Section for komatsu d20,21 and similar grey market dozers

[K5Cruz]

I've got a d21. I set the parking brake and let it sit about a week. The right side brake will not release. The linkage is stuck forward with the petal released, and it just lugs the engine down while in gear. Where should I start looking to remedy this problem? Thanks.

 

[k&g]

the one under the seat is for the transfer case theone under the brake pedal is the transmission they both use straight 30 weight motor oil and to tighten your tracks there is a small cover on each side with a bolt in it remove the bolt open the cover and pump grease in the fitting until their tight enough...

 

[Garrie Denny]

On the subject of track adjustment. How much curve should there be in the top of the track between top carrier roller and either end track wheels ? I have a fiat 70ci and only has the one top carrier roller, should it be nearly straight without and dip or have a slight dip when adjusted properly, id like to know please. Garrie.

 

[g_man]

To tight is not good. To lose is better than to tight. Don't know about your Fiat but as an example on my TD7G which has one top roller and about 6 feet of track on the ground the correct track tension is between 1" and 1 1/2" droop between top roller and front idler when the rest of the track is tight.

 

[Garrie Denny]

Thanks very much for the reply,I have a fair bit more than that (approximately80mm) between roller and front idler, rear of the roller to backdrive has about what you have described, I didnt want to over adjust,you see some photos of tracks with no droop either side and to me look way too tight. thanks.

 

[Sabo]

Hi guys im new here, i would just like to hear your suggestions ,I am working a D65EX-15 with common rail system does not start, the engine cranks but no smoke comes out, there is no active indication,all resistance in the injector are in normal range,I had already checked also the PCV 1 and 2.Thank you

 

[jeepinmatt]

Having a problem with my D21-A5. I used it to do some gravel-moving on my neighbors driveway, which is a steep hill (50-80% grade). No noticeable problems. Parked the dozer. I cranked it up a couple days later, and there was a strange whining noise. I put it in 1st to go forward, and nothing happened. Sometimes it does this when its cold, but after waiting 30 seconds or so, I became concerned. It finally moved, but very hesitantly and intermittently. I got it to a good spot and checked all the fluid levels. Blade hydraulics were a little low but, everything else was fine. I spent some more time playing around with it and here's a synopsis of the symptoms:
1. Whining noise when in neutral, but goes away when in gear
2. Moves fairly well at low rpms, can even push a pile of dirt
3. Steers properly
4. Inching pedal and brake work properly
5. Works better in 2nd gear than 1st, regardless of direction
6. If moving at low rpms, and then transitioning to higher rpms, it loses drive at somepoint around 1/2-full throttle
7. The whining noise returns as rpms climb

Anybody got any ideas? I pull the directional and inching valve off the top of the transmission and inspected it, everything looks great. Not sure where to go next.

Thanks in advance.

Never saw any replies on this, but got the problem solved. Ended up being the cleanable (wire mesh) filter element. It was an easier fix than expected. With the top covers off, take the two 13mm bolts loose at the front bottom left of the transmission. Pop the cover off and catch the 8-15qts of 30wt that will come pouring out. The filter will likely wash out with the oil.

Once I got the filter out, it was covered with grit, grime, and what looked like old gasket material from something. I sprayed it down with PB Blaster, then Carb cleaner, then water hose, then PB Blaster, then Carb cleaner. Looked a lot better so I gave it a gentle rubbing with a wire brush, then repeated the spraying process a couple of times.

Assembly is the opposite of disassembly, but make sure you put the filter in with the open end facing out. If you don't, you'll have to get a really strong magnet and pull it back out (ask me how I know). Add a couple of quarts of oil, and then run it a little to circulate everything around before topping off.

Previously, when I put it in gear, it would hesitate from 5-15seconds before starting to move. After cleaning the filter, as soon as I put it in gear, it jumped forward, and is now moving more consistently and better than ever.

Also, if you are thinking about replacing the filter, get a price first. Local dealer quoted me somewhere around $300. Fortunately they were knowledgeable (and nice) enough to tell me it could be easily cleaned.

 

[wsw]

Its a strainer so yes it can be cleaned, I got a question though. What does your neighbour drive? 50 - 80 percent grade is pretty damn steep

 

[jeepinmatt]

Its a strainer so yes it can be cleaned, I got a question though. What does your neighbour drive? 50 - 80 percent grade is pretty damn steep

A variety of vehicles: All wheel drive SUV (no problems), Rear wheel drive truck (gets a running start, spins all the way up), and Front wheel drive car (gets a running start, and doesn't spin MOST of the time), hahaha. The best part is that he is a grading contractor and has the equipment to fix it, but has been living there for almost a decade as it is.

 

[jyarbrough]

Well my little D20p-7 still does not turn left without tapping the break. So after reading all the post, I checked the drain plug on the left underneath the rear and about a quart of oil or dope poured out. I proceeded in letting all the fluid drain and then cranked the dozer and it turned perfect. So what are the next steps to fixing the problem. I am assuming from all the post that there is probably a seal leaking. Is this something I can fix and what are the steps or pictures to fixing this.

Again, thanks for all the wonderful posts on this forum, I have learned a great deal about these little dozers.

Jimmy

 

[wsw]

Garrie Denny , G-man is right. the best way to check the track tension is to move the machine forward and let it roll to a stop, prefferably have a grouser stop directly above your carrier roller. Lay something straight ( 2x4 or piece of steel ) across that grouser and down over the front idler. Then step on the track ( to remove the slack from behind the carrier roller ) if you have to and midway between the carrier roller and front idler measure from your straight piece of down to the top of another grouser. 1 1/4" would be right for a machine that size but remember it varies with the type of material you are working in ( go a bit looser with material that packs in the tracks )

 

[mbr06]

d20p-7

have a d20 key will not turn the injection pump on or engage starter injection shut off solenoid ticks when i turn key but will not turn on pump also will not turn over with key i had to unhook injection shut off and cross solenoid to get it fired any ideas?? thanks

 

[Chief Jim]

Hi Guys. I saw a post that said the Komatsu line has 1000 / 540 rpm PTO and 3 point hitch set ups. How about some photos/ prints/part numbers/ stories? I am the guy with the D3b mounting a Brown Tree Cutter. I am always open to something that could improve the idea.
Thanks,
Jim

 

[mitch504]

They don't, there are a couple posts in this thread about people wanting them, or wanting to make them, and a couple guys have.

 

[Frank Dozer]

I have a 1985 Komatsu D21A-5 Dozer. I need both the left and right track adjusters. That would be the cylinders with the grease fittings. I could also use the frames. If you want to sell them let me know. Thanks, Frank

 

[millstream]

Hello.

I have a Komatsu D21a 2 speed dozer. The cable that shifts it from neutral to 1st and second is broke. I can't find a replacement but have found the cable that shifts it from forward to reverse. Does anyone know if these are the same cables?

Thanks-Scott

 

[Frank Dozer]

Well, On my Komatsu D21A-5, I have looked everywhere for the track adjuster cylinders and found nothing. Since my cylinders leak, I either sell the machine for parts or find an inovative way to fix it. Has anyone devised a way to adjust the tracks another way? My machine only has 1800 hours and runs new. Shame to part it out or scrap it. Any Takers? Machine is in Hanover, Massachusetts Email me for a picture.

 

[FurakawaMatt]

Well, On my Komatsu D21A-5, I have looked everywhere for the track adjuster cylinders and found nothing. Since my cylinders leak, I either sell the machine for parts or find an inovative way to fix it. Has anyone devised a way to adjust the tracks another way? My machine only has 1800 hours and runs new. Shame to part it out or scrap it. Any Takers? Machine is in Hanover, Massachusetts Email me for a picture.

Just a thought.
Use a horizontal hydraulic jack/ram between the spring and front idler yoke. You would have to cut away some things or you might even come up with a simple screw and pin setup. So long as the spring is left in to move for shock take up, something could be made up I would think. Creative machining and welding.

 

[Frank Dozer]

That';s a good thought. I just checked with Harbor Freight's web site for a bottle jack. I'd have to remove / unbolt / burn off all the track adjuster frame, leave the end of the frame for that one idler. Then cut the Yoke shaft to about 6", insert that end into a short lenght of pipe, insert the bottle jack neck into the other end of the pipe. I'd need to use part of the idler bracket to hold a plate for the end of the bottle jack. Do you think I really need the shock spring?

 

[FurakawaMatt]

You will want to leave the spring so that the idler can move back with loading. A bottle jack will not work in a horizontal direction only vertical. It would take a ram like you see on the 10 ton manual wood splitter that HF sells. Or heck one of those short rams from a porta power type kit could be inserted with some way to lock it after adjusting.