KOMATSU D20A-5 ADVICE AND INFO.

[ultrarunner]

Great news on getting the steering free...

I think working it and keeping an eye on fluids and temps will only help...

Dozers especially don't do well sitting around... and more so when exposed to the elements.

 

[Thumbs Up Farm]

Thanks! Yeah the steering clutches were a real show stopper. Getting them to work again was not easy. I totally agree that they shouldn't be left sitting unused, same thing applies to all equipment. This particular machine was setting for at least three years and outside to boot.

I used the dozer for about two hrs. yesterday with no issues. We had a lot of rain last week and the ground is really rotten. So, I was able to push up a lot of stumps and trees which made me like the machine even more and,, made me feel a little better about all the time and money I have been spending on it. I am getting to use the machine for free right now, since I am making improvements on it. Unfortunately, I have put in more hrs. working on it, than working with it.:laughing: My next step is to change the engine oil and filter and try to stop the small anti freeze leak.

I filled the hydraulics to the center of the sight glass before using it yesterday and noticed, after running for about an hour, that the fluid level had gone past the top of the sight glass. My only guess would be that the level rose because of temperature?? Does over filling cause any damage?

The temperature gage doesn't seem to work. It never moved after running for nearly 2 hours. Any ideas on why? My main concern at this point is availability of parts. How hard are parts to get for the Komatsu D20A-5?? I mean, if I shell out the money for this thing, am I going to get a few months down the road and have a 9000lb boat anchor because I can't get parts??

 

[ultrarunner]

The only time I had guage trouble is when mice decided to build a nest and made a mess of things... I tried the Bounce Fabric Softener and it must have worked because the mice did not come back..

Guess the fluid got warm if all the hydraulics were at the same point of extension before and after.

My sight gauge was a couple of inches and it would go up after a few hours of work.

 

[GuglioLS]

I have a D20A-6 that I replaced the Steering clutches and breaks on, check page 15 of my thread for that project. Not easy but doable as a one man job. It took about a week on and off. Most undercarriage parts are available on e-bay such as track rollers, sprockets, track and the likes. Also the Steering clutches and breaks are off e-bay as well. As far as hydraulic cylinder rebuild, I had two of them done by a shop. It cost 800 bucks to replace the rods and seals for two cylinders. Dozers are massive black holes for money. With that said mine is a very expensive "hobby" dozer but they sure can come in handy. If you need specialty parts a Komatsu dealer is your last resort, not many are obtainable through those channels but the ones that are will be so high priced it would be cheaper to have a new part made from scratch.

Your question about the hydraulic reservoir sight glass - the level will vary significantly between cold and hot, plus is the dozer perfectly the same level as the last time checked? I see no harm in under or over filling the hydraulic reservoir within reason plus or minus a quart or two.

I think you mentioned something about having to pull the steering levers out what seems like a very long way to get the breaks to catch. That is an easy adjustment. look at the back of dozer just above the steering clutch case on the left and right sides you will find a small cover held on with two bolts, remove the bolts and pry off the little cover, underneath there is an adjustment bolt for the steering break bands, tighten those up a quarter to half turn at a time then recheck the pull distance on the steering lever. My guess is yours are rusted in place as my were, dont spray anything in there as it will drip down on the break bands and clutches. Check page 13 of my thread for a picture of the break band adjustment access.

The more you work that machine the better it will perform.


You might read through this entire thread. I documented allot of maintenance and repair....
http://www.tractorbynet.com/forums/construction-equipment/99717-komatsu-d20a-6-a.html?highlight=



Engine-----------------8 liters 15W40
Clutch case---------- 6 liters 10W
Transmission case 16.5 liters 30W
Hydraulic reservoir 33 liters 10 W oil
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)

I wish you all the best with with your dozer. Those little 40HP Komatsu dozers are a nice tough little machine for around the homestead.
Larry

 

[Thumbs Up Farm]

I worked the machine for another 2-3 hrs. today. Pushed out 6-7 good sized trees (6"-10"). This has definitely sped up my farm clean-up efforts and so far the dozer is working fine.
I think the temp. gage may be ok. I checked the engine temp just by laying my hand on the block and it was barely warm. Also, I ran my tractor today for an hour or so cleaning up the logs and tops from the trees I pushed down and feeding cows. The temp gage on it never came up either. I guess the cold weather is the reason the gage hasn't moved

Thanks Larry, I had already read your posts and looked at your pictures. They were a big help. I really appreciate you taking the time to add all that info.:thumbsup:

I plan to do the brake adjustment pretty soon. I wanted to get some wear in on it first to try and clear any rust that is in there and give it room to fall out. According to my CD I am supposed to tighten the brake band to a specified torque, and then back off 4-5 turns. My CD shows foot pedal steering clutch adjustment but has nothing on the lever clutch adjustment. I am wondering if I need to adjust anything on the steering clutches prior to adjusting the steering brake bands???

I have been trying to get "My Komatsu" account set-up so I can get more info. but with the holidays, I have been unable to contact the right person. The main clutch on this unit doesn't always seem to completely disengage and I get some occasional grind when shifting gears. I suspect the inertia brake band is worn out. I have tried to adjust the band but the adjustment is either frozen or bottomed out as I am unable to tighten it. Maybe I need to adjust the clutch pedal/linkage on the main clutch also??

I have been checking a few places for parts and I think you are right about the pricing being cheaper to just have new ones made. The only price I have gotten on the inertia ban is $150. That seems terribly high for a small piece like that. Fortunately, I have pretty good machining and fabricating skills so I am considering replacing the pads myself if needed.

So far, I really like this machine. I very much appreciate the posts of you who have more experience in such things than I and am sure to check back here often.

 

[GuglioLS]

..... The main clutch on this unit doesn't always seem to completely disengage and I get some occasional grind when shifting gears. I suspect the inertia brake band is worn out. I have tried to adjust the band but the adjustment is either frozen or bottomed out as I am unable to tighten it. Maybe I need to adjust the clutch pedal/linkage on the main clutch also?? ..........

My thinking is if the machine is stopping when the clutch is depressed then the clutch is completely disengaging. The final shaft still spinning when clutch depressed is fluid coupling between the clutch and plate (wet clutch). The inertia break band when properly adjusted will stop the output shaft from turning when the clutch is depressed allowing gear shift without grinding. If I remember correctly the specification for the inertia break band adjustment is the shaft should stop turning withing 2 to 2.5 seconds after depressing the clutch. Based on your observations and statements thus far plus - "Fortunately, I have pretty good machining and fabricating skills". I get the impression you have already figured all this out and will have it fixed up like new in no time.

 

[Thumbs Up Farm]

My thinking is if the machine is stopping when the clutch is depressed then the clutch is completely disengaging

Thanks Larry,
My thinking is that maybe the clutch linkage is not adjusted correctly AND the Inertia brake is not either. These two are connected on the same shaft and I am thinking that my first adjustment should be to the clutch pedal linkage and then the inertia brake. I am having the same thoughts on the steering clutches and brakes.

One thing that got me on the wrong train of thought was a technician at my local Komatsu dealer who told me that the main clutch was a dry clutch the same as the steering clutches. The main clutch was stuck when I first started working on the machine. I was able to free it by putting the machine in gear, pushing the clutch, and bumping the starter. Upon the engine cranking while in gear, with the clutch pressed, I started the engine and was able to shift gears and move the dozer for the first time in 3 yrs.

Now, I have some gear grinding issues especially when I don't get the pedal pressed all the way down while shifting. Shifting is better the longer I work the machine. So again, my thought is to adjust the clutch pedal linkage first. But, now that I realize that this is a wet clutch and that heat has an effect, is there something I should be looking at hydraulically first?

I had read on one of the forums about a screen that covers the pick-up tube for the clutch hydraulics but I don't know where the screen is located, how to access it, or if it even exists on my machine. The CD I have does not show it at all.???

I do plan to remove/rework the inertia brake band if necessary (meaning as last resort). My CD says the wear limit is 2.7mm. Just by looking at it, without measuring, it looked like it still had plenty of wear left, so I am hopeful that I can remove it, free the adjustment threads, and put it back, without pad replacement.

I want to make all the adjustments/repairs at once while I have the floorboard plate off. But, right now, I don't know exactly what I need to do, and in what order, once I get back in there. Maybe, if I get the hydraulics and linkage set properly the inertia band will be corrected as well??

I have never replaced pads on a brake before. I would like to know what kind of adhesive, pad material, and rivets I need and have those on hand before I attempt to recondition the band. Again, this would be after I remove it and confirm it is beyond it's wear limit,, and all other adjustments have been made.

 

[GuglioLS]

Now, I have some gear grinding issues especially when I don't get the pedal pressed all the way down while shifting. Shifting is better the longer I work the machine. So again, my thought is to adjust the clutch pedal linkage first. But, now that I realize that this is a wet clutch and that heat has an effect, is there something I should be looking at hydraulically first?

The clutch is operated in a traditional manner by direct mechanical connection of the pedal linkage to a yolk and throw-out bearing. A wet clutch simply means it is submerged in oil with oil resistant friction disks. This arrangement significantly increases clutch disk life.

I had read on one of the forums about a screen that covers the pick-up tube for the clutch hydraulics but I don't know where the screen is located, how to access it, or if it even exists on my machine. The CD I have does not show it at all.???

Inside the clutch bell housing is what Komatsu calls a "main clutch pump" This is a bit misleading in that pump actually provides the hydraulic fluid pressure to disengage the steering clutches when the steering levers are pulled. That pump does not operate the main clutch. There is a suction strainer located at the back of the clutch bell housing accessed by removing the lower skid plate, then removing 4 bolts and extracting the strainer. Drain the clutch fluid first!

I do plan to remove/rework the inertia brake band if necessary (meaning as last resort). My CD says the wear limit is 2.7mm. Just by looking at it, without measuring, it looked like it still had plenty of wear left, so I am hopeful that I can remove it, free the adjustment threads, and put it back, without pad replacement.

The inertia break and adjustment is an integral part of the main clutch pedal, I can pretty much guarantee there is more than enough adjustment available to stop the main drive shaft. I suspect you have got to break free the threaded rod and all 4 nuts that are frozen up to get that band tighter so as to stop the main drive shaft when the clutch is depressed all the way.

I have never replaced pads on a brake before. I would like to know what kind of adhesive, pad material, and rivets I need and have those on hand before I attempt to recondition the band. Again, this would be after I remove it and confirm it is beyond it's wear limit,, and all other adjustments have been made.

Four small pads held on by rivets only. Order part # 101-11-15141 from Komatsu or Anderson equipment. Anderson Equipment Company - Your Source for Quality New, Used & Rental Construction Equipment


Steering Clutch Pump strainer:



Inertia break:

 

[Thumbs Up Farm]

Wow! Thanks Larry ! This helps a lot.:thumbsup: Your knowledge on these machines is very much appreciated.

I assume you got the parts break down photos using "My Komatsu"? I have got to get my account set-up and will work on that today.

Based on your understanding of the clutch pump/hydraulics, is it possible that fluid from the main clutch pump could be transferring into the rear transmission reservoir? I have checked the main clutch fluid level which is low and the rear trans is over full. I have added oil to the main clutch and have noticed oil leaking at the rear, under the drivers seat? I am thinking maybe the oil is being forced out of a vent of some sort in the rear trans under the drivers seat. I plan to drain the excessive from the rear trans. However, if there is the possibility of cross leakage, what might be the cause?

Thanks again for the great info.

 

[GuglioLS]

I assume you got the parts break down photos using "My Komatsu"?

Yes once "My Komatsu" account was set up I was able to copy and paste all available illustrated parts list for the entire machine. It took a while but I got every section.

Based on your understanding of the clutch pump/hydraulics, is it possible that fluid from the main clutch pump could be transferring into the rear transmission reservoir? I have checked the main clutch fluid level which is low and the rear trans is over full. I have added oil to the main clutch and have noticed oil leaking at the rear, under the drivers seat? I am thinking maybe the oil is being forced out of a vent of some sort in the rear trans under the drivers seat. I plan to drain the excessive from the rear trans. However, if there is the possibility of cross leakage, what might be the cause?

From what I understand the only places that fluid can leak into is either the outside of the machine (under the seat is a likely place) OR worse the steering clutch / break cases one on the left, one on the right. I do not see a way the clutch pump fluid could get into the final drive transmission.
The Steering clutch / break cases should be completely dry, the final drive transmission is in the center and divides the two halves. Under the final drive there are three drain plugs, the center is the final drive, the left and right are for the steering clutch / break cases. If you remove the left and right drain plugs for the steering clutch cases there should be no fluid in there. Maybe a bunch of rust and dust.