Section for komatsu d20,21 and similar grey market dozers

[Windsport]

Hello, This is my first post in this forum. I think I must have read through all 139 pages by now, a dozen at a time and not in order. There is so much great info in here thanks to some very dedicated members. I don't recall reading anything regarding the engine oil pressure and where the best test point would be. I have a d21p-6 and I would assume right beside the oil pressure sending unit should work there are two small hex plugs of an unknown thread pitch. I would probably just pull the sending unit and test there but it needs a special socket which I do not possess and is tighter than I dare twist on with my big channel locking pliers. So I'm hoping someone on here would know where to find an adapter for these plugs or an easier test point. Also thank you to all you posting members so far I have learned so much already from this forum I hope I might someday be able to contribute as well!

 

[darinray]

Welcome aboard Windsport... It should be 1/8" pipe thread and would come with the oil pressure sending or testing kits I THINK. Let me ask you this though.. Why are you checking it.... If your oil pressure light come on start off by changing the sending unit. just last week has a local guy worried his oil pressure was low and when I went out there I seen oil creepage around the sending unit area. We changed it and the light didn't come back on again. Keep us posted and good luck with everything...

 

[Windsport]

I guess mostly for curiosity sake. A light doesn't do much for indicating engine condition. I just bought this dozer a month ago and there are a few issues to take care of first before putting it to work. I did try a 1/8" npt fitting and it doesn't seem to fit. Comparing one of the plugs to the 1/8" fitting, the plug does seem to be slightly smaller.

 

[Windsport]

So it just got me thinking that maybe its a metric pipe thread or something unique to Komatsu. There are a few issues with the dozer and I'm just trying to decide if it will be worth spending a few dollars and time on, but if something major like the engine is in a bad state then it may not be worth it. Thank you for the quick reply Darin.

 

[mitch504]

So it just got me thinking that maybe its a metric pipe thread or something unique to Komatsu. There are a few issues with the dozer and I'm just trying to decide if it will be worth spending a few dollars and time on, but if something major like the engine is in a bad state then it may not be worth it. Thank you for the quick reply Darin.

You can go to any auto parts store and get a little set of adapters to be used to instal an oil pressure gauge on a metric engine. A lot of the Japanese cars use a metric thread that is almost but not quite 1/8 pipe. It usually comes in a pack of 2 or 3 different adapters from the gauge maker.

 

[Windsport]

Thanks Mitch! I'll phone around tomorrow and see what I can find. So far I haven't had too much luck any where else.

 

[attaboy]

Thread Identification

While engine oil ports should be expected to be a common standard, it's worth mentioning (since you're new to this machine) that Komatsu has it's own breed of hydraulic hose connections .. basically 30* metric as opposed to the common 37*. You might want to d/l this link

http://www.discounthydraulichose.com/v/vspfiles/downloadables/thread_guide.pdf​

and keep it for reference. If you really get stumped you can always snoop around in the sailing/cruising/marine forums, as these smaller Komatsu engines are actually Yanmars .. I have three Komatsu's .. all 3 have Yanmar engines. Any Cat/Cummins/Perkins fans out there .. don't snicker .. Yanmar makes diesels up to 5,000 HP.

For sure, I hate idiot lights. Anyone installed a standard mechanical oil pressure gage .. please post a pic. Cheers!

 

[Windsport]

I picked up an adapter today from a parts store thinking I had the size nailed down to a m10x1.0 thread but still a no go. They used a thread pitch gauge on my plug and determined that it is 1.0 thread, however it is difficult to tell but it looks like it is a tapered thread. Which would make it a rare one for sure (m10x1.0 taper). I even double checked with a different 1/8" pipe thread fitting just to be 100% sure as they seem so close.

Thanks Attaboy! I will bookmark this page for sure, as I've started doing with any other information I come across that may be useful in the future.

 

[Windsport]

Well I got a pressure reading yesterday 65psi @ high idle (warm). I ended up making my own adapter out of a brass 1/8" npt fitting and a 1.0 thread chaser file. I had to file it down around .010" less but it threaded in and with a decent amount of Teflon tape it doesn't seem to be leaking.

 

[matticeandsons]

Hello, I'm new to your page! I have just purchased a d21a 7 dozer and I am having a issue with machine not wanting to move when I get a load on it or after it worms up for a few minutes. I have purchased the service manual and it's saying the machine should have 844 psi but I'm only getting a reading of just over 300 on my liquid gage! Any help to point me in the right direction would be great. I have dumped all the oil and have cleaned the tranny strainer. I'm at a lose as to what I should be looking at next!

 

[darinray]

Welcome aboard matticeandsons..

Dang that is not even close to the right pressure. I have to ask though and dont' take them personally. Is the inching pedal linkage allowing the spool to be all the way out of the valve body? Is there a change in pressure readings in other speeds and or directions? Is the right oil in the tranny?

 

[matticeandsons]

I have drained all oils and reinstalled sae 30! In tranny and beval gear case. Pulled strainer from tranny( it was clean).i will check inching pedal in morning.

 

[oldtom]

Digger, Its strange that yours would have more than one master link. There is no clip or pin holding it in. I'll try to give you the proper procedure for removing it but I am sure some one can give their two cents worth too. Here is the way I have always removed track pins. Run the dozer till the master pin is on the rear sprocket and pointed down at the floor. Put a large piece of steel (heavey, I have a piece of old rail road track) lay it close as you can get to the pin, cut a 4x4 or 2 2x4 nailed together, cut it to length so it will just reach the other sprocket on the other side. I cut mine about 1/2" short so I can drive wedges in it and keep it tight. Soak your pin down with pennetrating oil, take a medium size sedge hammer, then a punch just slightly smaller than the pin. ( got a old torsion bar off a car, as it is hardned and will not mushroom, about 1ft long, then get you a piece of 2x4 about 3ft long, bore a hole through it so bar will just fit. Have a helper hold the board, with the punch pin in it and then whack it hard with the sedge. Be sure and wear safety glasses. Usually this method will work, a few of them I have to apply a little heat. If for some reason a regular pin has been taken out and a master pin has been installed. I dont think you can still get it apart. So you have to make sure you take out the master link pin. I understand that when you take the tracks off and if you take it to a track press, and if you have one pin in the middle, that they have to start at the master link and work back. (thats what the track shop told me) I am sure others ,(maybe a track shop can give you better directions) The purpose of the large steel suupport in the back is so you will not spread the link and bend it causing it to jam, and supports sprocket and other components so alot of shock is not transmitted to them. Hope this helps.

missed step one reless the grease out of track adjuster/remove cover plate screw out bolt 1/2 turn put block of wood in front of track drive forward and drive grease out to get slake /
remove grouser plate two make it easyer

 

[attaboy]

Komatsupartsbook and other stuff

Komatsupartsbook .. any experience with this Chinese vendor? I placed an order for a muffler on 6-19 and still waiting for a shipping via Fedex quote from them. I found a vendor in Japan for about twice the money ($90), but they use DHL, which totally drops the ball upon arriving at Mather (Sacramento).

Got carrier rollers from vendor in Texas on EvilBay .. the flanges are a little thicker than stock .. suggest you go with 35mm bolts. TG shipping was free on those puppies. Right side was squeaky, but as it turned out, both sides were loose as a goose, but with over 28K hours I ain't complaining.

The replacement 25 amp alternator now available on Amazon http://www.amazon.com/gp/product/B006MWFF6O will install with some fiddling .. I used a 5/8" ID by 1" long bushing as a spacer. Note that the original stock Nikko alternator has an un-keyed tapered shaft, and the Amazon offering is a keyed straight shaft, so the pulleys are Not swapable. The new pulley is not reversible (to change offset) without either shimming, or turning off some relief, but I found that factory position was adequately aligned. The pulley looks to be machine to accept either A or B profile XL Gates belts .. an A sized XL 45" fit perfectly on my D21P-5.

The "In-Cab" blade level experiment is progressing and is actually pretty cool. The sender is pretty sensitive, and does vibrate just a little, but close enough to readout the 359* to 001* I'm looking for. If you want to play around with this, get a http://www.amazon.com/gp/product/B00DS9IH0A and a 10' Cat 5 cable. A second unit for blade Level to the Planet (along track axis) is not installed yet .. on the ToDo list Next task is a pad for a 20K gallon bladder tank on the side of the mountain, where normal visual ques (and butt level) for leveling are highly compromised.

As I believe mentioned in another thread, the Battery Tender http://www.amazon.com/gp/product/B002DTV172 is the way to go for battery maintenance.

Hope some of this stuff is helpful, especially for the new owners/members. Cheers!

 

[RFlow]

Hi, Guys

I am new to this forum and need some help with a Komatsu Dozer D20p-5. The serial number is #58134. I don't have the manuals for it and don't even know what year is it. I have some experience as a mechanic helper but never worked on a Dozer before.

My friend purchase this dozer a year ago and never did anything with it. I borrowed to do some work at the ranch. I put new batteries and it worked fine, but after several uses I started experiencing problems turning right, then it doesn't turn either side. It goes forward and back with no problem. I have read some info on this site and I am going to remove the seat to check the steering clutch housing on both sides and make sure there is no water or oil in it.

Yesterday I drain the oil on the side two drive axles. I also drain the gear fluid and that one came out with a light gray color and more watery. I check the transmission deep stick and is not even marking any oil.

What type of oils do you guys recommend. Can I use SEA 30 for axles, gear and transmission or should I use different for each individual. Also how many gallons is require for this job. Thanks Rick

 

[dblaneyfan]

Here is a service manual for a D20P-5, maybe it will help: http://speedy.sh/Jwd6S/SEBM0101D00.PDF

Best of luck

 

[Smogger82]

Is anyone familiar with Mitsubishi dozers?

And if so, what's your opinion on them? I've owned Cat, Deere and Case, but don't know the track record of Mitsubishi. Any feedback is appreciated.

 

[sakhoney]

well Hope this works

 

[sakhoney]

OK it does - hello to all - have just read the entire thread over the past 2 days. I have a d20 and its been a great little machine. I just hope now I don't start to have these clutch problems I read about here. Anyway - you guys on here are great - plus I find Drays post from front to back. Seams he's the one that really hung in here. My 2 cents worth on all ya'll wanting a 3 point hookup. Google search a hitch adaptor 3 point setup. There out there. Then go back to around page 30 and see Larry's post on hooking up the hydraulics to function the thing.

 

[sakhoney]

weld on a 2" hitch like Larry's and away ya go