hydraulic pump

[troy fox]

may be trying to fix something that is not broken ,put a kit in my hydraulic pump on a y385
and i do not know how tight the pump should be with a new kit in it ,dont want to put it on and smoke it You can turn the pump by hand (shaft side in vice) but feels a bit stiff ?

 

[oldnslo]

Do you have pictures of the pump and maybe little better explanation of what you rebuilt or replaced in the pump with the kit? Reason for asking is some if not most gear pumps have torque specs for the bolts holding the pump together. Idea on size and style of pump might help determine this.

 

[troy fox]

cant get any pics right it is at the farm now although it is a factory rotary gear pump the kit was from circle g that consisted of 2(m) seals 2 orings and a shaft seal as far as torque values it starts tighting up from finger tight to snugged down .circle g tractor sells the entire pump but this one looks new on the inside ,didn't try it before disassembly was just leaking and sucking air into hydraulics .the pump is a small pump on a y385 (25hp)engine.

 

[troy fox]

the pump is a CBN-314L at circle g tractor is a picture of it .thanks

 

[oldnslo]

It is normal for some friction on gear pumps when tightening the bolts. To tight can cause premature wear or seize them and to loose they will be inefficient from extra internal leakage.

Looking a pics do two of the bolts hold pump together while other two bolt it to the tractor? If yes I believe they all need to be torqued to the same spec. Any tightening spec listed for mtg the pump?

What diameter are the bolts? 6mm (1/4”) or 8 mm (5/16”). I might have some literature for gear pump assembly torque that could be used as reference point.

 

[troy fox]

as far as torque specs from the manual they are not any,the bolts are 8mm but i didn't try it torquing all four bolts down to see if it made any diff. with hex nuts instead of being bolted to the tractor i see how just 2 bolts would not pull it down even .

 

[oldnslo]

Troy
This torque spec is from some Rexroth literature that I have.

It shows 28 - 30 Nm for M8 bolts

I would suggest torque them in steps like 20 Nm then check how it turns, 25 check again.

Hope this helps

 

[troy fox]

thanks ,i will give it a try i have not got back to it this morning but i was thinking earlier. the bolts are bigger than 8mm i think 10mm but the same applies. Just the end torque setting The reason i was thinking 8mm was i was using a 13mm socket on that bolt and the rest for a 13mm socket were 8mm