• Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

Section for komatsu d20,21 and similar grey market dozers

GuglioLS

GuglioLS

Well-Known Member
Joined
Apr 5, 2009
Messages
59
Location
Edgewood, NM USA
Occupation
Electronics Field Service
75bronco said:
D21a-7, what is the little black dial just to the right of the key? Thanks

Does anyone know where i can get an owners manual for this thing?

Thanks
Click to expand...

How about a picture? Perhaps the headlights? My headlight / rear leamp switch is to the left of the key, again my machine is a D20A-6
Ebay and google searches will turn up a manual of sorts. All are out of print so expect a copy with terrible pictures for big bucks.

Larry
 
RRRancher

RRRancher

Well-Known Member
Joined
Jun 3, 2011
Messages
113
Location
Henderson, Texas
Occupation
Retired
75bronco said:
D21a-7, what is the little black dial just to the right of the key? Thanks

Does anyone know where i can get an owners manual for this thing?

Thanks
Click to expand...

Here is a picture of my D20A-6 dashboard. I don't know if you are talking about the same thing as what I have an arrow pointing to, which could very well be located elsewhere on your dashboard, but this is the display for the glowplugs to let you know they are working.

1-D20A6_Dash.jpg

I have an owners manual and service manual for the D20 and D21 A and P version 6 machines. but not the version 7. I actually have an extra service manual that I am willing to sell for 20 bucks (the cost to have it copied) plus shipping. It is a copy of a copy, so there is a little reduction in the quality of the print and drawings, but still very readable.
 
7

75bronco

Member
Joined
Jul 13, 2012
Messages
6
Location
Robbie Billings
I think the knob i am reffering to operates the headlights. My headlights do not work so i need to run things down with a volt meter.

Sounds great about the manual. I sent a email.
Thanks

RRRancher said:
Here is a picture of my D20A-6 dashboard. I don't know if you are talking about the same thing as what I have an arrow pointing to, which could very well be located elsewhere on your dashboard, but this is the display for the glowplugs to let you know they are working.

View attachment 93161

I have an owners manual and service manual for the D20 and D21 A and P version 6 machines. but not the version 7. I actually have an extra service manual that I am willing to sell for 20 bucks (the cost to have it copied) plus shipping. It is a copy of a copy, so there is a little reduction in the quality of the print and drawings, but still very readable.
Click to expand...
 
RRRancher

RRRancher

Well-Known Member
Joined
Jun 3, 2011
Messages
113
Location
Henderson, Texas
Occupation
Retired
Check just inside the engine housing area by the lights to see if the wire is unplugged. On mine, there was an inline connector about 10 or 12 inches away from the light that would allow you to remove the light without cutting any wiring. I removed both of my lights as they were both damaged and when I pulled on the wires from them going into the engine housing, the connector pulled out of the hole that the wire runs through and I was able to just disconnect it there. Maybe yours has come unplugged accidently. Oh wait, you have a version 7. I bet your lights are mounted internally instead of outside like mine. Nonetheless, you may find the same connector.

I'll check my email when I get home this evening.
 
I

illinoisboy

Well-Known Member
Joined
Sep 16, 2009
Messages
146
Location
Greenup
Occupation
contractor
Hey guys I know it's on here but I need a hydraulic filter number preferably Napa if somebody has one thank you!
 
J

John25mm

Active Member
Joined
May 6, 2012
Messages
30
Location
Hanahan, SC/Sardis Ohio
Does anyone know if the hydraulic system on a D20a-5 is stackable i.e. can I add another hydraulic circuit to the system? I want to make a 3 point hitch to the back of my dozer and this would be the easiest way to do it. I want to be able use some of my 3 poin tools and make a ripper attachment also. Any ideas/help would be greatly appreciated.
 
g_man

g_man

Senior Member
Joined
Apr 21, 2011
Messages
321
Location
Northeastern VT
Occupation
Retired
John you could always put a diverter valve on the output side of one of your blade valves. With the dirverter in one position the blade valve contrls the blade in the other it controls your ripper.
 
RRRancher

RRRancher

Well-Known Member
Joined
Jun 3, 2011
Messages
113
Location
Henderson, Texas
Occupation
Retired
This was done by one of the guys posting on this board, and there is a pretty detailed discussion about it. I want to think it was in the first 30 or 40 pages or so, but I really don't remember for sure.

Edit: Just took a quick look and found the start of the discussion on post #510 on page 34 with the main stuff on the following pages. There are lots of pictures and details. Hope this helps.

RRR
 
Last edited:
J

John25mm

Active Member
Joined
May 6, 2012
Messages
30
Location
Hanahan, SC/Sardis Ohio
Thanks that is perfect! I have read over that and promptly forgotten it. I guess it gave me the idea that festered in the back of my mind. I have gotten some stuff from Darin(great to work with) and like I told him I am in a lovely sandy place with high temperatures right now and am working on ideas for when I get home. Now I can plan on what to get to make this project work.
I mainly want to do this so I can make a ripper for it. I am open to suggestions for other ideas to play with or things you wish you had on your dozer. I have LOTs of time to think things through.
 
g_man

g_man

Senior Member
Joined
Apr 21, 2011
Messages
321
Location
Northeastern VT
Occupation
Retired
Re: the previous mentioned valve installation.
This is written more as something to think about rather than a criticism. But if you look at the RD5100 valve specs you will see that even though it is a 3000 psi valve the max allowed pressure for the Tank Port (Out Port) is only 500 psi. This is typical of this type valve. In the above installation the out port is connected to all the original down stream dozer hydraulics. This means that when the ripper valve is in neutral and you use your blade controls the system pressure is very likely to go well over 500 psi which is a violation of the RD5100 spec.
I might add that lots of people have done it this way and seem to get away with it but alot also have developed premature valve troubles.
The "in spec" way ( I won't say correct way ) to do this is to use a Power Beyond plug in the valve which is available for the RD5100. Run all the down stream hydraulics from the Power Beyond Port which is speced for 3000 psi and not the Out Port. Add a third hydraulic line from the valve Out Port to the dozer hydraulic tank return line or to the tank itself. A little more complicated but not bad.
Something for you to research and think about.
Here is the valve spec

http://www.princehyd.com/Portals/0/products/valves/catalog/ValvesRd5000.pdf
 
J

John25mm

Active Member
Joined
May 6, 2012
Messages
30
Location
Hanahan, SC/Sardis Ohio
Not being a very knowledgeable hydraulics person I have a question or two. Do you think I could tee off the pressure side and return lines as appropriate to run the lines back to a valve? This way it would apply pressure to the 3 point hitch when I want. What I am looking for is to be able to apply a medium amount of down force that will hold there or up with the right type of valve. I would go off the blade cicuit because I don't see much use of both the blade and the 3 point hitch. The set up I want in the end is 2 double acting cylinders to be able to angle of the 3 point hitch up and down both together and up and down indipendantly to be able to angle in this case a ripper off of the horizontal. Yes techincally it would be a four point hitch but it would have the frame set up to take 3 point hitch impliments.
 
g_man

g_man

Senior Member
Joined
Apr 21, 2011
Messages
321
Location
Northeastern VT
Occupation
Retired
Well that is a fairly complicated question and I am not sure I understand it all but in general you can do what ever you want.
Keeping it simple, your dozer has what is called an open center hydraulic system (vs closed). If you learn the basics of that type of system you will see that all the control valves need to be in a series loop. You cannot tee off to add a valve. If you want to add another cylinder or cylinders, like for a ripper or 3ph, there are two common ways to do it. (1) Add a new control valve for the added cylinder(s) and put that new valve in series with the existing valves just as was done in the previous posts above. Or (2) add a diverter valve so that you can use an existing control valve to control either the original equipment or the new cylinder(s). You direct the hydraulic flow out of the control valve work ports to drive either the original equipment or the new cylinder(s) thru a set of selector type valves called diverters which you plumb in at the control valve work ports outputs.
Each method has its pros and cons. Both methods are sound and reliable ways to add functions.
 
Last edited:
You must log in or register to reply here.
Top