Green Tractor Talk banner
1 - 8 of 8 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
I have an 855 with a 70A Loader. The Bucket seems to have a lot of play; especially when the hydraulic cylinders on the bucket are extended and the bucket is facing down towards the ground like it would if I am back-blading.

So I tilt the bucket forward until the blade is straight down. If I put lower the bucket to the ground and them back up the tractor, the bucket will tilt forward almost 90 degrees before it catches. Then I have to continue to tilt down until the bucket is forced down into position. This slop is a real pain. It is like there is a lot of air in the line but I cannot clear it out.

If I tilt the bucket back up so the blade edge is pointing forward and then lower the bucket to the ground, there is very little play.

What is going on here?

Thanks to all for your help.
 

·
Registered
Joined
·
514 Posts
BKunde,

With the bucket vertical, you have about 3 feet of leverage to push back against the seals in the curl cylinders. Not sure if the seals are worn allowing oil to bypass. Try backblading by lowering the cutting edge less than 1 foot below horizontal. Less leverage on the cylinders. Most operators do it this way. I have seen some do it the way you do, but not many. Not saying you are doing it wrong. Different ways to do things

Dave
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #3 ·
Some have replied that the problem I am having it because when I tilt the bucket forward, the weight of the bucket and whatever is in it rolls the bucket faster than the hydraulic pump can fill the cylinders, so they suck air into the system. Then I have to wait until the system catches up. If this is the problem, where is the air getting in and is there anything I can do to stop it? Thanks.
 

·
Registered
Joined
·
514 Posts
It’s not that air is being introduced into the system. The bucket in the vertical position is acting against as its own hydraulic pump and is pushing against the tractor pump which can’t keep up. Short of checking and increasing the hydraulic pressure, or replacing the pump itself, there aren’t very many options, other than as I pointed out to backblade with the bucket in a more horizontal position.

One of the suggestions for people who have installed an aggressive tooth bar and want to back blade, it was recommended to use the backside of the bucket with the bucket pointed up so 5he teeth aren’t engaging the soil

Dave
 

·
Administrator
Joined
·
20,876 Posts
Air can be sucked past the seals in the cylinders, the same way it can be pushed out when a new one is installed.

That issue is corrected with what's called "regen" or the regenerative function of the valve-if you have it on that older machine.

 

·
Registered
Joined
·
3 Posts
Discussion Starter · #6 ·
Dave, yes, I understand and agree. I have a tooth bar on my bucket and I'm clearing scrub brush which works best when I drive into it and lower the bucket with the teeth down, then back drag.

I did some more playing around with this problem yesterday. If I tilt/roll the bucket forward slowly, I don't get the slop. Openly when I tilt is at full speed.

Now that I am thinking about this, the 70A loader has Flow Restrictors that have been removed to get the loader to operate faster. I bet if these restrictors were re-installed, this problem would go away or at least be less of an issue. I remember when the restrictors were installed the loader moved Sooooo Slowww.

Thanks for your help.
 

·
Registered
Joined
·
514 Posts
The loader manual shows two orifice restricters, different sizes for the loader cylinders and the bucket cylinders.

They also recommend when reverse leveling to angle the bucket between 30 and 45 degrees, max of 45 degrees as this could damage cutting edge or loader linkage

Dave
 

·
Registered
Joined
·
3,145 Posts
I have changed several lines on mine with no issue.

That said

The last line I changed ....took forever to get the air out of the system and I had this Floppy Bucket thing going on.

Tried everything.....Its now finally back to normal.

What or Why what was happening happened...IDK.

I raised & lowererd loader and cycled bucket.......pulled up a steep hill did it again...drove down a steep hill did it some more.

Finally fixed itself.

1st encounter with this in 20+ years.
 
1 - 8 of 8 Posts
Top