Komatsu D20A-6 ?

[MasterG]

Im new to the forum. I have enjoyed so much of this thread. Very educational for me. Dont want to offend anyone and hope no one takes it the wrong way I’m only seeking some help. I’m not allowed to post yet as I am new to forum so I’ll get to the point. I’m the proud owner of a d20a-6. My tilt cylinder is leaking pretty bad and Two lift cylinders aren’t looking to great either. So I have decided to repack all five cylinders and I am hoping for advice and if anyone has a part number or cross reference for these cylinders. I’ve called around some hydraulic repair shops and it’s pretty expensive at 75 per hour with an average of hour and a half per cylinder barring any trouble. Not saying it isn’t worth it, it is of course, but it’s expensive for me. So I’m gonna hopefully learn how to do this myself. I’ll be happy to share my endeavors would love to contribute to this thread in a positive way for others. As has been done for me. Thanks and best wishes everyone.

 

[Patriot RAM]

Hey guys, I need to re-pack the cylinders on my D21A and I'm looking for the best way to identify the model and locate the serial number. I think it's a D21A-6, but not sure how to confirm. I've located serial numbers for the transmission, hydraulic valve assy, fuel pump, etc, but for the life of me, I cannot locate the s/n for the machine itself. I think it may be covered by layers of paint, but I'm not sure. Would it be possible for one of you owners to tell me the exact location of your serial number, and possibly shoot a photo of it for me? I've searched and searched. Thank you so much!

 

[krackerjack9]

Can you provide pictures of what hydraulic lines you tapped into for your remote on the back of the dozer, I got a ripper all set up and for over a month I cant figure out how to make it work, I just dont understand or im using the wrong parts im at a total loss, if you can help I really appreiciated George krackerjack9@sbcglobal.net

 

[GuglioLS]

George,
Need to install a new double action valve between the pump and OEM blade valve. Remove the hose and hard line from the pump output all the way to the input of the blade valve. Install a new double action valve. Get a new hose made to connect from the pump output then into the input of the new valve. Then get a new hose made from the new valve back to the input of the blade valve. Basically all you need to do is put the new valve in series with the blade valve. In other words - Output of pump to new valve, output of new valve to input of blade valve. It's a simple in series hydraulic circuit. You will have to remove the floor plate, seat plate and seat riser plate to access to the blade valve hydraulic input fitting , and to remove the hard tube access to remove the valve input fitting really tight, but doable.

Why are there 6 hoses connected to what looks like an electric solenoid operated valve? normally 4 hoses, in, out and the two cylinder ports.

BTW the ripper construction looks really great. Nice work! Is it all home made? if not please share the source for the parts you used.

 

[krackerjack9]

Thanks for all the input and advice - I made a counter offer, it was accepted so we closed the deal.

Lots have happened since I took delivery - here is an update:

The biggest concern I had with the purchase of this machine was that it would not turn right when you pulled the right steering break lever. I read over the manuals I got and discovered a simple adjustment for the steering breaks. So I pulled off two bolts removed a small cover, tightened up the adjustment bolt a few turns and Shazam! The steering now works perfect !
Here is a picture of my "new" (dirt cheap - used) Dozer at it's new home:

After making the break adjustments to both sides to make them even, I tested out the steering, here is a video of it doing a figure 8. The dozer is amazing, I have never driven or operated a dozer before. It will now turn on a dime:

I will need to drain all the fluids and replace the oil & fuel filters. I think this thing uses about 25 gallons of oil in various places I also need to reverse the cutting edge on the blade. After that, I think it will be ready to go. Oh need to set the valve lash - I doubt this has had any of the required scheduled maintenance.

Engine-----------------8 liters 15W40
Clutch case---------- 6 liters 10W
Transmission case 16.5 liters 30W
Hydraulic reservoir 33 liters
Final sprocket drives Left & right 12 liters ea (24 total)10W
Total 87.5 L or 23 gallons of various oils.
Fuel tank 60 liters (15.8 gallons)

All in all, this was a smoking deal, and I am fortunate to have found this little machine. I will need to practice on flat land so that I can develop skills in operating it safely and efficiently. The purpose of all this is to use it to cut a road to access the other 3/4 of my property.

Larry

Final drives should be 30wt not 10wt, about 2 gallons each

 

[krackerjack9]

the 6 lines, are one in and out for up and down for each side so thats 4 then other two are to the ripper up and down thats 6