KOMATSU D20A-5 ADVICE AND INFO.

[Thumbs Up Farm]

I could use some help with advice and info. Here is the story.

I have an opportunity to purchase a Komatsu d20a-5 Dozer for $4500.00. It has 4200 hrs. on it. This machine has been setting for about three years. I also have the opportunity to try it before I buy it. I am concerned it will become a money pit, too small to do much work, and cost me a lot of lost time trying to make it serviceable.

I checked all the fluids for water and correct levels, checked the air filter for rats, mice, and dirt dabbers, I charged the batteries and cranked the machine over by bumping the starter to make sure the engine wasn't seized or full of water. I cranked the engine over several times with the starter while listening for any unusual sounds or binding. Everything sounded good.:thumbsup: Finding that it cranked over easily I decided to attempt to start the engine. I attempted to open the throttle in order to start the engine. The throttle was stuck and would not budge.:thumbdown: So, I disconnected the cable from the engine bracket and moved the throttle lever on the injector pump forward off of the kill position. I cranked the engine and, to my surprise, it started right up:dance1:. Smoked slightly at first but cleared up quickly.

Next I tried to put it in gear, but apparently the main clutch was stuck. Having no way to kill the engine from the operators seat, and being close to valuable property that just wouldn't look the same with a run away dozer plowing through , I decided not to try to force the gears in an attempt to free the clutch. I sprayed the throttle mechanism (as well as other controls) down with PB Blaster to try and get things moving again and left for the day,

After returning to spray the throttle cable and linkage daily for about a week, I was still unable to move the seized throttle cable. So, not wanting to spend any money on a machine that may not be worth it, I decided to attempt to free the stuck main clutch. So, I set the throttle to the kill non-run position, put the dozer in gear, pushed in on the clutch pedal and tried to crank the engine. It worked! The engine cranked while in gear with clutched pressed. So now the main clutch is no longer stuck. :cool2:

Next, I started the dozer, checked the blade hydraulics/controls, put it in gear and pulled forward, then backwards. But, apparently both steering clutches are stuck since pulling either steering lever bogged the engine down and produced no turn. Being unable to control or open the throttle more than a fast idle, I am unable to determine whether or not the steering clutches can be freed. So, I ordered the throttle cable, which cost $90, and the great sucking sound of my hard earned dollars being sucked into the money pit begins.

Now I am waiting on the cable and will replace it a soon as it comes in. I hope that I can get the RPMs up on the engine and pop the steering clutch/brake that it will release and begin to work.
I would like to know if anyone else has been through a similar event and what kind of results you had. I would like to know how and what kind of adjustments are available on the clutches/brakes. Also, I would like to know general opinion or advice about this particular dozer and deal.

Thanks!

 

[Thumbs Up Farm]

Update on my progress;

I got the new throttle cable in and changed it out today. I immediately tried to get the steering clutches to free up but had no luck. I was able to turn the dozer slightly, probably just from the brakes without clutches releasing. The brake on the right side did not seem to apply very strongly. It may be worn out. I noticed the hydraulic oil is low. I don't know what kind of oil is used in these machines and have no book. Does anyone know?

If I cannot get the clutches to release, then this may be a deal breaker for me. I plan to try again by cutting some large blocks of wood, placing them behind one track at a time, and backing up on them while pulling the steering clutch release lever. Maybe this would force the clutches to release??

Any input from some more experienced people on here would be appreciated.

 

[ultrarunner]

The only time I had a stuck/frozen clutch it did free up after about 10 minutes running through backwoods/rock.

Maybe I was lucky...

The price seems like a deal if you can use it and get it working without having to do a teardown...

Several here have similar and have been very pleased.

 

[SimS]

Below is a link from another forum I frequent. Very helpful folks. Your mention of low oil level and this link's mention of plugged oil strainer may offer some help for your situation. You might try servicing the hydraulic system's fluids, filters and screen before going further into the machine. Good luck. SimS

Komatsu D20a-5 main clutch removal..

 

[Thumbs Up Farm]

Thanks for the replies! I had already read the one forum about the clutch. But, best I could tell, this one referred to automatic/fluid type clutches whereas all of mine are dry. I am new to the dozer scene, but it seems that most all of the machines with dry clutches have issues with the clutches sticking if left setting for an extended length of time??

Today, I made a little more progress. I used a large wooden block behind the track and backed up on it while holding the lever for the side that the block was on. I was able to get the right side clutch to release and can now make right turns. This is significant because the dozer was left setting close to a house, a driveway, and several vehicles which I did not want to damage. Now that I can maneuver, I plan to move the machine to a more dozer friendly environment. I can get more aggressive with it then and try to get the other clutch free.

Please correct me if I am wrong. But I think, now that the RH clutch will release, that I should be able to run against a tree while pulling both levers and cause the dozer to apply full pressure to the stuck (LH) clutch. I am hopeful that this will break it free.

I do need to change the filters and fluids, but I am wanting to make sure the machine is a least useable before I invest a lot of time and money. I need to top off the hydraulic fluid in order to use the machine. What type of hydraulic fluid do these machines use? I have been using a universal type fluid from TSC in my tractor. Does this dozer use the same thing? Also, this machine has idiot lights instead of engine oil pressure and temperature gauges. How hard is it to add gauges? Anyone already done it?

 

[GManBart]

Here's some info on the -6 and -7 units....lubricant guide etc, in case you can't find anything else.

Section for komatsu d20,21 and similar grey market dozers - Page 2

 

[Thumbs Up Farm]

Thanks GmanBart. Based on the chart they use engine oil in the hydraulics.? Guess I was expecting some type of hydraulic oil.

 

[ultrarunner]

My CAT D3 used engine oil for the hydraulics...

 

[Thumbs Up Farm]

Hello, hope everyone had a good Christmas.

I just got back to working on the dozer and discovered an anti-freeze leak. The radiator was dry when I first started looking at this machine. So, I filled it with anti-freeze prior to starting the engine and checked for leaks but saw none. It took 2 gallons to fill it up. After running the engine for a few (15) minutes, I looked for leaks and again found none. I remove the radiator cap and checked the fluid level and it looked fine there was no loss of fluid. So, I thought all was well and that maybe the previous owner had drained the system to prevent freezing.

However, after resuming work on this machine, I again checked the radiator and the fluid level was low. I checked the engine oil and everything seemed fine. So, I looked under the machine for the leak and found a puddle of anti-freeze at the front left side underneath the radiator in the vicinity of the lower hose. I also noticed a slight leak at the upper hose. It seems the upper hose clamp is not tight since I can rotate the hose on the radiator fitting. I suspect the same condition may exist on the lower hose.

There is little to no room on the left side of the machine to access the lower hose clamp. Also, just by reaching in with my hand I can feel the leak(s) what seems to be a hole or possibly a drain plug on the same side as the lower hose, but no drain petcock as I was hoping for.

Does anyone have a good picture of the lower left side of this radiator that I could look at to see what I am dealing with? How do I gain access to determine the location of the leak and determine what repair is needed?

 

[Thumbs Up Farm]

More info please,

Today I moved the dozer to my farm. The first order of business was to find a tree to push against to free the stuck LH clutch. IT WORKED!: I can now steer the machine with either lever.:cool2:

I ran the dozer for about 30 mins. in which time I pushed down 4 small trees and two stumps. So, I am liking this machine so far. :thumbsup:

I discovered the following issues and would like some advice.

The gear shift would grind some, as if the main clutch is not releasing completely. Steering the machine took, what I think, is excessive force on the steering levers. I attributed that to the clutches being stuck and still not fully releasing. I am not sure if that is the case or not?.:confused3:
I shut down the machine and looked for leaks and rechecked all the fluids. I also tighten the tracks and greased all the fittings.

Upon checking the fluids, the anti-freeze was still full. The engine oil was unchanged. The front clutch dipstick level was a little low. The rear transmission/drive unit was over full??? The main hydraulic tank was low, (out of sight glass)?? I saw a slight leak of fluid at one end of the main lift cylinders but no significant amounts of oil.

I bought a service CD which I have been looking at. I am also looking for an operators manual.

My questions:

What kind of adjustment can/should be done to the main and steering clutches? My CD only gives instruction for foot-pedal-steering but, my dozer has levers?? Can fluid from the main hydraulics leak into the rear transmission?? Do I need to drain the excess from the transmission? How hard/expensive is it to replace cylinder seals?

So far, the comments on here have been helpful, or at least encouraging. I am making some progress. I hope I am not bothering anyone too much with what are probably trivial questions to some.

Your feedback is appreciated.