Dump valve issue with snowblower

[davemskinner]

Greetings,

I have a Grand L4330 with a front mount snowblower. I purchased the tractor used in the fall of 2019. I used it all winter and in the spring, I purchased a loader for the tractor. When they installed the loader there was no float to the loader. I called the dealer and they said to bring the tractor back. When I did, they fixed the problem by adjusting the cabling to the joystick. I then found the quick dump function for the bucket roll as a detented position on the joystick. Loved the loader and the functions. This past fall, I reinstalled the front mount blower which has a chute rotation function. When I hooked up the hydraulic lines, I could not get the chute to rotate to the right. Called the dealer and he explained that I need to push hard into the detented position for it to work. He was right. The chute function works as it should.

Here is the gotcha, the detente is hard to override and often the chute turns too far because of the force needed to override the detente. Is there some way to temporarily lock out the detente while the snowblower is on and then return it to normal when the loader is reinstalled?

 

[Dave_eng]

Greetings,

I have a Grand L4330 with a front mount snowblower. I purchased the tractor used in the fall of 2019. I used it all winter and in the spring, I purchased a loader for the tractor. When they installed the loader there was no float to the loader. I called the dealer and they said to bring the tractor back. When I did, they fixed the problem by adjusting the cabling to the joystick. I then found the quick dump function for the bucket roll as a detented position on the joystick. Loved the loader and the functions. This past fall, I reinstalled the front mount blower which has a chute rotation function. When I hooked up the hydraulic lines, I could not get the chute to rotate to the right. Called the dealer and he explained that I need to push hard into the detented position for it to work. He was right. The chute function works as it should.

Here is the gotcha, the detente is hard to override and often the chute turns too far because of the force needed to override the detente. Is there some way to temporarily lock out the detente while the snowblower is on and then return it to normal when the loader is reinstalled?

No, you have the detent all the time.

Since rotation speed really seems to be your issue, consider restricting the flow on the blower so movement is slower.

Local hydraulic shops should be able to supply you with a fitting with an orifice. Get a small orifice as you can always drill it out to be larger.

Orifice fitting

It your chute rotation is via a hydraulic motor, my inclination would be to install an orifice on each hydraulic line.

Dave

 

[davemskinner]

Dave, Thank you for the reply. Basically that really sucks. I also have a very bad shoulder and pushing thru the detente kills me with sharp stabbing pain. I have a new shoulder coming this Friday which will solve that problem (once I recover) but the detente will probably be a problem for my wife while I am recovering.

Another thought, when I bought the machine, before I had the loader installed, the chute rotation was not an issue. There was no detente. Even with the loader the bucket rolls well without the dump feature. Why can't the chute move until the detente is passed? The bucket moves and there is no different hose connection between the two attachments.

 

[Dave_eng]

Dave, Thank you for the reply. Basically that really sucks. I also have a very bad shoulder and pushing thru the detente kills me with sharp stabbing pain. I have a new shoulder coming this Friday which will solve that problem (once I recover) but the detente will probably be a problem for my wife while I am recovering.

Another thought, when I bought the machine, before I had the loader installed, the chute rotation was not an issue. There was no detente. Even with the loader the bucket rolls well without the dump feature. Why can't the chute move until the detente is passed? The bucket moves and there is no different hose connection between the two attachments.

I will try and explain the difference between the bucket and the chute.

The bucket wants to fall forward because of its weight and the mounting hinge point at the rear of the bucket. The chute rotation does not have gravity assisting its movement.

Designers of loaders are also trying to avoid what is sometimes referred to as a floppy bucket. Below is an explanation I found.


Regen is a "feature" of most modern FEL (Front End Loader) valves, it's on the Dump circuit, and is also referred to as "Fast Dump". The reason it is nice to have is that without it, the weight of a filled bucket can actually "pull" the bucket down faster than the fluid can enter the other side of the cylinder, this will create a air pocket and give the bucket a "floppy" feeling until the joystick is held in the dump mode a few seconds to refill the cylinder pushing the air past the seals. So we add "regen" or "regenerative" function to the valve.

Regen solves this problem by actually filling both sides of the cylinder at the same time with hydraulic fluid. But how will that work you might ask? Well, because there is more volume on the side of the cylinder that extends it since the rod is taking up space in the other side, it "overpowers" the rod side and lets the cylinder extend-thereby dumping the bucket. So since now both sides of the cylinder are "pressurized", the air pocket can not develop, eliminating the "floppy" bucket syndrome. One other added bonus is that the bucket actually dumps faster due to the higher flow rate required to do all this, that's why it's referred to as "fast dump" sometimes.


In your loader operation you are using gravity all the time to dump the bucket and hydraulic fluid is not coming from the pump into one end of the cylinder. When you want the same control valve to rotate the chute now you need hydraulic flow from the pump hence the need to utilize a different position of the valve.

I suggest you consider asking your dealer to completely remove the detent components for this winter. It is a collection of ball bearings and springs located in a metal cap at the end of the spool valve for the bucket. I have not done this before and do not know how the valve will operate without these parts.

If your tractor sits outside, the mechanic may find moisture has gotten into the metal cap and rusted the ball bearings making operation more difficult than it has to be.

Another thought....... The blower is raised and lowered hydraulically. Gravity will lower the blower as long as the loader valve lets it which parallels the bucket operation. Try swapping the hoses. Connect the loader arm hoses to the chute rotation and the bucket hoses to raise and lower the blower.

If you decide to try either of these suggestion, please report back as your experience will add to everyone's knowledge.

Dave

 

[davemskinner]

Dave, I just wanted to let you know that I haven't tried swapping hoses yet due to the shoulder replacement surgery. I'm 11 days out and could not be happier withe the surgery. However, I cannot use the muscles required to push in the connecters. I Ned another week or so of healing.