[robpm]

I wasn't sure whether to post this under attachments or under Hydraulics so that is why I put it here since it has to do with the tractor more than anything and specifically to the hydraulic outputs on the tractor. So feel free to move it around if you prefer it some other place if you moderators deem it necessary.

I have a question regarding my 990 and the 8B BH and specifically when running the BH. In the 990 specifications it states that the "Rated Engine Speed" is "2700 RPM". Now when you look under the hydraulic specs it states "Pump Capacity (Main) at Rated Speed" and gives "8.5 gpm". Does that mean that in order to get the 8.5 gpm you would need to run it at the rated capacity which is 2700 RPM. If I ran it at 1500 RPM would the gpm go down or would it stay at 8.5 gpm? I am guessing that it does drop since it is a Open Center Dual Gear pump on the tractor. If it does decrease will the power of the BH decrease as well with the drop of flow or will just the speed of the movements.?

What about the pressure as well. Does that stay the same or decrease? It is suppose to be at 2262 PSI and does not state anywhere about the fact that this is at Rated Speed so I am guessing that the pressure truly stays at 2262 never mind what the rated speed is or for that matter who is in the White House!.

Thanks

Rob

 

[Kennyd]

Rob, pressure is constant, flow is variable. The "rated" GPM's are usually at PTO RPM. PSI does the work, GPM determine's how fast it gets done.

 

[robpm]

Thanks Kenny that is what I thought.

I have read on other forums of people upping the pressure by putting spacers in. Is that a good thing to do or not?

Rob

 

[Kennyd]

I don't recommend increasing the pressure. I suggest learning to work within the machines capabilities, if you need to increase pressure to get a job done-then you have the wrong machine.

I do however suggest having a gauge setup to test the PRV (pressure relief valve) because they can get weak over time. You can assemble one for about $40.00 or drive to my house and borrow mine:laugh:

 

[robpm]

I don't recommend increasing the pressure. I suggest learning to work within the machines capabilities, if you need to increase pressure to get a job done-then you have the wrong machine.

I do however suggest having a gauge setup to test the PRV (pressure relief valve) because they can get weak over time. You can assemble one for about $40.00 or drive to my house and borrow mine:laugh:

OK that sounds good. Where can I buy the parts to assemble one and where should I connect it into the system to test the PRV? Cause I ain't drivin to your house, at least not tomorrow and especially not on the 990!

Rob

 

[Kennyd]

Give me a day or two and I will post a thread on it...

 

[robpm]

Sounds good. I will look forward to it.

Rob

 

[RandyM]

Yeah, me too!

 

[Kennyd]

Sounds good. I will look forward to it.

Rob

Yeah, me too!

Done. Bill is in the mail :mocking:


http://www.greentractortalk.com/for...ic-Pressure-on-your-Tractor&p=28587#post28587

 

[robpm]

Done. Bill is in the mail :mocking:


http://www.greentractortalk.com/for...ic-Pressure-on-your-Tractor&p=28587#post28587

Kenny thanks very much. I would guess I could hook this gauge setup to my front loader by disconnecting the curl cylinders and connecting this up and use the joystick for the curl to test it since I do not have a rear SCV. One could not use the PB circuit because that needs to be open.

It looks like you have pretty good pressure there on your 4110 :thumbup1gif:.

Rob

P.S. The check is in the mail :laugh:l

 

[Kennyd]

Any port will do Rob...like I wrote-I only used the rear since the blade was plugged into the front.