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Kamatsu PC 75 bucket hitting cab.

BIGDAN315

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I am a fairly new owner of a PC 75 uu-2 with off set. Not paying attention I was curling up the boom and bucket to the upright position and was educated very fast when the bucket came down on the cab :Banghead It left a pretty good dent and cracked the window. I wouldn't think that such a thing could happen ? Shouldn't there be limits on these from the factory so this can't happen? It is and older machine, 1995.
 

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"Two-Books"

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There is one thing I have always done, and that is when operating a new or strange machine was to run the unit through a complete range of movement's to see what if any problems with interference. Especially with none factory attachment's, hammer's, hoe-pack's, wing coversions and the likes. It's a lot easier than learning the hard way and get's rid of unpleasant surprise's.
 

AtlasRob

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Shouldn't there be limits on these from the factory so this can't happen?

Sorry to hear you found out the hard way.

Many excavators have this heart stopping attention seeking habit. Any that cant achieve it straight from the factory can usually manage it once a quick hitch has been added, BUT should have warning labels in the cab to warn you.

You are not the first and sure wont be the last. If its any consolation have a look at this, I hope the damage was not as bad as the fright.

https://www.heavyequipmentforums.com/Forum/showthread.php?t=11415&highlight=hitting
 

powerjoke

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Missouri
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they'll come in the cab with you espessially if they have a pin grabber.

Blades (road graders) are the worst for interfearing with itself, you can get one of those things to tear itselft apart.

Pj
 

special tool

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Bethel, Ct.
I am a fairly new owner of a PC 75 uu-2 with off set. Not paying attention I was curling up the boom and bucket to the upright position and was educated very fast when the bucket came down on the cab :Banghead It left a pretty good dent and cracked the window. I wouldn't think that such a thing could happen ? Shouldn't there be limits on these from the factory so this can't happen? It is and older machine, 1995.


You see - this is what I was talking about in that other thread.
These things are supposed to have potentiometer systems (like mine) in the boom/stick and a computer system that locks it up.
Just so you cant go all the back and up then side swing the articulate into your brain.

Your machine has been the victim of a "genius" mechanic who bypassed the system.

Some guys just should NOT be allowed to ever lay their hands on a machine.:Banghead

Did they leave the wires and sensors up there, at least?
 

John C.

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All those articulating boom excavators are supposed to have an electronic safety system that stops that crashing feeling when you see the bucket trying to come into the cab with you. Unfortunately the systems were not designed by the manufacturers and repairing them when they got problems was almost impossible. I finally got a repair book for them a few years ago and even then fixing them was hit and miss. Most people just took the rods off the potentiometers and welded the linkage arms solid.

In yours I don't see any linkages so I suppose you will just have to live with the condition. I'm guessing that your machine is gray market and if so you got what you paid for. If not I would recommend contacting your local dealer about it.

Good Luck!
 

willie59

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Knoxville TN
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I can see the potentiometer and arm on top of the offset boom pivot pin. All that tells me is that your machine has/had the system to protect cab crash. As John stated, many times they have a problem, an owner/mech can't figure it out, and they disable the system. A Komatsu dealer should be able to repair it, but those parts aren't cheap.
 

Chris5500

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Oct 23, 2009
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Australia
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Plant Mechanic
The most famous is the O&K RH120 (the entire range) even the Terex RH120E's can (with the correct (or incorrect depending on which way you look at it) combination of bucket and G.E.T.) can touch the cab, and peel off part of the F.O.P.S (more so though sun visor/windscreen protector part).
 

heavylift

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KS
lots of them will hit.... depends on the added stuff.. plus wider buckets....
most machines have a warning label stating the fact....
 

mike69440

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Apr 2, 2007
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New Hampshire
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Still looks like a clean PC75

I have my PC75 a few months before a potentimeter crapped out and the computer was disconnected. As I have been using the PC75 to move rocks a 12- 14 T machine struggled with, and I have beat up the bottom metal of the cab pretty good by carrrying +5,000 lb rocks pinched betwwen the bucket, thumb and blade.

I've been luck notto put the bucket in the cab so far.
 

BIGDAN315

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Self employed in the excavating buis and have been
Pc 75

I have my PC75 a few months before a potentimeter crapped out and the computer was disconnected. As I have been using the PC75 to move rocks a 12- 14 T machine struggled with, and I have beat up the bottom metal of the cab pretty good by carrrying +5,000 lb rocks pinched betwwen the bucket, thumb and blade.

I've been luck notto put the bucket in the cab so far.

Mike, Yes it is clean thanks. I am a little confused as you stated you where moving rocks with a 12 - 14 ton machine and the Kamatsu is only an 8 ton machine and it's doing a better job ? Did you mean 12 -14 thousand pound machines? :confused:
 

special tool

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Mike, Yes it is clean thanks. I am a little confused as you stated you where moving rocks with a 12 - 14 ton machine and the Kamatsu is only an 8 ton machine and it's doing a better job ? Did you mean 12 -14 thousand pound machines? :confused:

Most likely not - these machines can lift way more than enough to get you in trouble.
They will get you in SERIOUS trouble over the side - not for the novice.
 

mike69440

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Apr 2, 2007
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New Hampshire
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My 17,500 PC 75

Mike, Yes it is clean thanks. I am a little confused as you stated you where moving rocks with a 12 - 14 ton machine and the Kamatsu is only an 8 ton machine and it's doing a better job ? Did you mean 12 -14 thousand pound machines? :confused:

I had about 5,000 Yards of rock & material blasted at our farm and this material was moved to build our road and site for the equipment building by a 14 T Link belt and Cat 312.

Looking at another $100K to finish was what got me to get the PC75.
The remaining rock was piled.
I have been using it for retaining wall projects and fill.
I should have got the PC 128!

http://www.tractorbynet.com/forums/projects/89163-busy-wife-weekend-12.html
 

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AtlasRob

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I had about 5,000 Yards of rock & material blasted at our farm and this material was moved to build our road and site for the equipment building by a 14 T Link belt and Cat 312.

Looking at another $100K to finish was what got me to get the PC75.

Great job Mike :notworthy I think its safe to assume the investment was well worth it.

Lovely looking spread you got there :drinkup
 

mike69440

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Why wish for the 128

The later PC128's asside from having the aticulated boom and a blade had a cab and seat that I could fit my 6'-3" old body in comfortable. Low and hig speed on the tracks and the weight would be better to dozer with also. Stumping with a PC75 is tough, plus those rock are real hard to move with the PC 75.

There is not that much difference in moving a PC 75 or a PC128, as neither can be moved with a 2-1/2 yard dump.
 

hammerdwn20

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Feb 18, 2008
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pa
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pipeline
I run the same machine at work with almost 6000 hours on it. its quite strong for its size. my boss had warned me about the bucket and the cab since the sensors on it are broken. Hydraulics have been turned up too. i just wish it had travel pedals and a little more room
 

BIGDAN315

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Newark, NY
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Self employed in the excavating buis and have been
I run the same machine at work with almost 6000 hours on it. its quite strong for its size. my boss had warned me about the bucket and the cab since the sensors on it are broken. Hydraulics have been turned up too. i just wish it had travel pedals and a little more room

I agree with you on the lack of room in the cab. I am 6'1" and 275 lbs which doesn't help I suppose..:D Other than that I love the machine for what I do. I find the zero tail swing and offset real handy.
 

komatsuman1

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Dec 23, 2009
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bc canada
i too love the 75 am in the procces of instaling a thumb and foot pedals, i have a thumb and a cyl, any ideas where to pick-up from and how to activate, any help would be wolcome. new to this forum and loving it.
hummerdwn20 how do you turn the hyd up?
 
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