SuiteSuccess Posted August 11, 2015 Report Share Posted August 11, 2015 I have a Kubota B7200 with a front end loader. The hydraulic valve that operates the front bucket is "sticking" when trying to lower the bucket arm making it very jumpy going down. All other functions are normal. Any hints before I tear into the valve or have to purchase a new one? I have tried lubricant etc with no luck. Seems to be internal to the valve. 2006 Volvo 780 "Hoss" Volvo D12, 465hp, 1650 ft/lbs tq., ultrashift Bed Build by "JW Morgan's Custom Welding" 2017 DRV 39DBRS3 2013 Smart Passion Coupe "Itty Bitty" "Don't go around saying the world owes you a living. The world owes you nothing. It was here first!" Link to comment Share on other sites More sharing options...
VegasFlyer Posted August 11, 2015 Report Share Posted August 11, 2015 Could be an o-ring in the valve body that is either physically sticking or allowing a small amount of bypass. John Southern Nevada 2008 Volvo 780, D13, I-Shift 2017 Keystone Fuzion 420 Toyhauler 2017 Can-Am Maverick X3-RS Link to comment Share on other sites More sharing options...
jkoenig24 Posted August 11, 2015 Report Share Posted August 11, 2015 I've used a product called "Seafoam". It's an additive that cleans gunk and gummy deposits. I know it can be added to gasoline and diesel fuel. Check the label and see if it would be OK to add an ounce to the hydraulic fluid. If you can, the Seafoam might clean your hydraulic system. http://hildstrom.com/projects/seafoam/ Link to comment Share on other sites More sharing options...
SuiteSuccess Posted August 11, 2015 Author Report Share Posted August 11, 2015 Thanks. 2006 Volvo 780 "Hoss" Volvo D12, 465hp, 1650 ft/lbs tq., ultrashift Bed Build by "JW Morgan's Custom Welding" 2017 DRV 39DBRS3 2013 Smart Passion Coupe "Itty Bitty" "Don't go around saying the world owes you a living. The world owes you nothing. It was here first!" Link to comment Share on other sites More sharing options...
Rick Posted August 11, 2015 Report Share Posted August 11, 2015 I use Sea Foam in just about everything including my airplane. This is really great stuff. http://seafoamsales.com/trans-tune/ Rick US Army 5th SFG (Retired) "To Liberate the Oppressed" Life should not be a journey to the grave with the intention of arriving safely in an attractive and well-preserved body, but rather to skid in sideways, no money left, a cigar in one hand, a whiskey in the other, body thoroughly used up, totally worn out, and screaming "WOO-HOO, what a helluva ride!!" Link to comment Share on other sites More sharing options...
Alie&Jim's Carrilite Posted August 11, 2015 Report Share Posted August 11, 2015 SeaFoam is made to be burned off. I wouldn't put it into a hydraulic system. It does sound like an O-ring has unseated or some dirt has gotten into the valve body itself. Is there a filter on the system anywhere like our steering systems on the trucks? I'm thinking that it's a regular push/pull plunger type valve with several O-rings. Not hard to rebuild with the right kit. Alie & Jim + 8 paws 2017 DRV Memphis BART- 1998 Volvo 610 Lil'ole 6cyl Cummins Link to comment Share on other sites More sharing options...
skp51443 Posted August 11, 2015 Report Share Posted August 11, 2015 Leave the bucket a couple feet in the air when you tear into the valve, it will make a great youtube video! Seriously get everything down and solidly resting on the ground to avoid the joy of getting sprayed with oil and launching the small bits into the weeds which makes finding them for reassembly so much fun. Might be worth flushing and refilling the system if it is older, a new filter if you have one is a great idea too. First rule of computer consulting: Sell a customer a Linux computer and you'll eat for a day. Sell a customer a Windows computer and you'll eat for a lifetime. Link to comment Share on other sites More sharing options...
GeorgiaHybrid Posted August 11, 2015 Report Share Posted August 11, 2015 Try this: https://parts.cat.com/en/catcorp/1u-9891-1u-9891 It is an additive from Cat to eliminate a sticking cylinder. It has worked on everything we have put it in with "sticky" parts that have a build up on them..... If that doesn't work, you will need to tear into the valve body to see what is going on. 2017 Kenworth T6802015 DRV 38RSSA Elite Suites2016 Smart Prime Link to comment Share on other sites More sharing options...
adept99 Posted August 11, 2015 Report Share Posted August 11, 2015 Carl; Try to avoid pulling the valve spool out of the valve body if you can. Look at the centering spring and make sure it is not broken or collapsed. Change the fluid filter if there is a separate system. I don't recommend additives such as rust inhibitors or anti foaming agents for hydraulic oil. Should already be in the oil. Open the old filter and see how much crud is in it. Silt is normal, chunks aren't. If you do pull the valve spool out, make sure that you mark it in some indelible fashion so you can reinstall it EXACTLY as it was removed. Keep the sandpaper, emery cloth, whetstones, and files in the tool box. They just make a "leaking by" situation worse. Do not smooth the sharp edges of the spool lands. Exception is for a gouge in the spool with a matching gouge in the valve body. If the gouge is only part way across the land and there is a raised sharp edge on the edge of the gouge, you might get by with very carefully stoning the edge of the gouge. Remember that the spools are hand fit (even the cheap ones) unless they are the low pressure o-ring type, so anything you do that removes material from either the spool or the valve body increases the "gap" between the spool and the valve body and, consequently, increases the potential for leaking past the internal seals. Paul Paul & Paula + Daisy the amazing wiggle worm dog... 2001 Volvo 770 Autoshift, Singled, w/ Aluminum Bed - Toy Draggin 2013 395AMP XLR Thunderbolt Toy Hauler 2013 Smart Passion 2012 CanAm Spyder RT 2013 Harley Davidson Street Glide Link to comment Share on other sites More sharing options...
rickeieio Posted August 11, 2015 Report Share Posted August 11, 2015 No additives. Like Prego, it's already in there. It sounds like you have a sticking spool valve, as Paul suggests. My guess is that you have an o-ring that's got a tear in it, with a sliver getting caught in the lands. I'm not that familiar with Kubota valves, but it can't be that difficult. The fact that it's happening when you're trying to lower the unit leads me to believe it has nothing to do with a clogged filter. Like Stanley said, be sure ALL pressure is bled off before any dis-assembly. Can you post a pic of the offending valve? One other thought, you might ask the service manager at your Kubota dealer. It might be a common problem. Yet another idea: does the valve stick when the tractor is not running? Try just moving the lever without starting. If it sticks, you need to service the valve. I'm gonna go out on a limb and suggest it will involve no more than a pin and a packing nut to access the spool valve. KW T-680, POPEMOBILE Newmar X-Aire, VATICAN Lots of old motorcycles, Moto Guzzi Griso and Spyder F3 currently in the front row Young enough to play in the dirt as a retired farmer. contact me at rickeieio1@comcast.net Link to comment Share on other sites More sharing options...
SuiteSuccess Posted August 11, 2015 Author Report Share Posted August 11, 2015 Thanks to everyone. Rick will try to get a pic this afternoon. Unfortunately the Kubota people here just want to sell new parts. Every time I've been in with a question always get the " just need to replace it" talk. And Kubota parts are pricey. GeorgiaHybrid, my tractor has a common sump apparently with the hydrostatic transmission so the Cat product wouldn't work but thank you for the help. Stan: very aware about releasing all pressure on system. Changed out a leaking quick connect without all the pressure off. Lucky I was in the grass or my garage would have been a mess. 2006 Volvo 780 "Hoss" Volvo D12, 465hp, 1650 ft/lbs tq., ultrashift Bed Build by "JW Morgan's Custom Welding" 2017 DRV 39DBRS3 2013 Smart Passion Coupe "Itty Bitty" "Don't go around saying the world owes you a living. The world owes you nothing. It was here first!" Link to comment Share on other sites More sharing options...
Deezl Smoke Posted August 11, 2015 Report Share Posted August 11, 2015 Leave the bucket a couple feet in the air when you tear into the valve, it will make a great youtube video! Seriously get everything down and solidly resting on the ground to avoid the joy of getting sprayed with oil and launching the small bits into the weeds which makes finding them for reassembly so much fun. Might be worth flushing and refilling the system if it is older, a new filter if you have one is a great idea too. Ha, ha, ha !!!!!!!!!! That one caught me off guard Stanley. Definitely youtube is the place to watch that stuff. But I would change the hoses between the curl and the lift and see if the valve still sticks to make sure there is nothing down stream causing an issue. Then rest everything on the ground and look into the valve for a faulty back up ring or galling on the spool. Kubota is good at keeping things clean and is a good brand of tractor. However, a small particle of something can still get past and end up between the spool and bore, or between the o-ring and it's back up ring. I'm a work'n on it. Link to comment Share on other sites More sharing options...
rickeieio Posted August 11, 2015 Report Share Posted August 11, 2015 Good thoughts Deezl. I'm not familiar with that model and don't know if his dis-connects are before or after the controls. If they're between the loader and valves, you're likely on the right track. At any rate, this is pretty simple, we hope. KW T-680, POPEMOBILE Newmar X-Aire, VATICAN Lots of old motorcycles, Moto Guzzi Griso and Spyder F3 currently in the front row Young enough to play in the dirt as a retired farmer. contact me at rickeieio1@comcast.net Link to comment Share on other sites More sharing options...
shorts Posted August 11, 2015 Report Share Posted August 11, 2015 Look at the springs that center the valve spool they should be on the ends of the valve spool usually opposite of the handle. The O-rings and wipers to seal the valve spool should be on the ends of the spool, the internal seals are the grooves around the spool and close tolerances, no rubber parts, it's called a Labrith seal, ck spelling. If the valve operates smoothly with the handle your problem is somewhere else, either in the cylinders or lines, most likely a hose delaminating internally and acting like a flapper valve. Link to comment Share on other sites More sharing options...
rickeieio Posted August 11, 2015 Report Share Posted August 11, 2015 What Shorts said. Do you feel the "catch" in the handle, or is it in the motion of the bucket? Should have asked that long ago....... KW T-680, POPEMOBILE Newmar X-Aire, VATICAN Lots of old motorcycles, Moto Guzzi Griso and Spyder F3 currently in the front row Young enough to play in the dirt as a retired farmer. contact me at rickeieio1@comcast.net Link to comment Share on other sites More sharing options...
sclord2002 Posted August 11, 2015 Report Share Posted August 11, 2015 The Sea Foam that was mentioned earlier was the Sea Foam Trans Tune which is made for Transmissions and hydraulic systems. It is harder to find than the Sea Foam for engines. I have used the Trans Tune in hydraulic systems to eliminate "stiction" and it has worked. It is not totally magic, so it won't cure everything but it is often worth a try....just my opinion, though. Charlie Don't ever tell a soldier that he doesn't understand the cost of war. Link to comment Share on other sites More sharing options...
jkennell Posted August 11, 2015 Report Share Posted August 11, 2015 Suite: We really need to know what Rick says above. There is a major difference between a valve that "feels" stiff, so its hard to feather the motion, and the actual movement that jumps when you activate the valve. If its the loader itself that jumps, you may have a bad hydraulic coupler. See if you reverse hoses to isolate the problem. I also know of a loader that jumped because of a sticky check valve on the lower function (designed to hold the loader from sinking...it worked a bit too well!) A stiff lever on the other hand...go ahead and pull apart the valve, clean thoroughly, and replace the orings. Make sure any "indent" ball/spring assemblies are loose. A very common problem is a frozen indent ball. Do not let them talk you into a whole new valve body for this unless its leaking. See if you can't find a exploded parts diagram...ask your dealer for a print "so you can see what part you will need!" No camper at present. Way too many farm machines to maintain. Link to comment Share on other sites More sharing options...
SuiteSuccess Posted August 11, 2015 Author Report Share Posted August 11, 2015 Here are some pics of my valve. My loader is a Woods not a Kubota so sorry for the mistake. The sticking seems to be in the valve itself. As I push the stick up you can feel a catch then it will " break" and the bucket will jump. The tractor is Kubota 2006 Volvo 780 "Hoss" Volvo D12, 465hp, 1650 ft/lbs tq., ultrashift Bed Build by "JW Morgan's Custom Welding" 2017 DRV 39DBRS3 2013 Smart Passion Coupe "Itty Bitty" "Don't go around saying the world owes you a living. The world owes you nothing. It was here first!" Link to comment Share on other sites More sharing options...
SuiteSuccess Posted August 11, 2015 Author Report Share Posted August 11, 2015 More pics 2006 Volvo 780 "Hoss" Volvo D12, 465hp, 1650 ft/lbs tq., ultrashift Bed Build by "JW Morgan's Custom Welding" 2017 DRV 39DBRS3 2013 Smart Passion Coupe "Itty Bitty" "Don't go around saying the world owes you a living. The world owes you nothing. It was here first!" Link to comment Share on other sites More sharing options...
SuiteSuccess Posted August 11, 2015 Author Report Share Posted August 11, 2015 Couple more 2006 Volvo 780 "Hoss" Volvo D12, 465hp, 1650 ft/lbs tq., ultrashift Bed Build by "JW Morgan's Custom Welding" 2017 DRV 39DBRS3 2013 Smart Passion Coupe "Itty Bitty" "Don't go around saying the world owes you a living. The world owes you nothing. It was here first!" Link to comment Share on other sites More sharing options...
rickeieio Posted August 11, 2015 Report Share Posted August 11, 2015 Here are some pics of my valve. My loader is a Woods not a Kubota so sorry for the mistake. The sticking seems to be in the valve itself. As I push the stick up you can feel a catch then it will " break" and the bucket will jump. The tractor is Kubota Make of the loader doesn't matter now. You've isolated the problem to one spool valve. These things are crazy simple. Take your time and pull it apart, being careful that nothing falls into the grass. A catch pan is good, a towel is better (parts won't bounce). I'm betting on an o-ring with a bad spot hanging in the bore. I'll go out further on that limb and predict you only need one o-ring, but if they offer a seal kit for each valve, get it. Can't be more than a few parts in the entire kit. Look up your model # loader and see if they have an online parts catalog. Kits are normally at the bottom of the page. KW T-680, POPEMOBILE Newmar X-Aire, VATICAN Lots of old motorcycles, Moto Guzzi Griso and Spyder F3 currently in the front row Young enough to play in the dirt as a retired farmer. contact me at rickeieio1@comcast.net Link to comment Share on other sites More sharing options...
SuiteSuccess Posted August 11, 2015 Author Report Share Posted August 11, 2015 Thanks so much Rick. Do I need to drain all my hydraulic fluid before removing the valve? If so where is best to bleed the air from the system? 2006 Volvo 780 "Hoss" Volvo D12, 465hp, 1650 ft/lbs tq., ultrashift Bed Build by "JW Morgan's Custom Welding" 2017 DRV 39DBRS3 2013 Smart Passion Coupe "Itty Bitty" "Don't go around saying the world owes you a living. The world owes you nothing. It was here first!" Link to comment Share on other sites More sharing options...
rickeieio Posted August 11, 2015 Report Share Posted August 11, 2015 It's too bad we aren't about 200 miles closer. You have some interesting projects. I just have maintenance. For instance, I drained about 9 gallons of 3 y/o gas out of the generator tank today. Doesn't smell that bad. I'll run it through my only gas tractor. At 66 years old, it won't care. Now I need to get 5 gallons of av gas to put in the genny tank and run it for a bit. KW T-680, POPEMOBILE Newmar X-Aire, VATICAN Lots of old motorcycles, Moto Guzzi Griso and Spyder F3 currently in the front row Young enough to play in the dirt as a retired farmer. contact me at rickeieio1@comcast.net Link to comment Share on other sites More sharing options...
orca Posted August 11, 2015 Report Share Posted August 11, 2015 It's too bad we aren't about 200 miles closer. You have some interesting projects. I just have maintenance. For instance, I drained about 9 gallons of 3 y/o gas out of the generator tank today. Doesn't smell that bad. I'll run it through my only gas tractor. At 66 years old, it won't care. Now I need to get 5 gallons of av gas to put in the genny tank and run it for a bit. Just curious, but what is the advantage (other than higher octane) to using av gas? 2004 Freightliner m2 106 2015 DRV lx450 Fullhouse 2019 Indian Springfield 2014 Yamaha 950 V-Star Link to comment Share on other sites More sharing options...
shorts Posted August 12, 2015 Report Share Posted August 12, 2015 Avgas will be alcohol free and probably still has a lead additive to help lubricate and cool the valves Link to comment Share on other sites More sharing options...
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