460 loader - pause in bucket hydraulics - help

[gvw]

When using my loader (bucket) I way to often get a 3 second pause in the reaction of the bucket to the hand lever - if that makes sense -- there also appears to be (on occasion) a lot of slop in the bucket hydraulics -- it seems to be getting worse -- any ideas??

 

[timb]

Only the bucket, not the boom (or the 3-point)?

If only the bucket, try switching the line pairs so the other DSCV channel (normally the boom) is controlling the bucket. Does the problem stay with the bucket or follow the DSCV channel? (In other words - now the boom has the delay and the bucket is fine.)

Might just need to bleed out some trapped air. How's the motion once it does begin moving - smooth or a bit jerky?

 

[RobS]

If it's only the bucket curl/dump it might be the regen feature. It's to allow faster dumping with a full bucket but can act weird when empty. Do a search on regen and you'll find all sorts of ways to explain it a lot better than I could /forums/images/graemlins/smile.gif

 

[gvw]

How does one bleed out the trapped air ??

 

[timb]

From the tech manual:

Hydraulic System Bleed Procedure -- Reason: To remove air trapped in the hydraulic system which will prevent proper operation. (Special or Essential Tools: • BW13586 Ballast Box)

Procedure: NOTE: Fill the new hydraulic oil filter with new oil before installing.

1. Install a new hydraulic oil filter.
2. Fill the transaxle with specified JDM J20D (preferred) or J20C oil to the proper level on dipstick.
3. Disconnect plug (A) to fuel shutoff solenoid. M91946
4. Turn the key to START and hold for 10 seconds. Turn the key to OFF.
5. Reconnect wires to fuel shutoff solenoid.
6. Raise machine front end and support on suitable stands.
7. Start the engine and run at low idle.
8. Slowly turn the steering wheel left and right until wheels turn smoothly indicating that any trapped air has been bled back to the reservoir.
9. Operate rockshaft several times until it operates smoothly.
10.Stop the engine and check the hydraulic reservoir oil level. Fill as needed. Check all line connections for leaks; tighten if necessary.
11.Lower the machine to the ground.
12.(eHydro machines) Drive machine in forward and reverse several times until transmission operates smoothly.

Here's a link to another thread where someone thought they had trapped air problems... Front End Loader Question

 

[gvw]

Yikes! ---part of the problem is that it is intermitent -- one day it is ok the next if falters -- arguh!

 

[KennedyDiesel]

I would assume it is worse after you dump a heavy load?

This is normal and has to do with a cavitation when the load dumps faster than the cylinder can fill to follow it.

 

[JackIL]

It sounds like a cavitation problem. Be sure to keep your engine at wide open throttle to keep the hydraulic pump working at full capacity. When you dump a bucket, do it fast instead of trying to "feather" the control lever to get a slow pour. The hydraulic pumps on CUTs are sized on the small side to keep the costs as low as possible so you have to account for this by the tricks mentioned above.

JackIL

 

[megotatractor]

<font color="green">Dude! I have the same intermittent problem with my 210 loader! Mine often crops up after using float. I get the same 3 second hesitation you describe. </font>

 

[gvw]

Thanks for the thoughts but it has nothing to do with weight of the load or speed of manipulation on the control --- the bucket simply goes limp on occasion -- not always the same and not even sure I can relate what happens prior to this phenomena -- I will simply be working away and then it happens --- move the bucket control and a several second delay before movement or I will start to drag backwards for leveling purposes and bang - limp bucket.

 

[JackIL]

OK, but are you running your engine RPM at wide open throttle? It can make a huge difference.

Please let us know specifically on this?

JackIL

 

[dltimmons]

"the bucket simply goes limp on occasion"

This happens on my 4310 w/ 420 loader all the time. I go to dump the bucket, or curl it all the way down, and it just stops for 2 or 3 seconds, then starts up again. Doesn't matter what engine speed I'm using. Doesn't matter if the bucket is empty or full.

I thought about dropping a couple of Viagra into the hydraulic reservoir to see if it will keep my bucket from going limp, but I figure if it does work, it would only be temporary anyway.

Would be nice to figure out a permanent fix, as this is really annoying, and could someday prove dangerous. Hope someone has an answer for this one.

DT

 

[trlong]

Tim,

Great! Thanks for the information. I have about 340 hr.'s now on the 4115 HST with 410 loader. Only this last week did I start to notice the hesitation from 1/2 dump to full dump of the bucket. I'll have to check to see if it follows the hydraulic lines by swiching, check "Regen", and maybe have to bleed the lines. Some times these things come on so slowly that you hardly notice until they get really slow.

Tom