Hi everyone, I operate a 2016 Cat 140M, in the last month I have been final trimming a pad running north south whenever I run south fumes enter the cab from the roof airconditioner inlet top back left corner ,depending on wind direction normally from the northeast. My biggest concern about this is if I can smell exhaust fumes there has to be carbon monoxide entering the cab as well. i got our mechanic to block off the inlet and no more fumes. Now my question to any other Cat 140m (may happen on other M models as well think cabs are all the same design ) operator have you ever had this problem? any comments
I would say, ‘Extend the exhaust pipe.’
wouldn't really make any difference unless you went to an illegal height, also why would a company make a machine that this could happen
What's the S/N of the 140M.? Need to see what it's equipped with in the way of heating & A/C. Lots of options in the catalogue. I would suggest that you don't go accusing Cat of having designed something bad into the machine until a) it's clear how it was originally equipped and, b) it's certain that someone hasn't been getting creative with maintenance of the cab ventilation system.
Is that exhaust pipe one piece or is its a slipped on tip? Wondering if it has been shortened? If things are running right, the level of CO is pretty low, I mean you will get the stink and a little soot but shouldn't get any measurable CO. Are there any other exhaust leaks?
Again the Serial Number (there are 12 different models to choose from, it would be nice to narrow the field to one) will show how it was originally equipped. That's where everything should start from IMHO. Good point about the possible exhaust leaks though.
Actually Australia... CO and exhaust leaks are likely the least dangerous thing in any 500 meter radius. I'd really wonder if a tier 3 engine even makes above the 50ppm CO that's allowed for 8 hour exposure.
Diesel fumes in the cab would get annoying real fast! Might be wind related so maybe modifying the exhaust pipe would help.
There's a lot of things to check before starting to talk about modifying things IMHO. I'll be honest and say this is the first time I've heard a complaint of the smell of exhaust fumes inside the cab of a Cat M Series grader in the 10+ years I've been around them.
I don't know about cab machines but on open ROPS dozers fumes can be a problem if the wind is right. Sometimes just turning the outlet on the exhaust pipe in a different direction helps. I'm curious what direction the fan is turning. I put a suction fan on my skid steer to get more heat in the winter but it didn't last long. It certainly gave more heat but unless the machine was operating room clean you got the fumes from everything in the cab.
Show us some pictures, please. If you are really worried about carbon monoxide, you can get a one the size of a credit card and put it in your machine. That’s what we have at work. You could go with a straight exhaust pipe and a rain cap or move the A/C intake to a different location.
I guess I don't recall a roof mounted air conditioner on a 140M. Is this a factory installed unit or a Red Dot someone installed? A photo might provide some better information.
John, that pricked my ears up as well. However I'm not sure if the OP means a roof-mounted AC unit or is referring to the air ducting for the heating and A/C. As other posters have pointed out photos would help.
Serial number plate from my machine, now please tell me all you think you know from that other than guesses and assumption's
One piece original equipment exhaust no leaks, not shortened, not lengthened .your quote about measurable CO is that backed by FACT or just your thoughts?
Again is that fact based or an option
The safety dept is getting a CO monitor this coming week to check levels, not modifying a bog stock machine as this shouldn't happen , again stock its how it comes from factory air intake for these things is a hole in the roof back left hand corner, which draws air down into outer cab filter, then is piped internally ( all factory )
It is not a roof mounted system it is the intake for the air-conditioner that is positioned on the roof as it came from the factory
Is your belief that exhaust is entering the cab based on fact or opinion? Cause it sounds like opinion at this point.... There are lots good guys on here just trying to help out. And I'm pretty sure Nige can get alot more then guesses and assumptions off a serial number.
When 3 different operators can smell fumes in the fully sealed cabin with air-conditioner on its Fact, if you can smell fumes gases are present Fact, levels unknown at this point ( The OSHA PEL for CO is 50 parts per million (ppm). OSHA standards prohibit worker exposure to more than 50 parts of CO gas per million parts of air averaged during an 8-hour time period. )
This is indeed strange. I'm somewhat familiar with M series graders. We've had a dozen or so thru the shop in the last year and not one workorder/complaint about exhaust fumes in the cab. I don't have much time at the moment but I'll see if I can dig up something.
Thanks mate it is a strange one our mechanic is sort of scratching his head too
Does the A/C have a recirculate mode?
That Number gives me access to information regarding how that specific machine was built, including exactly what options were installed on it out of all the options that are available. I don’t deal in “think”. When I get on to a PC tomorrow I’ll download the machine arrangement and post it up. The arrangement will have details of the AC, among others, so it will be possible to determine exactly how it was built. Knowing what it has is the first step in trying to figure out what the problem is. Like 92U3406 I’ve been around M Series graders since they first came in the market getting on for 15 years ago and this is the first time I’ve heard of symptoms like the ones you are experiencing. But there’s a first time for everything. A request. Please try to keep it polite. There is a wealth of knowledge and machine experience on this forum. You came here looking for answers and people will genuinely try to help you as much as they can. Remember that we’re not there with the machine, so a load of questions to the person who is there are the norm when dealing with a case like this. Please be patient and try to provide the necessary information to help you get some answers. Are the fresh air and recirculating air filters for the AC the standard parts and approximately how often do they get changed.? How many total hours does the machine have on the clock right now.? Could you please post a photo of the inside of the cab taken from one of the cab doorways looking towards the rear showing the louvre where the smell of exhaust gas is coming from. While you’re at it one from outside showing the fresh air intake on the rear cab roof as well please. A final shot before I head for my pit. I’ve re-read all your posts again trying to get a feel of why you posted, specifically some of your replies, and I can’t help but get the feeling that you came here to try to get ammunition to support a litigation against an organization or an individual because of a perceived or real danger to someone’s health. If that is the case please say so now before we waste any more time on this. If not feel free to set me straight and we’ll carry on regardless.
Your Final shot is so far off the mark mate not interested in that this is a health thing, i have been operating graders for 38yrs and this is the first closed cab machine i have ever had problems with operated 24m,16m, 14m and 140m and so many other models and brands .every filter on the machine is genuine all filters changed as per manufactures specs by mechanics, total hrs 3500 of machine.
I wasn't trying to offend but in my experience it's not usual to come across an operator on the other side of the World from the US who is familiar with OSHA standards for something relatively obscure like CO exposure. I did a brief trawl for any reports of odours in cabs (exhaust or otherwise) and all I came across was references to machines used in landfill applications, so there will be no magic bullet on this one. The as-built machine is in the attachment. The key is the second line, 439-4922 Regional Option Arrangement. That is an option specific to Australia that opens up to reveal the Cab Arrangement which in turn opens up to show the Air Conditioner Gp specific to that machine. Now the possibilities have been narrowed down to one. Thanks for providing the hours. I was wondering if the machine had high hours that maybe higher levels of fumes might be a potential cause - but that's ruled that out. Back to filters again - sorry. There are two Part Number options for the circular fresh air filter. Can you ask the fitter which one is being used in the machine. I suspect I know what the answer will be but I would like him to confirm it. Filter change interval. There is no recommended change interval in the manual. It's a "When Required" item because every job site will be different as regards dust and other contaminants. Can you ask what is the frequency in hours/weeks that the filters are changed.? Lastly, can someone stand behind the machine when the engine is being run at High Idle in neutral and see if they can smell exhaust being pushed out of the back of the engine compartment by the fan.
All good i hear where your coming from ill show this to our mechanic on Monday will also get filter numbers ,filter as per required like you stated at present its not dusty at all so its like hours all depends on dust conditions Thanks for your help
A few more questions that have come to mind since I penned the above........sorry it's kind of a personality trait of mine. Also just to let you know that I'm going to be away for a couple of days starting Monday afternoon (Tuesday morning in Brizvegas), so comments/suggestions in response to any answers you give might be a bit slow in coming. Obviously this is the only machine that is giving problems but is it the only M Series grader on this particular job site.? If there are others on the site I take it they are not experiencing problems.? Has this particular grader ever worked anywhere else before the current job site and were any problems ever reported at previous operating locations.? Anything that you can think of that might give rise to weird swirling winds or something like that on the job site you're at right now.? Again, so many questions but unfortunately you're the only one in this discussion who is actually there and you have to be able to describe what you can feel, hear, see, smell, etc, to help others try to help you. P.S. I'd still like to see those two photos I asked for before if it's not too much trouble. Finding root cause is no more complicated than to keep eliminating possibilities until whatever remains, however impossible it might seem, must be the truth.
Admittedly I know nothing about the M series graders, But has this one had anything added or removed from the cab since it was built? Handrails, strobes, flood lights, etc? Could be some partially hidden "mis- drilled holes in the HVAC area?
Another daft idea (thanks RZ, it was when I read your post about the possibility of unwanted holes) that needs at least checking/eliminating. Is the external aircon fresh air filter element installed correctly.? By that I mean are all the seals/spongy bits/whatever (that force all the incoming air through the filter instead of allowing some of it to go round the element) in good condition and installed in the correct location..? Not trying to pick faults, just throwing ideas out there for your fitter. If there's anything you or he are not sure about, snap a photo and post it. I've had a word with our shop this arvo. We have 8 x M Series (16 & 18) here, the oldest has about 40,000 hours on it by now. The aircon boys just looked blank at me when I asked them had they ever had an exhaust gas smell reported by an operator. The answer, a resounding no. I'm having them check with the other crews and will follow up later.
Regarding my post #30 I got chance to dig into the fresh air filter for the aircon (LH side rear corner of cab) on one of our 16M's this afternoon. See the photo below - sorry it's a bit fuzzy. Now unless your 140M has something on it that is not shown in the Parts Manual the external air entering the filter housing is sucked from the space directly BELOW the cab through the duct on the right of the photo (red circle). Add to that the hydraulically-driven fan is a pusher type that sucks air from the front of the machine through the engine compartment and then blows it out of the radiator at the back of the machine. So with the fresh air intake being far below the level of the exhaust outlet and the general direction of airflow being from the front to the rear of the machine that makes it even more baffling how the exhaust smell could enter via the AC system. Last thought. The rubber seal (Blue circle - screwdriver pointing to it) between the filter housing and the inside of the cab wall. A long shot I know but maybe if that seal was out of position fumes could enter the cab through the gap between the filter housing and the cab wall, especially as your OP mentioned fumes in the LH corner of the cab
Now here's an interesting thing. Part of the Australian Cab option are these rear vent windows located in both upper rear corners of the cab. Has anyone checked that they are sealing sufficiently well..?
Finally to RZ's post about holes. We have all sorts of stuff on our machines from Dispatch systems to additional lighting to comms radios to whatever. Here are a few random shots of the top corners and roof of the same grader just to give a few ideas of what you might be up against.
Nige your last picture is the factory box for a Communication Gp. the line with ???Is just a captive hole for a bolt. Under the box is just the cab roof
yes first thing we checked both are sealing there like new
Our mechanic is pulling everything apart today( rain day) as per Cat schematics drawings diagrams and these suggestions looking for something hopefully will have an answer tomorrow
Nige's post got me thinking. The fan is supposed to pull air to the rear. Is there a chance the fan's spinning the wrong way and pulling air thru the rad, rather than pushing it out?
That's what I thought earlier or if the fan has a self cleaning feature where it reverses. I put a suction fan on my skid steer for more heat in winter and it just stunk the cab up.
No self-cleaning reversing feature Dave. The fan works in one direction all the time. Even if the air flow from the fan was reversed I'd expect it to blow a smell of hot oil/fuel fumes/etc towards the cab rather than a smell of exhaust. Looking at the illustration below it seems far more logical (at least on the face of it) for exhaust gas to be entering the top of the cab at a fairly high level above ground through an "opening" of some sort when the wind happens to be in a certain direction rather than being sucked in via the aircon system but I may be wrong.
Maybe it's JD graders that reverse the fan for cleaning. I thought maybe an exhaust leak under the hood but I don't know if the exhaust pipe is directly attached to the muffler. On my 931B the pipe on the hood is not attached to the manifold. The muffler exit blows into it but it's a smaller diameter with no mechanical connection. There is black from the exhaust on the back of the rad.
Directly clamped to the top of the muffler. I already went down that rabbit hole.
Yes, JD graders auto reverse the fan. I think maybe the newest M series do too. Mine is set to reverse every 30 minutes for 30 seconds. If I'm really paying attention I will hear the noise. If in dusty conditions and moving slowly I'll notice dust blow past the cab. No odors or other changes. Also, JD cabs are pressurized. It would be impossible to get anything into the cab without sucking it thru the filtration system. JD's cab fresh air intake is under the roof at the back. It's no more than 2ft from the exhaust pipe. Are Cat's cabs not pressurized? And if they are, wouldn't it be impossible for the smell to enter thru a hole or leaky gasket? Only place that could happen would be a failure to seal in the air intake system? Anxious to see the answer to this. I suspect it's going to be an example of the K.I.S.S. principle. Some very simple explanation that we all are looking way over the top of.
Our North American based 160M has those little vents on the cab so it’s not just an Australian thing. Anybody take an opacity reading from the exhaust ? Maybe it’s making too much smoke.