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actvd@bigpond.com

TD14A suck or blow?

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While getting familiar with my TD14A it has been running a little too warm after working for a while, today while it was running I noticed that the fan was blowing air forward instead of pulling air through the radiator like I assumed it would.

My question is, I have heard that some fans are reversible, what is the point in doing that? Surely if a radiator has an effective shroud, then it should be pulling air through the radiator instead of pushing air through it?

Can someone let me know what is the correct way to have this set up?

Regards, Tony Brown

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Should pull air through the radiator, if you run it in the hot weather only then you might want to leave it the way it is.

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well it should be pulling air through the radiator ...being a old machine as they are ..you may have to check things like the thermostat.is the radiator internally blocked?.are the radiator fins blocked with dirt/debris,is the water pump doing its job etc ..worst case scenario would be a head gasket or cylinder head problems

cheers ken

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LOL Ken...the air is just going the wrong way. All that can be is someone put the wrong fan on it or deliberately put fan blades on there to push it instead of pull it.

D9G you could change the fan blades to push or pull, my dad got tired of freezing his butt off co one winter so he changed it to pull air...changed it back at lunch since he was roasting by then.

Far as I know to changed the air direction on the 14 you need to put a different fan on it.

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It should cool the engine either way.Most old dozers push air out (summer fan) and the fan that suck air back (winter fan) are generally too hot for the operator to stand in warmer weather.

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Also a pusher fan kept most of the dust and debris out of the radiator. Normally dozer fans push. With a puller fan all of the stuff that comes over the top of the balde gets pulled up against the grill or worse, through the radiator. The reversible ones could be changed to pull and warm the operator in the winter. Modern dozers have an electronically reversibel fan that changes direction every ten or fifteen minutes to clean it.

If it is not cooling it is probably not only the fan's fault. You need to make sure that the radiator is clean inside and out and that the pump is properly circulating the coolant. Also, you may want to do a coolant flush. I had a TD9 that had a sand bar in the bottom of the radiator. When I flushed it out a crawfish claw came out of the radiator. Evidently someone had refilled it with ditch water at soem point in the past!

Make sure that the thermostat is opening fully. Take it out and put it in a pot of water on the stove to check the opening temp and that it fully opens. An inexpensive infared non contact thermometer is your best tool for diagnosing this problem. You can take the temp of any part of the engine while it is running frmo a safe distance. Just be sure to look at the chart that comes with the IR thermometer so that you will know what the test area size is at any given distance. The test area is conical on those and the further you get away from what you are testing the bigger the cone is ( think of a shotgun pattern: The farther away you are from the target the bigger your shot pattern is).

http://www.harborfreight.com/non-contact-laser-thermometer-96451.html

Any sign of bubbling in the radiator when the machine is running? Also remember these are very low pressure cooling systems so don't put a high pressure cap on it.

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Thr tractor should cool either way. Suction fan in winter and blower fan in summer.

Could be that someone turned the suction fan around thinking it would cool as a blower but it will not.

Check the cup of the blades, maybe it's just on backwards.

good luck

Dennis

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Technically pushers have the ability to cool better but these basic fan designs really preclude any real gain.

I refer pushers but in the southwest there is another lesson to be learned. Pushers are nice but eat radiators quickly. Sucking gritty dusty dirt doesn't give the dirt much velocity, however grit coming off a pusher fan turns it into a sand blaster. Ed tells me Cat learned this lesson yet again in recent times.

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If you put the fan on backwards it still does whatever it did before... :lol:

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Some good info there, thanks guys. I know the previous owner rebuilt the water pump, maybe he just put the fan on the wrong way? My understanding of fans is that simply reversing rotation will make it blow but not efficiently, if it is designed to pull, then it should pull air. Judging by the amount of dust and crap on the block, I would think that it has been pulling in the past. The dust and crap wont be helping and will be removed as part of my cooling system checks.

No bubbles in the radiator, the water pump has a slight leak that I can adjust to stop it. The radiator has some minor blockage on the outside that will also be cleaned, this was my first close look at the cooling system and did not seem right, but I have learned something new today, I didn't know that dozers can work either way, but I think farmalldr is correct in saying:

"Could be that someone turned the suction fan around thinking it would cool as a blower but it will not"

I believe that if pushing air was required then a different fan would be required to work effectively. Have I got this right?

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Logger Lee, a fan will not cool if on backwards because you'll be trying to move air with the backside of the blade.

If you cup your hand and put it in a bucket of water and raise it with palm up, you'll get water. If you try it with palm down you'll get nothing.

I was only saying that some think by turning it around will make it a blower, but not so. There use to be, and maybe still is, a fan called Huber where you could reverse the blades for the season or for just blowing the trash out by reversing the air flow.

M Diesel, you are right sand blasting could be an issue in your area

Dennis

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actvd,

Looks like we posted at the same time. You are right, a different fan is required to change air flow direction or one that you can reverse the blades on.

The ones with reversable blades were very expensive as I remember.

The further out in the fan circle the more air is moved through the radiator, so keeping the outer diameter of the radiator clean is critical. Only a small amount of air moves at the center.

Having the fan shroud in place is also very important.

Good luck

Dennis

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Didn't ever say it would work, but it tries to move the air the same direction it would have (just maybe not as well)

BUT, the blades on Lil' Red (TD9) are flat, I doubt it would make much difference.

I haven't looked at the blades on the TD14a I have.

And I agree with the MD

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A D7 in Vietnam with a winter fan was so hot that a person could not operate it more than half a day. D7 tranny ran at about 375 degrees anyway so they were quite hot to begin with.

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Totally. You can't flip the blade 180 and change anything other than being less efficient due to bad curvature. Requires a 90 degree change.

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The reversible pitch fans had little springs located on the base of the shaft by the hub, you pulled outwards and rotated the blade to change direction, if the springs are missing it's fixed pitch............

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Hi all

I just checked my little td 340. The blades don't have a curve and are set to blow forward. I clean my radiator with citrus degreaser and only use a hose so I don't hurt the fins with high pressure. Check your anti freeze after a while it will not cool as well. It must be mixed right or anti freez loses cooling property.Clean and flush the radiator. You will be amazed at what comes out. Hope this helps.

Tuscarora trader

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Hi: We have another color crawler tractor with a Huber reversable fan. It has springs on the inner round mounting shank of each blade, and they must be tapped lightly inward to release them so they can be rotated. Centrifical force makes the blade fly outwards to lock them in whichever position you choose, CardaleBob

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If your cat has full guarding around the engine a push fan is nice in the summer as all the heat does not come back at you also it keeps pine neadles and leafs out of the rad.When i first got my 142 the fan was seized in the push position the only way to warm up in the winter was to stand on the blade.

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How's the timing?

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Vic, do you mean injector pump timing? If so I haven't checked it yet. Is that a likely cause of running warm? I don't know if my temp gauge is original but it has a green area that is for "operating range" mine runs at the upper end of the range but does not overheat, no boiling or spitting here, it may be that the gauge is wrong, may be a cheap and nasty chinese thing for all I know. I will get a pic and post it to ask if this is original or not, but I have a feeling that it is a cheap capillary type gauge.

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That's what I mean! The following is from a back yard mechanic, but an old one! Assuming a diesel engine acts the same as a gas engine timing-wise, if the timing is advanced too far, the pistons fire too far in advance of reaching top dead center of the cylinders. That makes the engine run hotter. You could check the setting against the manual. An old timer (50-60 years experience) told me to set the timing so that the stack runs clear until the engine starts to pull real hard. At that point the smoke should turn black. Both of my tractors do that & they purr like kittens.

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Hmm,my dozer wont blow black at all, wonder if I just need to back the timing off a little...it overheats.

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If you don't mind playing with it a little, try it. I believe my "old" source said, "don't move it much at a time. I remember that when it's close to being right, one notch will make a difference.

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Yeah,I don't mind to tinker, I'll just retard it a little at a time til' I can get some black.

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