trans cooler install 92K1500

Ok,

Installed the aux trans cooler that I posted the diagrams too.... some time ago. Have not installed the hoses yet.

I want to install the aux trans cooler in series with the OEM trans cooler that's part of the radiator. Instructions show and other references say that on a 7004R the top trans cooler line at the radiator is the return line.

So I crank truck up and let it run a while. I touch both the top trans cooler line and the bottom trans cooler line (at the radiator)to see which one is hotter. My assumption is that the return cooler line would be cooler, since the fluid has been cooled? Truck just idled for a while...

ON my truck the top cooler hose at the radiator is hotter than the bottom line, which does not seem right to me? I'm wondering if the cooling lines were swapped at the trans when trans last worked on?

Can anyone tell me which fitting on the trans corresponds with the top or lower fitting on the trans cooler...at the radiator. 1992 K1500

7004R trans....350 engine.

I know I can disconnect the hard line at the radiator to see which way the fluid is flowing but would prefer not to do that..

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert
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Truck just idled

How can a simple radiator with no fan cool anything with the truck sitting still idling? The cooling action comes from cool air moving across the cooler as the truck moves. Your experiment was faulty logic.

Reply to
Advocate

you mean no outside fan used I'm guessing?

Radiator fan on truck pulls air across the radiator when engine is running no matter if truck is moving or not. Yes air flow is reduced but its not true to say that there is no air flow.

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert

why does it matter if the fluid goes through the stock cooler first or the aux. cooler its still two coolers in series...run to the line that is the most convenient.....most aux. coolers are non-directional

Reply to
taz

That's the way the directions are written so my assumption is that its the best setup, or the most efficient manner in which to cool.

The GM directions speak to this as well as those from other manufactures, so that's what I want to do.

I don't want to cool the fluid before it goes into the radiator, but do want to cool the fluid after it comes out of the radiator and before it goes back to the transmission.

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert

You ALWAYS route it through the tank cooler first, then the aux coole. THe reason that the poster was confussed is because GM recirculated coolant through tank that stock cooler is in as engine warms up to it will help warm up the transmission too (which it is designed to do) because it best range it around 180 to 200. Then top ine is the tranny return line and alway has been on GM trucks (if you doubt it break line loose and start truck and be ready for th flow coming out of tank) That is where you take oil/fluid then route it through aux cooler and then back to tranny.

----------------- The SnoMan

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Reply to
SnoMan

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a link

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~:~ mm ~:~

Reply to
Marsh Monster

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Elbert,

Top line on tranny= return line

Lower line on radiator= return line

a link for fun..........

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~:~ marsh ~:~

Reply to
Marsh Monster

I popped a temp gauge on my trans.

Perhaps my aftermarket cooler is too big but the only way I could get the transmission near operating temperature was to run it through the aftermarket cooler first then through the radiator to heat the fluid some. Still runs cool (125 or so) unless I'm towing then she gets a little warmer.

-- Dave

Reply to
Slap

thanks everyone for the advice...

got the cooler installed, grill back in and I had some hydraulic style hoses made up that will work without having to cut any of the hard line.

have one minor leak to address at the radiator and I'll done.

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert

Just found and read through this. Lots of bad information. Glad you figured it out. What GM recommends is you send the fluid through the aux cooler first, then through the radiator cooler. Snoman gave the correct reason, but the wrong way to do it. If you want to verify this, look in the Chevy truck shop manual. Or, the motor home shop manual. It gives too much info but is very interesting. Even has charts to explain transmission life with normal, colder than normal and hot fluid. As the fluid gets hotter, transmission life goes down quick. The motor home manual says, but I find hard to believe, that on a long uphill pull, the in-radiator transmission cooler can cause the engine coolant to overheat. That's one of the reasons they say to cool the fluid before dumping it the in-radiator cooler. Snoman explained the other.

Al

Reply to
Big Al

In what regard??? If you want to get technical, the reason it flows from bottom to top of tank cooler is because the coolant is at its coolest (in relation to a hot tank cooler) when it first enters the tank and starts to flow down over internal heat exchange and be heated some so you want the hottest fluid at the bottom end were coolant will be hottest in its pass over it and as the oil flows upward it contacts cooler coolant as it cools too mantaining maximum heat transfer efficency.

----------------- The SnoMan

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Reply to
SnoMan

I don't think what you are saying is correct in relation to the light truck line 1500 and 2500 trucks. if you will reload the headers in this group you'll see the directions I posted a month or so ago. Scanned copy right from the GM part (trans cooler) included instructions that pertain to C&K trucks.

Instructions clearly show that the cooler is installed in series with the radiator, with the radiatior trans cooler being first and the auxillary trans cooler being 2nd.

I'm think if the transmission gets as hot as you say you've got some serious problems. On my truck I'm not concerned with the transmission fluid over-heating the radiator....I am concerned about the fluid getting a littl hot in 4wheel drive and off-road or driving in the moutains.

Look at the instructions I posted to see what we have been discussing. I think if you look at some of the other web sites like TCI , B&M and others you'll see similar directions.

Seems to me that if you cool the fluid prior to the radiator you're just giving it time to "re-heat" when it passes through the radiator and then back to the transmission. Settng the cooler like I've done allows the air-to-air cooler to cool the fluid without the influence of the radiator before it goes back into the transmission.

I do have a shop manual for this truck , which I admit I've not looked at in reference to this subject, I don't recall the factory C*K truck manual talking about auxillary trans coolers? I'll look over the shop manual to see.

On another tangent...I think you'll see the light trucks that come with the trailer package and maybe the Z-71 packege have an auxillary cooler and its setup in series and I'm fairly sure (since I don't own one) that the coolers are setup as I described doing with my truck, radiaort first, aux cooler 2nd.

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert

You could be 100% correct. What I originally read was in a medium duty truck manual. It did give the reason Snoman mentioned about the radiator heating the trans fluid to help get the transmission up to temperature. I have a 99 light duty service manual here, but that's the only LD manual I have. I'll try to remember to look and see if there is anything in it. If a trans cooler was a factory option it should be in there.

Al

Reply to
Big Al

i really didn't think that it mattered which cooler went first based on the fact that i never put two in series anyway...all the aux coolers i install stand alone and are put in after trans re-builds...that is the strict orders of the trans shop...but could they be setting themselves up for failures by not going through the rad to bring up the temp....especially in the cold canadian winters...

Reply to
redeye-racing

i really didn't think that it mattered which cooler went first based on the fact that i never put two in series anyway...all the aux coolers i install stand alone and are put in after trans re-builds...that is the strict orders of the trans shop...but could they be setting themselves up for failures by not going through the rad to bring up the temp....especially in the cold canadian winters...

Reply to
redeye-racing

transmission

Found a factory 91 C K shop manual. No mention of any aux cooler. Did have some info on the in-radiator engine oil cooler:) The thing I originally read was a packet of amendments. Had stuff about installing a trailer hitch, trailer brakes, how to run the wires for two way radios and so on. The chapter I tried to quote was in the towing stuff. When I get some time I'll see if I can find it again.

Al

Reply to
Big Al

There are some miss conception here and it is even more surprizing to see it at a tranny shop. There is nothing to be gained by running a tranny too cool. It need to be able to get up to 180 or so so that the fluid flows properly and it keeps condensation evaporated out too. The biggest possible is very rarely actually needed. On my 89 4x4 burb I have installed a heater water shut off valve so I can shut heat fully in summer for max AC as GM does not shut heater core off in summer. Shutting it off gets cooler air and boost cooling a bit too but the reason I mention it is that if it is shut off in cooler weather it takes noticably longer for tranny to warm up as no coolant is flowing over tank cooler until Tstat opens. (it has a small aux cooler too.)

----------------- The SnoMan

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Reply to
SnoMan

their reasons for the aux cooler has actually nothing to do with heating or cooling improvements at all...its the possibility of contaminants in the factory cooler...hook up the aux only or no warranty...NO exceptions... installing coolers to the best cooling ability is not that important here ( NW Ontario)...80% of tranny failures come in my shop in the winter, 10 % off road recoveries and 10 % damage or catastrophic failure. the only over heated ones are the offroad recoveries, and coolers wouldn't have helped their foot's in the oil pan and they are not moving.

Reply to
redeye-racing

They are missinformed an seem to think that they know more than manufacture of tranny. If there is a "question" of contaminants. it is easily flushed and a poor excuse and this also reduces A/C efficency some as it place extra hot air on condensor so refrigerant does not cool as much. You have yo look at the bigger picture of overall cooling and not just these hang on bandaid solutions.

----------------- The SnoMan

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Reply to
SnoMan

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