I have a Bobcat 7753 skidsteer with hydraulic pressure problems. Sometimes it takes 3 or 4 starting attempts before the pump activates. When this happens, I get an HP1 warning so I shut it down and try again. When the pump finally starts to pump, it is sudden and full power and the machine functions properly. Fluid seems to be clean and full. Filter has few hours. The belt seems to be tight enough...Any suggestions?
Hydraulic Pressure, slow to be applied
- Thread starter jyrrock
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J_J
Super Star Member
- Joined
- Sep 6, 2003
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- 18,952
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- JACKSONVILLE, FL
- Tractor
- Power-Trac 1445, KUBOTA B-9200HST
What does HP1 actually mean?
Maybe you have a suction leak, and air is getting in the system.
Maybe you have a suction leak, and air is getting in the system.
That's possible because I do have a small fluid leak as well. But, with a suction leak, would I still have complete power as soon as the pump "suddenly" kicks in? (It runs with full power and and full speed as soon as I hear that pump start pumping.)
The manual shows that HP1 means, "SHUTDOWN, pressure". I get a beep-beep-beep when this warning shows up and in a few seconds the machine automatically shuts down if I don't shut it down myself.
-I really appreciate your help.
The manual shows that HP1 means, "SHUTDOWN, pressure". I get a beep-beep-beep when this warning shows up and in a few seconds the machine automatically shuts down if I don't shut it down myself.
-I really appreciate your help.
wdchyd
Elite Member
:thumbsup:.........with a vacuum leak it could lose its prime and lights up when purged......
J_J
Super Star Member
- Joined
- Sep 6, 2003
- Messages
- 18,952
- Location
- JACKSONVILLE, FL
- Tractor
- Power-Trac 1445, KUBOTA B-9200HST
Recheck all fittings going to the input of the pump. Since the leak goes from out to in, you may not ever see a leak. If you tee a gage in at the pump outlet, you can see in an instant whether you have any pressure. If you could put a vacuum in the suction line, you would also get an indication of low suction. If you are sucking air, you should see it some where, maybe tank. If the suction line is good, the pump should start pumping with even one revolution.
For explanation, take a 2 cu in hyd pump, and fill with fluid, until both hoses and motor are full. If you turn the pump one complete, 2 cu in of fluid should come out of the pump.
Starving the pump and sucking air is not a good thing.
That indicator is a good thing, as it is probably sensing no pressure.
For explanation, take a 2 cu in hyd pump, and fill with fluid, until both hoses and motor are full. If you turn the pump one complete, 2 cu in of fluid should come out of the pump.
Starving the pump and sucking air is not a good thing.
That indicator is a good thing, as it is probably sensing no pressure.
wdchyd
Elite Member
Tough to find them......if a suspect area shows you can pack the area in question with clean grease and see if symptoms persist......
Yes (Belt drive). I first thought it was slipping but it seems to be tight enough. Now that I think about it more, if the pump is not spinning freely enough, it could be slipping anyway.
Another question for J J: If I have air sucking, would the bucket drop faster than normal if left raised off of the ground while not running? I left it up for a couple of days without propping it up (was going to prop it and lift the cage, be got pulled away) and it took about 2 days for the bucket to drop to the ground when raised about 8 feet and not started again.
Another question for J J: If I have air sucking, would the bucket drop faster than normal if left raised off of the ground while not running? I left it up for a couple of days without propping it up (was going to prop it and lift the cage, be got pulled away) and it took about 2 days for the bucket to drop to the ground when raised about 8 feet and not started again.
