Kubota B7510 Lift Pump

   / Kubota B7510 Lift Pump #1  

fireball71149

New member
Joined
Jun 20, 2012
Messages
5
Location
Bethune, SC
Tractor
Kubota B7510HSD
I replaced the lift pump but still do not get fuel from the output side of the new pump.
I am getting fuel to the input side of pump.
Any help would be appreciated.
Richard
 
   / Kubota B7510 Lift Pump #2  
You ARE talking about a supply/lift pump, right??>> NOT the injection pump..
Unless the cam lobe is worn to the point that its not actuating the lift pump rod.. that seems impossible..
Its just a silly diaphragm pump w/ a rod to make it move..
Did you test it before you installed it??
You could say "the heck w/ it" & install an electric pump..??
I've never heard of such a problem.. Now if we're talking INJECTION PUMP.. that's a VERY common problem..
 
   / Kubota B7510 Lift Pump
  • Thread Starter
#3  
I tried to respond yesterday but couldn't get to post for some reason. It is the lift pump and not the injection pump. It was suggested to me by a friend today that if the battery was weak it might not be turning the cam fast enough.
 
   / Kubota B7510 Lift Pump #4  
On the B7500 (and probably the B7510) there is a return line from the injectors that connects into the injection pump. If that return line has a spit in it the injection pump will draw air instead of fuel. It happened to my B7500 and was a real PAIN to find.
 
   / Kubota B7510 Lift Pump #5  
I tried to respond yesterday but couldn't get to post for some reason. It is the lift pump and not the injection pump. It was suggested to me by a friend today that if the battery was weak it might not be turning the cam fast enough.

Did you buy what your friend said?
 
   / Kubota B7510 Lift Pump #6  
The RPM will have an effect on STARTING but not on lift pump activation.. I can/you can, make the LP work w/ your hand on the work bench..
Why not pressurize the fuel tank w/ a little air inorder to get the fuel up to the inj. pump..??
Leave the banjo bolt connector loose AT THE INJ. PUMP, pressurize the tank till you get fuel & tighten the bolt back down..
Loosen the lines AT THE INJECTORS & crank till you get fuel UP THERE, then tighten.. Its called bleeding the air from the system..
 
   / Kubota B7510 Lift Pump
  • Thread Starter
#7  
Will try and see if it will work. Thanks for your help.
 
   / Kubota B7510 Lift Pump #8  
It's darn hard to get em primed sometimes. I usually just give up and pull it with another tractor.
 
   / Kubota B7510 Lift Pump
  • Thread Starter
#9  
Dwayne I might have to do the same.
 
   / Kubota B7510 Lift Pump
  • Thread Starter
#10  
I jumped the tractor off of my truck and turn it over several times and the pump primed. Thanks for the input now to bleed the injectors.
 
 
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