Hi all , finally getting the dead ec460 I bought back together. Cranked it Saturday and blew a few Hyd hoses that weren’t noticeably bad, I briefly lived the boom off the ground and set it back down before shutting the machine down. Monday I replaced the hoses and had no hydraulic function whatsoever. Replaced a relay above the battery box I was told managed the lock out function and still had the same problem. Tech told me to push the nipple down on the solenoid underneath the pump nearest the counter weight and if I had functions the solenoid was bad. Did just that and everything worked properly, he recommended I switch the next solenoid over to the safety solenoid position which I did, everything works but can’t boom down, does the second solenoid/valve control boom function? Serial number EC460V10676
Good day You may find the attached helpful. Kind regards Uffex
Boom down is spool controlled. There are 2 , boom 1 & 2. No solenoids involved aside from safety solenoid. I would gauge pilot oil to both sides of boom 1 spool. Let's see if the signal is getting to the MCV. If the oil is reaching the valve, you're going to want to carefully support the boom from free fall and crack the lines loose to the barrel side of either cylinder. If the boom still refuses to lower, the packing nut and washer have probably come off the rod. When this happens, the safety washer acts like a check valve. It lets oil into the cylinder then blocks the oil passage when retracting. Good luck. You have a B series in America, it's unlikely, but worth mentioning. If you have large rectangular blocks bolted to the base of the cylinders with pilot lines and work hoses going to them, those would be boom rupture protection valves. Not common on American B series but could have been optioned. Please advise
Where do I check boom 1&2 spool at ? May be worth mentioning when I’m in the cab pushing the stick down I can hear what seems to be fluid or air coming from it.
Please see attached PDF explaining ports and positions. Let's focus on 4Pb2 and 4Pa2. That should be spool caps for boom1. That would be the center spool of the one bank. Please be careful
I replaced that one bad coil by the pump just because I didn’t want a bad one back there. I don’t have gauges available to me to check pilot pressure on the valve block. I did however crack the bottom boom cylinder lines and the boom went straight back down.
Welp, turns out it doesn’t boom down very well when the hose on the bottom of the mcv isn’t connected….
No way! the Boom down hose wasn't connected, plugged and capped?
Guessing the people I bought it from had it off to assist with moving it ? Motor was pulled due to throwing a rod. Connected it and everything works properly now. She even got a bath. The temp gauge in the cab stays on Hot as soon as you turn on the key and it won’t move down. Bad sensor or bad gauge ?
What's going on with your tracks? They are way too loose.
Looks good.
Loose from moving it when the motor was out, pumping them up tomorrow.
With track hanging should be a 11.5 to 12.25 inch sag from bottom of track frame to hanging pad.
Would #5 being disconnected result in the engine bogging while trying to dig, had my brother change a Hyd hose near it and he broke the plastic piece off. Thanks
Found the intake hose coming from intercooler to turbo had a hole in it, fixed my power problem, still would like to know what that switch/sensor does tho
Can you attach a pic of what broke.
Is it the coil that broke or the magnet retainer nut.
It is #5 on the diagram listed as a switch. Comes out of a T Two wires go to it Separate question with the arm extended out my bucket curl out function is very slow almost nonexistent at max reach, but when you retract inward towards the cab it works fine, dealer service tech says my seals may be bypassing in the cylinder, when I brought the machine home dead they had three or four round valves on the top of the control valves that were loose I assume to help with moving it around ? One of them I tightened the nut on top before I realized I needed to grab bottom piece to tighten is down. Could that be part of the issue? Everything else functions correctly.
Found this one on the underside of the mcv dripping fluid. Tightened her up and the bucket works fine now. Go figure….the one next to it closest in the picture was dripping from the set screw, I tightened it just enough to stop it from leaking. I’m assuming it adjusts pressure to something. Any advice ?
That's your port relief, i believe. You're going to want to set that to the proper values. Too weak, not enough break out force. Too tight and you're blowing hoses or piston packings
Requires gushes I assume? Do you have a procedure for this ?
Considering everything you've encountered, i would adjust everything. It's a bit of a pain in the @ss, but it's worth it when you get her working. Plus it will give you notice if one of your functions are weak or if something needs attention. Better to find out now, than when you're depending on it. Either myself or one of the other fellas with info will post up those specs. It's definitely a cardio exercise. Details to follow Monday. Most importantly, yes, you'll need a quality set of gauges. 2 with up to 6000 psi capability. Most common are 10k, easier to find. On the side of your pump are 2 nubs poking out, about the size of your finger tip. Unscrew the knurled caps and post a pic of the threaded nipple. There were 2 kinds on the B series, just want to help you get the right stuff.
.
I paid the local Volvo dealer to recheck pump pressure and anything else that could have been messed with on the MCV. He said pump was only putting out 2300~ psi. He turned it up to 4800~. Checked all the other stuff out. The boom function is sticking and has gotten worse. My guess is one of the blown pieces of trash from the boom cylinders is the cause ? They want to haul it to their shop to pull the spool and repair it. We had a old komatsu that did the same thing and we sanded the spool with fine sand paper and it works fine now… would that be the same one you mentioned on this Volvo? 4pb2 and 4pa2?
Don't forget spool @5pc3. Sorry, I'm having problems on my end with HEF. But yeah , you want to focus on Boom1 and Boom2 spools. I would not remove any material from the spool unless it's physically binding in the body. Make 100% sure there's no outside factors. Be careful
We tried honing valve body on John Deere 792E back in the day. Didn't work out. We were to aggressive. Ended up replacing with used one.
It recently started booming up on its own, got progressively worse, will boom up while your tracking and digging. It started hanging up and you could just tap the boom down and it would go back to normal. Now when it does it you must have a bucket of dirt and stick Al the way out and hit the boom down to get it unstuck.
I don't know if I asked this, do you have a pattern change valve , it's usually behind the cab. If so, make absolutely sure that valve is either in ISO or farmer. If that valve is not 100% all the way one side or the other it will cause all kinds of shenanigans with arm and boom .
. Took it out. Had to use some persuasion from the bottom of the machine to get it to go. Had a decent sized chunk of metal in one of the slots and some tiny particles. The body is kinda rough.
Well, I admire your commitment. All you can do is flush everything the best you can. Try not to remove any material from the spool itself. Only piene spots and raised edges. Don't touch the flats. You can then polish the raised edges inside the body. Again stay away from the flats. You still want the spool to seal. I hate to bring this up but you're probably gonna want to rebuild the turning joint leading to your travel motors. That and flush the motors. That's big money if they get hurt. Of course, drain and manually clean every square inch of the tank and sump strainer to protect your pumps.
I'm going to suggest pulling your arm cylinder off and checking inside. There's a snubber valve in the arm which has been known to fall apart. You'll know it when you see it. I realize this is a big job, but you're going to want to know what came apart in the first place so it doesn't continue to cause problems
I flushed the tank and replaced the suction filter and return filter after rebuilding both boom cylinders last week. This problem didn’t start untill they blew out. I’m pretty sure the debris came from them considering the left barrel was scored and the seals were out of position and riding vertically lol. They were a mess.
That's terrible. Did you see the washer between the 2 spanner nuts? I've had those trap oil in the cylinder where it won't come down. Acted like a check valve. Were you able to hone out the high spots or did you replace the can?
. Yeah the washer was fine. Honed it till it was smooth. Spool is going to be polished tomorrow. Has some burrs on its edges. I was recommended to use lapping compound with the spool to work the edges down in the valve body so I remove just enough material to get it to slide easily. Thoughts?
I would not use lapping compound. That removes material from the lands which you don't want. You only wanna knock down the high spots that bind, anything else is just too much. Same with the spool, only things that grab, don't touch the polished surfaces if you can avoid it. Good luck.
. went with a dowel and 600grit on a drill. Then used the spool itself with a ratchet. Seems to have done the job. About to reassemble.