L48 backhoe Hydraulics

[PL&L]

Hi everyone this is my first post here so please be kind

This week I purchased a L48 TLB. I LOVE the machine but the controls on the back hoe are backwards for me. Long story short I swapped one function to the other handle.The controls are the way I want them now, but I think that they need to be adjusted.
Now, the Boom is bleeding down at a visible rate and the Dipper is ok once extended but makes alot of noise getting there if the valve is opened more than 1/4 of the way. I thought this might be due to air but I think that it has to do with relief or detent valves. I ran the machine for a good 1/2 hour after I made the change. I was not working it under load just in the air. The problems didnt go away.

Is it Ok that I did this? The valves and lines are the same size but I guess detents or reliefs may be different. I know that it probably would have been easier to learn the new pattern but all of the fine movements were on the left stick and I am right handed. It would be like learning to write left handed. I just dont have time for that.

I am going to call the dealer tomorrow but I am looking for some advise before I do that. Should I expect that they are going to tell me that I cant switch them or that the cost to adjust the valves is going to be absurd.

Thank you for your help and advise
Bill

 

[RonMar]

Well if you swapped the fittings back and it works normally, that would prove that there is a hidden circuit in there. Did you by chance swap the boom left-right control to another circuit? If so, that could be one of the problems. Some backhoes add a separate relief valve to that circuit which is also usually comprised of smaller cylinders. This limits the availabe side force to help prevent mount damage and possibly tipping the tractor over. Putting that circuit on another control, the weight of the structure may be overcomming that safety which would explain the leakdown.


I would say return it to original and try it. If it again works properly, it is probably best to learn the factory control scheme. I would guess that this is probably what the dealer will tell you.

Good luck

 

[PL&L]

Thanks Ron,

I did put it back and its Ok again. I didnt switch the boom swing I swapped the boom up/down with the dipper in and out. I am guessing that there is an internal setting on the valve which can be adjusted. The Boom on this thing looks like it weighs ALOT so that would explain the bleed down. I will see what the dealer says though. I would rather pay a few bucks and be able to be more productive.

Thanks Again

Bill

 

[Dirthog]

You will find the spool in the valve is different and also the valve could be ported different inside they are made that way because different functions need oil flow/pressure at different rates

 

[LarryRB]

I've had a 48 for three years now,, Been an awesome machine, Although I did thousands of hours with a deere 710 hoe and am use to ISO pattern, You obviously are use to SAE or some call it caterpillar/case pattern., My dipper bleeds down also. We don't have the lock out valves like the bigger machines do and thus the bleed down. I'm so use to using the pin in the dipper that it is second nature and not a bother, Pull pin, use hoe, finish, replace pin. After a few digging jobs, you won't even realize your doing it,

 

[dfkrug]

You will find the spool in the valve is different and also the valve could be ported different inside they are made that way because different functions need oil flow/pressure at different rates

I think that is the key.

Different valves in the stack may use flow restrictors if the spool itself is
not different. Also note that not every valve may use 2 "shock relief"
valves in each work port or the shock relief setting (not adjustable) may
be different.

Good thing PL&L did not swap swing cyl controls as the L48 has a
separate pump for swing.

 

[PL&L]

Thanks Alot guys.

I think I am going to stick it out for awhile. If I get so I cant stand it I will pull the valve body apart and switch them that way.

By the way, I am going to rent a Hydro auger that is bobcat. Will I have an issue with hydro fluid? I am going to try to bleed as much out of the unit as possible before I connect it?

Thank you again

Bill Boroskey

 

[LarryRB]

Pl & L
don't know where you live, however, I run super UDT in my 48 and refuse to allow other fluid to mix with it.,..

 

[dfkrug]

Thanks Alot guys.

I think I am going to stick it out for awhile. If I get so I cant stand it I will pull the valve body apart and switch them that way.

By the way, I am going to rent a Hydro auger that is bobcat. Will I have an issue with hydro fluid? I am going to try to bleed as much out of the unit as possible before I connect it?

Thank you again

Bill Boroskey

Yeah, that's the right way to switch controls.

As for the hydraulic PHD, the good news is, unlike hyd cyls, the hyd motor
in the PHD will not have lots of fluid in it. But DO drain the hoses to
minimize the mixing with your UDT or SUDT fluid in your tractor. You could
even connect up only one hose and put the other in a bucket. Then
run the unit for a few seconds and flush out the old fluid. You will have to
remove the QD fitting, if there is one.

In my hyd PHD, the hoses have more fluid in them than the hyd motor.