Adjusting a hydraulic relief valve ?

   / Adjusting a hydraulic relief valve ? #1  

Tig

Elite Member
Joined
Oct 18, 2006
Messages
2,557
Location
The County, Ontario, Canada
Tractor
Kubota, B7100HST-D
I just added rear remotes and TnT to my B7100 and I need to set the bypass on the spool valve. The tractor hydraulics are 1700 psi. The spool valve bypass is adjustable and factory set to 2100 psi. What should the bypass be set to? 1700psi?
Where should I put the guage to measure? Can I put the guage on one of the TnT QDs creating a deadhead for test purposes? What is the correct procedure?
 
   / Adjusting a hydraulic relief valve ? #2  
You should set the valve's relief for just below the tractor safe operating pressure-in your case 1700 psi.
The gauge should be plugged into one of the QD's and the valve operated so the gauge deadhead's the pump.

Are you sure the relief is for the work ports and NOT the main in/out of the valve?
 
   / Adjusting a hydraulic relief valve ?
  • Thread Starter
#3  
Thanks for the reply, Kennyd
Looks to me that it's for the main in/out of the valve. Here is a link to the schematic. Blb hydraulic - Products - Catalog - BM Series
In that case should I be putting the gauge on the spare input port to measure the bypass pressure?
 
   / Adjusting a hydraulic relief valve ? #4  
Ditto.. set it for 1650 or something close.. and ues.. gauge into a qd is a good way.

Soundguy
 
   / Adjusting a hydraulic relief valve ? #5  
Steve:

I am missing something. If the pump has a 1700 psi relief valve, won't it always open at 1700 psi to protect the system even if there is no relief valve on your control valve? There is nothing wrong with setting the additional relief valve at 1700 psi, and I would do it if it were mine, but won't it just serve as a backup to the main relief valve?
 
   / Adjusting a hydraulic relief valve ? #6  
Farmerford said:
Steve:

I am missing something. If the pump has a 1700 psi relief valve, won't it always open at 1700 psi to protect the system even if there is no relief valve on your control valve? There is nothing wrong with setting the additional relief valve at 1700 psi, and I would do it if it were mine, but won't it just serve as a backup to the main relief valve?
I dont think youre missing anything. Yes to the rest. Actually, I dont know how youre going to set the new relief in a system limited at 1700. I guess just lower the setting til the max pressure starts to drop - then back upward slowly to find the crossover point.
larry
 
   / Adjusting a hydraulic relief valve ?
  • Thread Starter
#7  
Farmerford said:
Steve:

I am missing something.
Probably me missing something :eek:
I didn't know the pump would have a relief valve. I'm new to hydrailics and my knowledge is limited to what I have learned at TBN. I saw the relief valve on the spool and figured I should set it. So now I went looking for the pump relief pressure setting in the shop manual and found it.
Thanks everyone for helping me understand this.
 
 
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