boom trouble with hyundai 290

just did a complete seal change on the main control valve of my hyundai 290 NLC-7, all went well apart from boom down function.
it works but has lost power and if you boom down doesnt lift the machine off the ground.
but if i do the same with arm out function it immediately lifts off ground.
do i have a wrong pipe somewhere??

boom trouble with hyundai 290

Hydraulic fitting turns too far.

Sorry I don't have any pictures at the moment so this may be confusing.
At some time in the past the 90 degree fitting on the boom of my backhoe was turned too far. This fitting eventually leads to the ram that controls my bucket. On one side of the machine the fitting points downward and the hose runs under the pivot point. On the other side the fitting points back and up and the hose runs over the the arm pivot, causing the hose to rub on the pin. Of course this led to wearing a hole in the hose, also the hose was bent into an awkward 'S' shape instead of a nice gentle single arc like the other side so I think that it is not correct. I have replaced the hose and I want to turn the fitting to match the side that didn't look like an 'S' or have a hole. The 90 degree fitting in question isn't a two part fitting like the hose, it is a single piece that threads to a 'bottom out' with an O ring. this fitting threads into a piece that has a big nut on it and I thought that tightening this nut a lot would pinch the 90 fitting and lock it in place but it does not. the fitting remains sloppy loose unless I bottom it out which puts me back into the hose rubbing scenario. I could just tighten it down and resign myself to replacing the hose again soon but it seems to me that if the torque on the 90 is all that keeps it from turning then it is just a matter of time before it loosens itself anyway.

What am I missing here? I can't get to the fitting that the 90 threads into because it is a steel line inside the arm. the only things I can put a wrench to are the 90 and the nut and the two don't seem to have any effect on each other.

If the 90 had a good new o ring, can it be left loose? that sounds ridiculous to me, but I don't know how else I can get the hose to run the 'right' way.

Hydraulic fitting turns too far.

773g fuel solenoid problems

I have replaced fuel solenoid and still can't start it up.
When cranking the pull works, but the hold doesn't keep it in. I tested the hold wire and it read only 5.6v, which should be 12. I checked the fuses and relays. Does anyone have any ideas what is going on with this thing?

773g fuel solenoid problems

2006 Atlas Copco Roc F9-11(knuckle boom)

Hello, my name is Josh. I was just assigned to this 2006 copco F9 and am drilling through some really hard red stuff in Pennsylvania right now. She's got a 2550 top hammer with t51 steel and turning a 4 1/2" button bit. I noticed the steel had a lot of vectors vibration and wobble to it than normal(accumulators are freshly recharged and replaced). So I turned my settings up a bit all the way around to stabilize things a bit. I was hoping someone here could provide me with a definitive on whether or not this hammer can take this sort of beating without damaging anything. Keep in mind I would rather not risk the striking rod, but I'm also on a tight schedule and a striking rod is not a blown hammer so I'm ok with that. Specs listed below.

Atlas Copco Roc 2550 top hammer
High impact pressure: 210 bar
Low impact pressure: 140 bar
High feed: 70 bar
Low feed: 40 bar(any lower and the hammer dry fires)
Rotation torque: 30-50 bar
Dampening: 50-55 bar

Thanks for reading.

2006 Atlas Copco Roc F9-11(knuckle boom)

3208 governor question

So this is probably more of an engine question than a excavator one. I have a 87 229 Cat. I recently installed a 3208 that was taken out of a highway truck. Everything is good except the throttle control(revs up until I load the hydraulics and then drags down and almost dies. When we stop using the hydraulics it revs back up again.)

I assume it is some sort of setup issue in the fuel pump. Would a highway setup have a different governor setup? Can I adjust it somehow? I see what looks like a governor control on top of the injection pump. any help is greatly appreciated.

3208 governor question

Pictures Wanted! The Biggest Heavy Equipment You Ever Worked on!

I don't know if this has been done before or not but I think we should have a forum with pictures of the BIGGEST heavy equipment you ever worked on! Lets see those mining shovels, trucks etc. Pictures are appreciated though because like fishing and hunting stories the size increases with every story told!

Here in southern Ontario there's not that much huge equipment but Ill get us started with a recent project. Assembling container handlers.

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Pictures Wanted! The Biggest Heavy Equipment You Ever Worked on!

Cat 953 Doesnt move SOMETIMES

I have a 1998 Cat 953 (2ZN02121)that runs great most of the time, but sometimes on start up it will not move in either direction. I can shut it down & leave it & come back later or the next day & it may or may not move. When it moves, it runs great like it was a new machine.When it doesnt move, I dont know what to do other than leave it alone. Any ideas?

Cat 953 Doesnt move SOMETIMES