We are working in fine alluvial silt (raking) and the following radiator is after 5 hours. It is also contribuiting to our overheating. From what i can gather, the air intake sucks it though the spiral pre-cleaner, the particles get pushed against the wall, and the venturi (that relies on negative pressure from the exhaust) sucks the dust out from the side? Closer inspection indicates the venturi (low RPM) is blowing air (positive pressure) instead of sucking. Higher RPM, it is faintly sucking but mainly blowing. Would this indicate an exhause leak somewhere in the muffler?
It probably means that the Venturi in the muffler has been burned away. It's not uncommon in high hour machines.
Hi Nige, Thank you for your input What does the venturi look like? here are some photos down the stack and through the one way "check flap" ?
The venturi is a narrowing of the exhaust. In this case it's part of the chimney. If yours looks like a straight through pipe then you don't have one. Because the pipe with venturi is relatively expensive, it's common for them to be replaced with a piece of plain pipe and you then lose the venturi effect. It looks like you have a new check valve. If the old one lost its flap, it's possible for the exhaust gasses to get pushed back into the precleaner and melt the plastic components.
It has the end pushed in to a Y shape ... looks like it sits just above the intake pipe for the venturi ? Do you know what the part number is? as parts.cat is a pain in the ***... is it 7C-2991 EJECTOR AS ? 9tc03036 here is the inside of the "STACK"
First up, 7C-2991 is the correct P/N for the ejector for that Serial Number tractor, but that's only for the top pipe. Second, as I suspected it looks like at some time the dust suction pipe in the venturi burned up and been replaced by a piece of plain pipe. It should be centred in the outlet from the muffler and it isn't. Because the dust suction tube is part of the muffler most users fab something up if it ever burns up and that's where the suction effect gets lost if the shape of the OEM design is not faithfully copied. As I understand it the top end of the dust suction pipe should leave it right in the centre of the three protrusions you see inside the exhaust tube (7C-2991 ejector). The exhaust gas is compressed as it enters that reduced diameter section of the ejector tube and as it passes that point it then expands creating a lower pressure. This is right at the point where the dust ejector tube terminates so the low pressure acts as a suction on the top end of the tube and sucks the dust out. Therefore it's critical exactly how far you push the ejector tube on to the connection in the top of the muffler to get those two mating parts to line up correctly. See if the diagram below makes it any clearer. Also check the connector between the turbo and the muffler. On the turbo side (where you say it's loose) there should be a spring steel ring to seal the exhaust gases at that point. Maybe it's missing..?
OK, Your chimney "pushed in to the Y shape" looks correct. As Nige said, your ejector tube isn't centered in the venturi which will contribute to the ejector not working efficiently. BUT reviewing your first pic, there's crap on the outside of the radiator. Your machine was shipped with a plain blower fan so, IMO, something is wrong there.
Thanks guys, just need to find a picture on what it is supposed to look like. The fan behind the radiator is a huge ass push fan. It displaces a lot of air... It pushes the dirt up 15 metres in the air Pretty certain it's a larger cfm fan and it has yellow blades. Mentioned to us it was an upgraded fan
Hey mate, can't realy comment on a dozer like nige and Cmark- they know there stuff! But I have 2 2388 headers with a cyclone system than looks identical to what your pictures show. Every year we pull them apart ( drill rivits out- is all plastic) and blow them out cause they are always full of chaff and rubbish internally. These might be different I have no idea but the ones on our headers always give trouble and they only probs do 500hrs a year max. Mabe you have pulled them apart? Just an idea if you haven't.
My question would be if that's the outside of the radiator *** does the inside look like..? Have you looked or got a pic..?
Ill grab a picture tomorrow of the "inspectiaon area"...... well its not really that big here is the two coolers in the way, the crap is a fibre from a plant known as calitropia... its so fine it gets into the filter... the FAN sucks from the sides and blows out the front... With the trans cooler and a/con radiator... there is very little room to even check. Their is a side access panel on the left hand side (2-4 inches wide) and I can get a air hose behind there to blow it out. That radiator was before I cleaned it out, total of 5 hours work that day. This soil is a very fine silty soil with muscovite (mica) which is a pain in the backside as it is quite abrasive.
Sandblasted radiators (and fan spiders)........ that brings back memories of working in the desert, none of them good ones.... Have you considered moving the aircon condenser to the fender and having a separate fan setup for it like newer tractors have..?
That sounds like a good idea... do you have any photos so i can have a look at it ? The air filter (for the air/con) on the top of the enclosure is also an issue i need to fix, the evaporator is clogged from dirt, i may just block it off with a plate and recirc in the cabin. It's blocking up to the point its ice, then the heat melts it and you get a nice pool of water in the cabin... not fun
You'll maybe need to take a look at the setup on a D8R, the D8N as standard only has the radiator-mounted aircon condenser. The fender-mounted air conditioner condenser was an option on 9EM-prefix D8R machines and probably on other D9R models as well. The condenser mounts on the RH side behind the hydraulic tank and has 2 electrically-driven 24V fans. The attached photo is a 10T but the setup is the same on all models. The downside is that the hoses for the aircon are much longer.
Usually severe ice buildup on an evaporator is caused by the operator turning the A/C thermostat to it's maximum cold temperature. This causes the compressor to never shut off and causing ice buildup because the small amount of ice formed in normal cycling cannot melt. When the system is slightly low on freon can also cause this. Mike
There should be a freeze switch on the evaporator that does not let it stay below freezing for very long. Any vehicle AC should be able to run on any setting indefinitely without appreciable icing.
We used to get rid of those old pre cleaner setups and just install the Turbo II pre cleaners. I extended the suction piping to above the hood and the coarse stuff would fall on the hood and not get caught by the engine fan and blown through the radiator. We never had exhaust getting sucked into the intakes anymore either.
Yair . . . frysie . You don't mention where you are but a few notes from a bygone era may be pertinent today. If you are raking with big tractors it suggests decent flat going and with good lights and working the wind there is no reason they can't be worked at night. A few degrees ambient makes a difference. I used to run midnight till eight and four to midnight. You need to keep the belly guards clean and good airflow around the sump. Forget the air and get set up with a water-tanker and a pump that will put about 50 PSI on a 3/8"nozzle and be prepared to wash them out twice a day . . . a proper wash up and down each row of core until the water runs clear and run them hard and bring them up to temp and dry before you put them back in the dust. If you have been using air the initial wash could take hours and, if there's any oil around, a good detergent will help. Once you get them clean though with swing away guards it will take less than half an hour. Once the timber is on the ground, the engine side screens can be removed. Made a difference even though ours were mesh on the eights and twenty ones. Cheers.
Thanks nige , I'll see if I can round up some diagrams
Last job I worked before retirement I had a young fellow running the 988F on the opposite shift. It was in late fall in western Washington. He would turn the AC thermostat all the way up and then turn the heat up. When I came to work in the AM all the glass would instantly fog up due to all the water on the condenser. Told him about it, he stopped doing it and the problem went away. Maybe the F's didn't have the freeze switch. Mike
Hi Nige, photos as requested, we moved the exhaust so it is 25mm below (CAT SIS doc) the narrowest point of the flute and she sucks well now. The venturi is working now and I can hear it sucking...
My D8R trash dozer and D8T have the AC condensors on top of the cab at the rear that is another option also unfortuently they have to be taken off to be trucked anywhere.
See how critical it is to get the exhaust ejector pipe in the correct vertical position with respect to the end of the dust suction tube..?
War story: During the Vietnam conflict, the CH-54 Flying Crane cargo helicopters came in with turbine engines without air cleaners; in that environment, engines were requiring replacement on an average of about 50 flight hours due to dust/sand-caused wear. If you can imagine a 9,000 shaft-horsepower fan, you can imagine the dust and sand they could raise, as well as their being a huge impediment to the pilots' seeing the landing spot (read, "impossible to see outside the cockpit while landing"). Somebody designed what is called an "Engine Air Particle Separator" that utilized the vacuum of the engines to suck air through a bunch of small round devices about two-inches in diameter and mouinted on a box that would cause the air to spin within the device and the particles of dust and sand, being heavier than air, to be slung by centrifical force to a constantly-operating dumping mechanism while the now-particle-free air flowed into the engines which could then routinely last their however-many hours until normally-scheduled replacement. Just didn't know whether this could be a solution for working in such adverse conditions. Neill
Yair . . . I thought Tarhe Drivers description above was pretty much how a pre-cleaner works. I take it this venturi carry on is to save having to empty the pre-cleaner bowl? What do they think a bloke is going to use on the cone clutch of the winch? Cheers.
Frysie, This might help you. It's an illustration & a photo from a machine where the suction tube and the venturi are all part of the same ejector tube. Despite the fact it's not all that clear the photo might help you to see the relative locations of the two.
Thank you all, realised the exhaust part ( with the flutes) were way to high for the venturi to even work. Filter is not even dusty and has solved alot of our overheating issues