Hey guys. Just a quick question. Do I need to "break in" our new 312C for a certain amount of hours? She'll be showing up tomorrow and I've got it on a 1 1/2 month job already. Also, how long does everyone cool down the turbos? I usually let the rental pieces we've rented go for at least 5 minutes, is that adequate or should I go a little longer? Thanks!
I would suggest reading the maintenence portion of the manual. Most new machines, it's recommended to change the oil after a couple hundred hours. New engines tend to grab a lot of metal filings from machining the engine, etc. As for warm up cool downs, 5 minutes at least is a good idea. -Jim
Yeah, I'm aware of changing the fluids sooner than needed the first go around due to the metal shavings, etc. We also do SOS sampling through our dealer as well. Thanks!
When you have a new machine you should warm up the hydraulics before you start digging. You can warm the hydraulics up just putting the boom through some motions. The most important thing to do in the morn is check the oil and fluids ya its a new machine but its a habit you want to get into. Before the key goes into the ignition you do morning inspection. For the engine I prolly wouldn't run the engine at high mode till you get the first oil change hours. As for engine oil its your choice but Delo 400 or Rotella are both good don't go with synthetic its more expense also you don't want to use it during engine break in. You should have a log book started in the machine and kept in the machine or at your shop. It will show the oil changes etc and other maintenance. Did you order your case of Cat oil filters see if the Cat dealer gives a discount for bulk buys and a couple air filters then have the old ones cleaned. Go to your local bulk fuel place and buy 2 cases of grease. For engine cool down 5 mins is about max you want to idle the engine all you really need to do is wait for the turbo to spool down. Longer periods of idling cokes up the turbo. You have to check with your dealer to see what they have to do for the warrenty stuff. They may have to come out and do the first fluid change and check over to satisfy the warrenty requirements.
Yeah I was reading an article about air filters in a trade magazine, they say not to blow them out?! How are you supposed to clean them?
You send them off to a company that cleans them they use viberation and electrostatically clean them. The contractor I worked for used to have filters cleaned all the time. Its cheaper than buying new ones especially when you have the larger barrel type filters. They come out clean as new blowing them out with a air nozzle on your air line doesn't get them clean you can damage the pleats. Ask your Cat dealer or they may do it themselves it will save you and your dad some change. If your in dusty conditions you will prolly be changing the air filter monthly in severe cases twice a month. You would buy 2 new filters so you have spares once the original one gets dirty send it out to get cleaned install a new one and once that one is dirty send it out. You could be doing the same with your skid and mini ex.
Ford's got some good advice. In cold weather, even after it's old, you'll also want to warm up the hydraulics to keep from cavitating your pumps, just move each control in 1/3 motions (for ex. curl the bucket 1/3 the way then back then 2/3's then back then all the way, then move to the next) at mid throttle. With it being a new machine, you shouldn't have to worry, but you might want to check the pipe plug levels on your final drives the first time, just to make sure they have enough oil in them, after that unless you see a leak, it should be OK. I do hope I'm helping and not just telling you things you already know,:yup One thing I'm really happy about with the schooling I got (at PCT) was that it instilled doing the preoperational checks on all fluids, filters, etc..., looking out for damage/leaks, and warming up the machine properly. It's second nature for me now. Also, I'd like to see photos, if possible, new machines are always good to see on the first day
For sure, I'll get some pics hopefully tomorrow. I'll be sure to check the final drives tomorrow. Sounds like I've been going about the air filter all wrong, I've been blowing the skid steer and excavator filters out. I was sure to use low pressure, but I will definately have them sent out to be cleaned from now on. I'll order 2-3 extra filters for each machine, we are in extremely dusty conditions out here, I usually cleaned the smaller machines at least once a month if not more.
Its amazing how clogged the filters get when your working in dusty conditions you will see it in the fuel consumption and you will get a little more black smoke. With the newer diesels really relying on the turbo they need a good supply of air. I also forgot to meantion pick up a case of fuel filters too.
Will do, thanks for the tips!
Worse thing that you could do is blow them out. It makes bigger holes in your filter which in turn allows more dust (contamination) into your motor. There is probally an "air restriction guage" inside your cab or near the filter itself. When you notice it starting to go into the red change your filter. Believe it or not over servicing your air filter (changing it to often) is harder on the motor than only changing it when required. Your "operators manual" should give you all the info that you need.
I was always aware that "over changing" filters and fluids lets in contamination, I always waited until the meter was in the red to change the air filters and never changed fluids before the correct hours were up.
I have to disagree here. If the machine has been working hard, exhaust gas temperatures (EGT) will be fairly high. The expanding exhaust gases are what drive the turbo, and the turbo along with the housing absorb a tremendous amount of heat. At idle speeds, EGTs are much lower and in a safe range. If operating at full load, and then shutting down after only the turbo has spooled down, the fins and housing can retain enough heat to cause damage to the bearing. By idling the machine for a length of time, both the cooler exhaust gases and circulating oil work to cool the turbo off. This time should be specified in your owner's manual, or check with your service department. If left at high temperature, the heat can transfer to the turbo bearing and the residual oil can actually burn and adhere to the bearing surface, causing premature failure over time.
The engines in excavators are really not working that hard all they are doing is driving hydraulics its not like a truck where its seeing rpm swings. The engine in the 312 I assume is a 4 cylinder it says 90hp. Your going to let the engine idle anyhow while your doing your greasing after the day is done. Greasing more or less takes 5-10 mins depending on how fast you are that should be enough time for cool down etc.
You both IMO have good points. By idling for a long time and engine temp drops you will not properly burn all of your fuel and it will start to coat the cylinders walls. I have seen much higher wear #s in oil ays. on equipment that idles more than others. Even excavators will get heat soaked when ran hard for long periods of time. And excavators might not run directly off the motor it still sees a large load from the hydraulic system. I would not idle any longer than 20mins. at a time I have noticed a little more smoke from our newer machines after taking off after idling much longer than that.
As I think meantioned by somebody find out what Cat says they will know and tell you what won't void the warrenty. The engine oil will be the biggest thing they will want something that meets their spec's.
You are right that the excavator doesn't see as much acceleration and deceleration as a truck or a loader but as for 'not working that hard and all they are doing is driving hydraulics' I would disagree with... most modern excavators are load sensing variable displacement and can absorb almost all available horsepower during heavy digging and multifunctioning. It takes a lot of horsepower to create flow and pressure thats why you hear the engine lug down when bringing in the stick and crowding the bucket and the pumps are swashed up, however the pump(s) will regulate themselves to prevent over lugging and stalling so they are far less likely to be operated at an improper speed.
With refernece to the cooling/idling issue... I think the confusion stems from the phrase " wait for the turbo to spool down". To my way of thinking, "spool down" means for the turbo to return to whatever its idling RPM is, as opposed to its RPM at engine operating speed. I can't see that being very long at all--20 or 30 seconds maybe, if even that? That wouldn't be long enough to cool down the hot spots in the whole engine, and the turbo, which is the reason for idling before shutdown. To expand on what Steve said, isn't it the fact that, once the engine is shut down the oil no longer circulates that's the root of the problem? The bearing is hot enough at any time to cook the oil, but fresh, cooler oil is constantly being supplied, so it's never there long enough to be an issue, until you shut down. At least I've had it explained that way to me. Given LT's most recent post, it doesn't seem that he's advocating shutting down after only 30 seconds of idling. LT mentions a 5 minute maximum, and I'm not sure anyone would make the case that it's necessary to idle any longer than that...
I wouldn't ever shut a engine off right after its worked a 8 hr day you do have to let it normalize the oil pressure drops down etc. What we usually do is stretch the boom out so you can get all the grease fittings start greasing get the machine grease up then go get the P/U to fuel up the machine. The excavator is turned off machine gets fueled up then its go home time.
My point was there is a significant difference between the time a turbo spools down and when it cools off. The optimum way to determine this would be to have an aft turbo EGT gauge. A turbo spools down within seconds of returning to idle, while cool down can take several minutes as has been mentioned. I don't condone excessive idling either. There have been studies done that show there is not enough heat generated at extended idle to allow complete combustion of the injected fuel and oil dilution can result. There is a happy medium between these two extremes that will help extend the life of your engine. Shut down too soon and you risk turbo bearing failure, too late and you increase cylinder wear.
Thats very good advice all round but about positioning the boom it is also good practice because: 1. As much chrome cylinder rod is tucked away as possible (it won't get dusty and rusty when buried in the cylinder tube and in Canada we don't want ice to form on them). 2. Position is generally where the hydraulic level sight glass indicates full.
everyone has excellent points. i believe all of themare true to some degree on different machines. i would suggest consulting owners manual or local dealer on turbo cool down. i know this is a whole different animal but cat rep informed us that on our Cat 8T dozer an 10 -15 min. cool down period is recommended. he went on to say that the 8T has insulation around the turbo that keeps the turbo warm longer. again i suggest owners manual or discuss w/ dealer. of course this is all IMHO.:laugh
I will offer, In my truck, 1997 Ford F-250 Power stroke diesel I have the gauges installed to moniter the EGT, Boost pressure and Trans Temp. The EGT normally runs from 400 - 600 with no load just normal driving and takes a mier 30 - 40 seconds to drop from that to below 300. on a full load where it has been working the EGT will be around 700 - 800 ( this is all Celcius) the EGT will take about 1 min to drop below 300. This is totaly different then an engine running full rpm for for extended periods of time, however the idea is still there. Your EGT drops quickly when at idle. no matter how you do your shut down the turbo will always keep spooling after u shut the motor off and will potentialy keep spooling with no oil. thats a given. It does stop fairly quickly, how ever still spins with out oil for the same amount of time weather you idle for 5 mins then shut down or 10 mins then shut down. the only thing your insureing is the EGT and that leaves pretty quick. I would say 5 mins is all thats needed. I could be way out to lunch, but thats my theory.
AS for breakin. I worked for a Cat dealership for many years and did quiet a few presales assemblies and checks. The engines have all been dynoed and run at full power for quiet a while ,so its not like older car engines where you couldnt rev them for a while. With my own ,though I still dont give them too much for the first few hours ,just out of concience. What I most certainly do is give them a good warm up before working hard. I dont necesarily sit there idling for ages ,but after a minute or so of running ,go up to a few revs and move the bucket or do whatever prechecks need to be done, then if I have to travel it ,just use 1/3 -2/3 revs until it is warm. Something I am a REAL BELIEVER in is changing engine oil early for the first service or two ,and drop the pump drive, swing and final drive oils early as well ,then go to normal service times.(always dropping the oil as soon as possible after stopping the machine so contaminents are in suspension) Another thing I always do on new machines or ones which have had hydraulic repairs done is to use high efficiency flushing filters for a while(an hour or less) to get any tiny little bits out. Sometimes if a machine has 4 hydraulic filters ,I will fit 1 flushing filter in place of a regular one for an hour or so. The filter will bypass though if you use too much implement speeds ,so I usualy only use the high effiecincy filter while at lower revs doing cleanup work, then go back to the regular filter. As for turbo cool down. For the last minute or so of operation ,the machine is usaly not loading trucks or doing productive work ,so I back the revs a bit ,then while I,m packing up my lunch bag and filling in paperwork ,giving the cab a quick brush out, the machine gets to wind down for a few minutes more.