Belt Tension system on Vermeer 505 I

[dav-lyn farm]

If you know anything about Vermeer round balers, you are probably aware of the clever hydraulic system that they use to maintain belt tension as bales are forming in the machine. I am helping a friend repair this system on his baler. I have found (I think) the problem that is allowing the system to lose pressure very rapidly. There is a faulty check valve on one of the tension cylinders. I am going to replace both check valves, but I have some questions.

How much oil is this system supposed to contain? Is it supposed to be completely full? I am concerned that it would lock up if completely full.

How do you fill and measure the amount of oil put into the system? There are no fill ports in the system, and there does not seem to be a way to see how much oil is in it.

Is it necessary to bleed air from the system and how is that done?

Any help you could provide would be greatly appreciated.

Thanks,
Dave

 

[HayDR]

If you know anything about Vermeer round balers, you are probably aware of the clever hydraulic system that they use to maintain belt tension as bales are forming in the machine. I am helping a friend repair this system on his baler. I have found (I think) the problem that is allowing the system to lose pressure very rapidly. There is a faulty check valve on one of the tension cylinders. I am going to replace both check valves, but I have some questions.

How much oil is this system supposed to contain? Is it supposed to be completely full? I am concerned that it would lock up if completely full.

How do you fill and measure the amount of oil put into the system? There are no fill ports in the system, and there does not seem to be a way to see how much oil is in it.

Is it necessary to bleed air from the system and how is that done?

Any help you could provide would be greatly appreciated.

Thanks,
Dave

It is rare that the check valve goes bad. The system needs to be recharged and have the air bleed-ed out of the system. There are 2 different valves on the I balers. One system is called Hydraulic assist and the other is called high density. The High Density system has a higher relief setting.

The Hay DR

 

[dav-lyn farm]

CCI,
Your comments are always welcome.You obviously have a significant amount of knowledge about Vermeer products.

I would need to have another look at the manual to be sure, but think this baler has the High Density hydraulic system. I do recall that the book says to adjust the system to supply 1000psi.

As it trurns out, one of the check valves was bad. I think it was a simple matter of some foreign material stuck on the seat of the valve, but I replaced both of them anyway. There was a significant improvement in the ability of the system to hold pressure. It still bleeds pressure off once it's built up, but the bleed off is reasonably slow instead of very rapid like it was before replacing the check valves. My theory is that any bleed off is not desirable and will negatively affect performance, so I'm still on the hunt to improve it.

Your comments about bleeding the system seem very appropriate, but I'm at a near total loss about how to do that. There are no fill ports or bleed valves on the system anywhere. And since there is no reservoir or "tank", cycling the system to purge the air won't work. Do you have any suggestions for performing this task?

Thanks,
Dave