a bulb.

 

[cdmccul]

Looks like your middle nut there may be loose, the heavy red wire with the yellow collar on the crimp.

The reason I say, is that the stranded wire is kinda under the nut. This will make it go "tight" while you are there, but after some wiggling and vibrating, will come loose.

This can blow out voltage regulators, btw. In the marine industry, this has caused compete boat fires and total losses.

Also double check that your ring terminal(s) isn't grounding out on the alternator case.

 

[Equipment_Tech]

When I raise the bucket all the way up and leave it in this position, over a period of several minutes, it will come down, all though gradually. The tilt cylinder may stay in position for day; if I have the bucket down and curled so that the front tires are up off the ground. It does have new seals in it. The lift cylinders don't show any external hydraulic fluid leaks. Another thing is the machine won't lift a loaded pallet weighing one ton.

Weight capacity is definitely your main cause when over loading it weakens the spring on your pressure relief valve casing it to bleed out and loose pressure

You should have 2 identical relief valves 1 for you lift and 1 for your curl

Simply swap the 2 relief valves around do not adjust them this will confirm that you need a new relief valve

Hope that helps you out