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Cat 312 control pattern

JPCobra105

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Mar 22, 2008
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long island
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owner/operator jpexpress demolition and excavation
hi i just bought a 97 cat 312. can anyone tell me the easiest way to change the cotrols over to JD style? thanks for any help
 

WhyWhyZed

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Feb 14, 2008
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Canada
hi i just bought a 97 cat 312. can anyone tell me the easiest way to change the cotrols over to JD style? thanks for any help
Assuming you checked under the floor and made sure it doesn't have a pattern changer valve already....
Need to swap pilot lines as close to the control handles as possible. I think all the hoses meet at a bulkhead at the rear of the cab. Will need to follow lines and swap the 2 stick pilot lines with the 2 boom pilot lines. Don't do it at the main valve.....there are multiple spools that get shifted and drift reduction valves that get unlocked etc by pilot oil....always best to swap at cab.
Deplete the oil from the accumulator by cycling the controls (as you would for dead engine implement lowering) and vent the tank before removing any lines.
 

OCR

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Rancher/Farmer, Wildland Fire Fighter, State snowp
JPCobra105,

We have a 1997 312 BL...8JR. It only has the 2 position pattern change valve. The valve is located at the front of the swing drive. If this is the
same as yours...you should see a flat piece of metal with a big bolt head,
and a smaller bolt head. Remove the small bolt and push or pull the metal
about 45 degrees or until it lines up with a threaded hole...put the bolt you
removed in and tighten. This should give you the tractor-loader-backhoe
pattern. There is, or was, 4... yes 4, different patterns. The JD I ran was the
same as Cat (SAE). I don't know what JD's factory pattern is.

The Cat sales man gave (free) us about $500.00 worth of manuals when we
bought ours, but you should at least get an operators manual. There are a number of other manual valves... and it's confusing even with the book.

We just had a bad thunder storm, and I typed this with out an internet
conection... so it looks rather odd. Down almost an hour, I'm surprised I wasn't logged off.

Try above advice... It came in when I was off line.
 
Last edited:

JPCobra105

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owner/operator jpexpress demolition and excavation
ok. i cant seem to find a valve for the pattern changer. i dont believe it has the option. i attempted to follow the service manual to ID the pilot lines. and after a few hours of work, ended up changing the bucket and swing. not the boom and stick. does any one have an understandable schematic on the pilot lines or know another way to switch the boom and stick controls? thanks for any help
 

OCR

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Cat 312 control pattern:

ok. i cant seem to find a valve for the pattern changer

JP,
It's possible you don't have a change valve... but here are some pics. of the
location on ours... Cat 312BL 8JR. Also, I Googled... John Deere joy stick pattern... led back here to previous thread on all different patterns... even some pictures from manuals... like the ones I just took to post...:eek:...:)

Any way, here's the valve and location... maybe.
Valve close up.
DSCF0582.jpg
Location... just below boom pivot...to the right and below swing dipstick, that round thing stuck out in picture.
DSCF0578.jpg

I know this isn't much help...espically if you don't have one, and it might only apply
to an 8JR. Sorry I couldn't do better.

OCR
 
Last edited:

OCR

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JP,

This is a picture from one of my manuals of the 4 different patterns...:confused:

DSCF0587.jpg

Isn't that a mess.... 4 different ones...:crazy

OCR
 

JPCobra105

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long island
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owner/operator jpexpress demolition and excavation
yeah, i dont have anything like that. thanks alot for the help though. i think i might just go to the cat dealer and see if they have any ideas.
 

JPCobra105

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long island
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owner/operator jpexpress demolition and excavation
its the 3rd pattern you show on your sheet, that im looking for
 

JPCobra105

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owner/operator jpexpress demolition and excavation
trial and error and now i have the pattern i was looking for. thanks for all the help
 

Kroffe

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Jul 14, 2008
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Aland Islands
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Contractor
Hello all!

Sorry for hijacking the thread, but since im a new member i cant do new posts ;) .

Got a problem with a Cat 312C, one day it just started to stall when turning the rpm knob down to step 1, and lacks alot of power when using the hydraulics, but idles fine and runs well on all steps (1-10) when you dont operate any hydraulics , but specially noticeable is when lifting the main boom or lowering, and seems to be weaker when tracking bakward than when you tracking forward. Also response slow when moving the joysticks, takes a while before the throttle response, (have not been like this before)
The fuel filters are replaced with orginal cat ones, the aircleaner is cleaned . But still same problem.
My first tought was the fuel filters but that didn`t sort my problem out :(.
Second was if there was any problems with the throttle cables adjustments, but it do get a little better or worse when adjusting them, but i have no right calibration on it at this moment.


Any one have an answer on this symptoms? Or any thing to try to sort out where the problem is?

Regards,
Christoffer
 

R Glover

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Nov 29, 2008
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29
Location
Texas
I am new to this forum also and have to hi-jack this thread, I have a 1993 Cat 312. Does anyone have the lifting capicity for this machine? My operators manual does'nt give any weights other that to tell you to lift on the corners.

Thanks
R Glover
 

special tool

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Jun 15, 2008
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Bethel, Ct.
hi i just bought a 97 cat 312. can anyone tell me the easiest way to change the cotrols over to JD style? thanks for any help


I just did my 225.
The lines are NOT the ones you would expect to go to JD.
Read my thread first, the 312 is similar.:)
If you send me a pm, I will help you.
-Lutjens
 

WhyWhyZed

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Joined
Feb 14, 2008
Messages
147
Location
Canada
Hello all!

Sorry for hijacking the thread, but since im a new member i cant do new posts ;) .

Got a problem with a Cat 312C, one day it just started to stall when turning the rpm knob down to step 1, and lacks alot of power when using the hydraulics, but idles fine and runs well on all steps (1-10) when you dont operate any hydraulics , but specially noticeable is when lifting the main boom or lowering, and seems to be weaker when tracking bakward than when you tracking forward. Also response slow when moving the joysticks, takes a while before the throttle response, (have not been like this before)
The fuel filters are replaced with orginal cat ones, the aircleaner is cleaned . But still same problem.
My first tought was the fuel filters but that didn`t sort my problem out :(.
Second was if there was any problems with the throttle cables adjustments, but it do get a little better or worse when adjusting them, but i have no right calibration on it at this moment.


Any one have an answer on this symptoms? Or any thing to try to sort out where the problem is?

Regards,
Christoffer

That all points to low pilot pressure.
Change pilot filter. Check pilot pressure.
 

JS580SL

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558
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Massachuessetts
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operator
ah, were in the world would you see those top 2 patterns out of curiosity? Ive seen a 416 2 stick custom set up to match a dynahoe, dipper and bucket on the left stick and boom and bucket on the right.

Other than that Ive never seen those 2 patterns ever?
 

Komatsu 150

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Aug 17, 2007
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673
Location
Northern Illinois
ah, were in the world would you see those top 2 patterns out of curiosity? Ive seen a 416 2 stick custom set up to match a dynahoe, dipper and bucket on the left stick and boom and bucket on the right.

Other than that Ive never seen those 2 patterns ever?

According to a Japanese guy I worked with the second pattern is normal in Japan. Moving the stick forward and back to rotate doesn't seem natural in any way. He said that is the way his mini-excavator was set up.
 

OCR

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I've used log loaders with a pattern similar to that MHI... where you push the lever to make the stick come in, and pull it to make the stick go out.

Really awkward and hard to get used too....... :confused:


OCR
 

Dean Francois

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Joined
Dec 28, 2020
Messages
2
Location
Acushnet, MA 02743
Just bought an old Cat 312B, that does not have the pattern control valve changer. I am trying to change it to JD Backhoe style controls. Called the Cat tech line and was told what lines to change under the front of the cab. When I removed the front cover under the cab I found two valve controls, and I found Orange R1, and Red L1 on the most forward valve, and Green R3 on the valve just behind it, but I can not find the Blue L3 but a couple of lines where missing the color/number bands. The only one I can not find is the Blue L3, does anyone know which line that is? or where on the valve bank it is? Thanks for any help.
 
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