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dipper stick slow cycle

BIGDAN315

BIGDAN315

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Jan 29, 2008
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Self employed in the excavating buis and have been
On my PC 75 UU2 Kamatsu I all of a sudden experienced on the retract motion only on the dipper stick moves very slow. Timed it at 15 second as to extend at 5 sec. Does any one have any Idea what to look for ?
 
BIGDAN315

BIGDAN315

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joispoi said:
Does it have the same power as before, but just with slower movement?
Click to expand...

Has very little power and speed but only on retract motion only. Every thing else is fine. :beatsme
 
F

fast

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Location
kansas
On my cat 304 I had a problem with the boom down cycle, it was super slow to go down and wouldn't even lift the machine off the ground,every other cycle worked great, machine was under warranty so took to cat and finally figured out it was in the spool valve that controls that operation, they replaced that valve and works great.
 
BIGDAN315

BIGDAN315

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Messages
229
Location
Newark, NY
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Self employed in the excavating buis and have been
fast said:
On my cat 304 I had a problem with the boom down cycle, it was super slow to go down and wouldn't even lift the machine off the ground,every other cycle worked great, machine was under warranty so took to cat and finally figured out it was in the spool valve that controls that operation, they replaced that valve and works great.
Click to expand...

That was my first suspicion that it some where in the controls. Thanks
 
D

Dr Komatsu

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United Kingdom
The PC75UU-2 isn't a machine we have in the UK but it will be similar to oher Komatsu's.
Could be a broken spring on the arm spool ,which you could check by removing the spool caps and inspect. Check the spool moves from side to side with fingertips.
If they are ok you could swap the ppc hoses to the spool caps from side to side .If it changes over the problem to arm out fault is in the PPC circuit. Or you could swap over the arm safety sucion valves from side to side.
 
F

fast

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Location
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Thats what cat did on mine was switch the hoses around to another valve and it worked -so they replaced but before they did they tore that valve all apart and couldn't find anything wrong at all- not sure what happened with it
 
BIGDAN315

BIGDAN315

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Messages
229
Location
Newark, NY
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Self employed in the excavating buis and have been
Dr Komatsu said:
The PC75UU-2 isn't a machine we have in the UK but it will be similar to oher Komatsu's.
Could be a broken spring on the arm spool ,which you could check by removing the spool caps and inspect. Check the spool moves from side to side with fingertips.
If they are ok you could swap the ppc hoses to the spool caps from side to side .If it changes over the problem to arm out fault is in the PPC circuit. Or you could swap over the arm safety sucion valves from side to side.
Click to expand...

How do I know which valve is which LOL ? What are ppc hoses ? Are they from the joy stick controls ? Guess I better find a manual on this machine. :tong
 
F

fast

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Messages
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Location
kansas
On my cat, on the right side under the hood there is a bunch of valves stacked side by side bolted together with a lot of hoses connected to them, on the cat they have colored tie straps all over the hose ends so you can trace them out, you might be able to have someone stand by those valves while you operate that function and be able to hear which one it is- I don't know how to post pics so if you want to PM me your email i will send a pic of those on my machine the dealer sent me when my machine came in.
 
D

Dr Komatsu

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United Kingdom
You can tell which spool is which by following the arm cyl hoses from the cylinder back to the valve block. PPC hoses come from wrist controls.
 
uffex

uffex

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Jan 23, 2012
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Lincoln UK
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Good day
It may be a good starting point to make some measurements, please see attached.
Kind regards
Uffex
 

Attachments

  • H2 CheckOut ArmCyl 1 .pdf
    1.5 MB · Views: 8
  • H2 Measure flow & speed.pdf
    1.3 MB · Views: 6
uffex

uffex

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Joined
Jan 23, 2012
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Location
Lincoln UK
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Good day
Please see attached for dash 2 you can easily check if yours is the same follow the main lines from the cyl;inder.
Kind regards
Uffex
 

Attachments

  • Kom PC75 MCV.pdf
    1 MB · Views: 2
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