Komatsu PC 220-5 Low tracking/walking power

[d4dozer]

Hi,

I recently purchased an old PC 220-5 excavator. The old girl has 11000 hours on it and besides rust here and there appears in good condition.

All digging and swinging functions work well and have plenty of power.

The one small problem is the machine lacks power when walking / tracking. It feels like it is struggling - whilst the motor is revving fine, the tracks don't seem to have much power. It walks ok on 100% level surfaces, but the smallest incline sees it struggling. A friend who is an operator used it on the weekend (I did not mention the problem to him) and he said "its a great machine, but lacks a bit of power when walking", which says I an not imagining things.

When the tracks are lifted of the ground (by using bucket sideways) the tracks turn fine.

Both tracks and been checked and are not to tight, they were backed off slightly to be on looser side of the correct adjustment. I have checked the oil level in both track drives and they are fine. Tracks are in reasonable condition and all other oils have been checked.

The machine is still very usable, but I don't want to ruin it, or end up giving myself a huge repair bill by doing damage. So I was wondering
1) if I continue to use it is it likely that I can do further damage
2) what the likely issue is - hopefully something simple I can replace myself.

Thanks

 

[John C.]

It sounds like the cut out or TVC valve function has drifted down some and needs to be adjusted back to spec. A general hydraulic tune up includes checking and adjusting if necessary the pilot pressure, jet sensors for negative control, both stages on the main reliefs and then the cut outs for each pump and finally the TVC pressure.

What you describe likely won't do any harm if left alone. The cutouts and or the TVC just back off the pump output a bit when high flow and pressure work together to pull more horsepower out of the engine.

 

[d4dozer]

John C - thanks so much for your response.

Whilst I am by no means a qualified mechanic, I like to do whatever I can myself to the machines. Do you know were I might find the procedure I need to go through to do this? Is it something that someone with an ability to read technical explanations could do or is it something best left to the experts?

cheers

 

[John C.]

I could show you once and you would think how easy it is. All the descriptions of the process are filled with jargon so the first time you need someone show you where to plug in the gauges and which sets of screws need to be adjusted by what you are interpreting while watching the gauges. If you have a book, find the gauge ports first. Then you will need to learn which set of valves on the main control valve is which and then the control valves on the pump.

The final issue is that your machine is pretty old and may have the usual wear and tear inside all the cartridges on all the valves. Screws get rusted tight, springs get weak or break and some of the control pistons get sloppy in the bores and let some of the control oil leak by. That is the interpretation of the gauges that I'm talking about.

Do some studying and feel free to ask questions here.

Good Luck!

 

[d4dozer]

Thanks again John C

First of all it seems I need gauges......Is this a few hours works or a days work - for an experienced guy. Here in Western Australia the cost of heavy machinery mechanics is prohibitive because the of the mining industry, many are FIFO (fly in fly out) to the mines and earn extremely well. If it is only a couple hours work then it might be worth bighting the bullet and paying to have it done. If it is a days work it will run well over a thousand dollars to get someone and it makes it worthwhile in investing my time and money in gauges etc.

cheers

 

[KWD]

Dash 5, IIRC, Drop the plate under the cab then move the travel pedals and see if they are activating the travel switches, there is one for each pedal and they can be adjusted

 

[John C.]

It takes two 6,000 PSI gauges, two 600 PSI gauges and a 1,000 PSI gauge. The two high pressure gauges are for main pressure and there should be a plug on each where the output hoses go to the main valve. I'll have to find a photo to show where the two 600 PSI gauge hook into the pump.

 

[d4dozer]

Thanks both John C and KWD, I will check the foot pedal adjustment while I am at it and start the hunt for gauges! cheers

 

[tctractors]

On the Dash 5 excavator with knackered track power you need to firstly re-seal the centre joint (rotary coupling) these seals start to by-pass at around 7'000 hrs and are easily replaced, then as already quoted there is travel switch points under the pedals that usualy wear out or stick, so check these by removal and lube up and test they are working with a continuaty check, they usualy effect the dig power if failed, after you have done these repairs/checks if you still have a fault check the hydraulic tank filtering then check the pilot pressure only with a low set gauge 1'000 psi with the safty lever set to work then reply back.
tctractors

p.s. the pilot pressure is the first point to check on any fault test, but your trouble will be in the rotary coupling, it just pulls off its pillar then after the seals are fitted it needs a whack with a hammer to knock it back on the shaft.

 

[d4dozer]

Thanks TCTractors.

I will have a play on Sunday, it seems that the first "easy" approach is to check the pedals, even if they are not the problem a lube and check will ensure that simple part is ok. I will have a read of the manual to find out were the rotary coupling is. I suppose I should buy a new seal before pulling it apart.....I assume it is an O ring?

cheers

 

[tctractors]

The rotary coupling is a manifold that enables the top works to swing on the carbody unrestricted and still allow oil feeds to the track motors, there is a stack of seals involved that come in a service kit, this will be your most probable cause of your poor tracking troubles, the switch job under the floor has more effect on the top works so check them by all means, but your trouble will be in the seal area on the coupling, its easy to re-seal and just pulls off its pillar after the bolts are removed, the highest pressure on an excavator is the track power so if the rest of the chariot is working O.K. its not a pump issue.

tctractors

 

[John C.]

Don't mean to be contradictory but if a Komatsu walks straight in high and low and up an incline there is nothing wrong with the swivel. Likewise on a 200-5 there are pressure switches on the pilots and not manual micro switches on the pedals. The only thing to check on the pedals was to make sure the dirt hadn't packed underneath them limiting their travel. I've never gotten a kit when repacking a swivel, always had to order the parts individually. When a swivel goes bad on these monsters usually only one direction of one track and the opposite direction of the other track gets weak. That's why the machine veers to one side. Replacing the packing is an easy job that can be done in around 4 hours give or take a problem or two. I have pulled out more than one center section of the unit only to find out the packing rings were intact. Bad swivel packing will show up in the suction strainer in the tank. The rings used to be either blue or white in color. They were different than cylinder packing. As I recall there were six packing rings with backup rings and an O ring on the top cap.

Travel is the function that pulls the most horsepower out of the engine and the issue that always cropped up with that style of hydraulic system. Springs get weak over time which lets the performance slip. The first function where this can be felt is in the travel, especially when traveling up an incline. If the machine is walking straight, especially up an incline but just slow or seems to have no power, the only parts needed are the ones broken when loosening them to make adjustments.

Get a book and do some studying. Once you understand the components and the way the system works on your model you will know all the Dash 5 machines. They were the same from a PC120 to a PC1000.

 

[d4dozer]

Wow all that is really interesting,

I have just had a small play with the machine. I note that the left track has less power than the right when stationary and used in isolation, that is it almost stalls while the right does not, however if I go straight, and use them both together both work and there is no pulling one way.... So the power comes back to the left hand track when the right hand one is used. The power is definitely way down going straight, but not preferential if that makes sense.

I note that there are no oil leaks which is good.

Will do some more reading this evening.

 

[tctractors]

Firstly John C. not wanting to whip a dead horse, but in the U.K. the 210-5 was the common thing the very few 220s,around usualy had the "N" title and used on demolition work, the 180s' had the pedal switching fitted the 210s' did not but had the 2 speed travel switch and the straight line travel control valving, your comment about the swivel joint seal kit not being listed is not realy the case as Komatsu struggle to offer support for current build euipment in the U.K. so to ask them for parts for a 20+ year old excavator would be at best described as pointless? but we do have a very good Komatsu O.M & non O.M. dealer called Kedgworth that you can ask for a "Swivel Joint Seal Kit" and you would get the parts no trouble and for less than half the costing that Komatsu think they are worth, on the function that pulls the most H.P. out of the engine without having P.R.Vs' going off would be the stick out function, dash 5 excavators are very scarce to see now I cannot think of any of my customers that have 1 tucked away, they worked very well and would always be thought as the Rolls Royce of excavators in their day
tctractors

 

[d4dozer]

TC tractors, Komatsu in Perth WA are not interested in small guys like me, to the extent that they would not give me a price/availability on a window latch, despite 5 phone calls and 3 emails, I had to go eastern states to even get a price. Your tip about Kedgeworth is worth its weight in gold! I will do a search on the net to find them.

 

[farm]

d4dozer, I have been following this thread with interest for a couple of reasons, firstly cause you're in WA like me and also more importantly you've bought an old PC220-5 as well. When I got ours I didnt have a whole lot of luck with Komatsu in Perth either but when I contacted the Komatsu guys in Geraldton (my closest decent sized town) they seemed to be miuch more approachable for a bloke with one old machine. Just out of interest where did you get your one from? We have had a good run with this one but have only put about 80hrs on it with the only problem being leaving a hyd hose up a tree.... After that experience I dont think I'll be getting Pirtek to make me up a hose from a part number again... that stung the wallet a bit.

good luck

Steve

 

[d4dozer]

Farm - I got mine from a guy in Welshpool, he had two of them so I had a choice of two, both with similar hours. I got a batter bucket and trench bucket included. The guy who sold it to me was a really friendly fellow named Adrian, he has even been so good as to come out and have a look at my machine, but doesn't think there is an issue. We have put on about 50 hours so far. I have gone over everything closely because I want to keep the machine in good condition, but this tracking problem needs to be fixed.

It is interesting about your comments about Komatsu Perth, they are singularly disinterested in an old bloke with an old machine!....Whilst it is no excuse, the demand from the big mining companies makes us an annoying nuisance.

I will keep my eye out for a local mechanic, but my previous experiences have been all bad, but that's another storey!

cheers

 

[farm]

Well now I know where the other one went! I got the second of the choice of two you were talking about. I got a trench bucket a GP bucket and also a batter bucket, and a heap of scrap steel that I built a fixed thumb out of. He certainly is a happy bloke isnt he. On ours when in high speed, one track moves slightly slower than the other but as of yet it isnt a big issue, well not big enough for me to pull anything apart yet anyway. When did you buy it?

steve

 

[d4dozer]

I bought mine in November, I thought the one you bought smoked a small bit, had a bit more wear on the tracks and slack in the turntable. I thought yours had less rust and the cab in yours was in better condition than mine. Mine also had a dent or two I thought. The one I bought also had rock breaker fittings. The aircon in mine did not work, but it ended up being a poor earth and the need for a re-gas. I got a reputable air con company (the initial installer) to give me a quote and he said $5k plus GST, so I got a second person to look at it and it cost me $300 after fixing the above.

It was a hard decision which one to take, but it sounds like they are both ok for their age. What were your thoughts?

 

[farm]

yeah this one does smoke a bit, but the oil hasnt moved on the dipstick in 80hrs, maybe its in the injectors? not sure, but not too concerned. The air con in this one also wasnt working because of a dodgy earth. It probably needs gassing to but still blows cold air most of the time. The tracks are getting out towards the end of their adjustment but at this points its not worrying me. The slack in the turntable I'm not sure about as I have nothing to compare it with. The hour clock on this one says 9000 hrs but Adrian thought it had done more than that. We replaced the main bucket pin when I made the thumb, the one that was in there was completely rooted and the other pin on the bucket isnt much better but for what we are doing with it we'll manage. I sealed up the gaps around the radiator a bit better than they were which improved the cooling a bit. In any case I am pretty happy with this machine for something to use occasionally on the farm. Transporting it is the biggest issue for us, sort of on the lookout for an old busted arse low loader at the moment.

Good luck with it

Steve