Greetings - just picked up a 490D excavator with a strange bucket cylinder problem. Bucket travels slow, and s-l-o-w-w-e-r yet on the 'out' function, than the curl...and yet seems to improve slightly as fluid warms?!! I am hoping that the fluid is by-passing within the cylinder itself, and am attempting to remove the whole cylinder to have it gone-through. However, I cannot 'see' how to remove the bucket pins. The dog-bone pins have a collar on each side, with a bolt through them...this makes sense, yet the bucket pins seem to have nothing holding them in??? (All the pins/bushings are fairly tight for 1990 machine with 9900+ hours.) Thanks anyone for your thoughts/ideas/image/link! ~ Mark
Did you try the catalog at jdparts.com? I'd post the link but it always removes the details so you have to go through the search on your own anyway. Why do you have to take the bucket pins out to get the cylinder off? Or why do you want to take the whole cylinder off? that gland will pop off with the rod and piston pretty easily. You could also test for internal leaks in any number of ways without tools.
Hello Sir - I shall look at the web link you suggest, if it may provide an exploded diagram to help me see what's going on with whatever holds the pins in... As the cylinder is slower on the open/out function, I am hoping it is leaking internally (and not that I bought someone else's problem). Because the cylinder is leaking externally from the end, I thought start there with something that needs to be fixed as well/anyway - and take the whole cylinder to the repair shop to go through... Make sense? Thanks, Mark
With an unknown machine, I'd test it first and prioritize what gets fixed, but I'm cheap and cautious that way. Taking the cylinder in will probably be $300 minimum, the seal kits to do it yourself about $100 and not much more work than taking it off, but your call what you're comfortable with. Depends on whether you have tools to take the piston nut off, probably over 1,000 ftlbs.
Thanks again Delmer! - Yes, I'm estimating $450, but as it (the bucket cylinder) is dripping even when it sits, it's probably something that I can't delay anyway - but as you suggest, a hefty 'ding' after spending $22k on the machine, and $950 to get it home... (Plus, the starter's going too - hope I didn't buy a 28,000 # lemon!)
A lot of times these 490's have trouble with the key switch... most people just think it's the starter/solenoid.
Thanks Ronsii - yes, the key does seem like it's sketchy in terms of 'sending a signal' to the solenoid(s), and severely bent too. Plus the gages seem very interment - can a guy swap out that starter switch to some type of universal? I think a person is supposed to turn the key left(?) first, as part of the starting protocol to test the idiot lights? Key versus starter: However, a few times when I would hear a 'clack' with not starter engaged, I would climb up on the hood and tape vigorously on the starter case (a Densi versus a Delco?) and then she'd go... So in addition to a switch/key I am thinking it may be brushes or an open armature. Thanks anyone for your thoughts... ~ Mark
Brushes could be sticking or just worn down to nothing but I think the design is pretty open so probably not sticking... however for the solenoid to cause a click/clunk and not turn the starter(sometimes) the contactor or backside of the two main studs is more than likely corroded/burned... this is and easy fix if you can get the solenoid off without breaking the plastic cap the main wires go into, we have a 120 I need to rip apart again but one of the studs is seized and I don't have a spare solenoid in case I break it so the boss said leave it in a pinch you can always jump around the contacts with some one holding the key.
You know,...you're right - as long as I am to lying across the hood with my head down there, I might as well take the solenoid off first in case it is, as you say, just a fried stud... As I recall, a guy can turn the copper studs one rotation, for a new contacting surface. Why pull the whole thing out first (unless I cannot get the solenoid off/apart)! You're a genius! Thanks, Mark
Yep, the contacts is the first place I'd look, but you can test it if you want before you take the solenoid/starter off (if it happens predictably enough that you can hook up some test leads and have it happen). Denso's are good starters from what I've seen, I couldn't find replacement contacts or solenoid though. Use a file on the bent part in the middle and flip or file the studs and it should be almost as good as new. If you use sandpaper, make sure none of the grit goes back in when you put it together.
Test it first (if it happens predictably enough)... meaning place a volt meter where I can see it from the cab, and see when it 'clanks', that voltage is, or is not being transferred to the starter motor itself, FROM the solenoid - yes?
I told the boss I could remove the counterweight to make it easier to get at the starter.... he looked at me kinda funny and said "you got long arms" usually I'll rip the solenoids apart and either flip the washer or file it same with the studs, also sometimes you can find a rebuild kit for the solenoids containing all the wear bits.
EXACTLY You can run one test lead as described from the starter side of the solenoid, and another from the small "start" wire going to the solenoid, unless you're sure that it's the solenoid clicking and not a relay. Then you can test both with a ground in the cab.
Thank you both, Delmer and Ronsii! (Now if it warm above zero in the mornings... a soul crushing winter here in East Central MN.)