What would happen if you mixed up the trans cooling lines?

What would happen if you mixed up the trans cooling lines by attaching the trans out line to cooling out and vice versa. Then, started the engine and let it run?

so nothing would get damaged or the pump wouldn't work?

You put more strain on the transmission pump.
the stock system uses gravity to help the coolant flow, it leaves the transmission, and goes to the top of the radiator, flows through the radiator and out the bottom, then from there it goes back to the top of the tranny cooler, out the bottom and back to the trans.

If you had it reversed, the pump would be trying topush fluid through the bottom of the cooler, up through the cooler, out the top into the bottom of the rad, and up through the rad to the top.

More weight to push.

Check it and make sure its not backwards! hahaha

410 that makes no sense - gravity?

the tubes have to go up to get to the top of the radiator cooler- what the hell difference does it make if the fluid goes up through the cooler or up through the tube????????? . The trans system is pressurized, gravity is not a big factor when choosing top or bottom inlet. More likely has to do with coolant temps in the radiator - hot coolant enters at the top and cooler coolant exits at the bottom. It doesnt add any stress to to the pump if the cooler lines are top or bottom.



If you are using logic like that then the Fluid would flow much much better with the inlet at the bottom of the tank- the cooler is much larger diameter than the tube so much much less restriction and pressure loss so it would be easier to push the fluid up through the cooler


Like jeff said it isnt going to make a difference to the pump. Cooling efficiency may be hurt . As afar as I know there is now backflow valve in the cooler.

What ever the case - the cooler on backwards isnt the reason you get no fluid through the lines. ( how many threads do you have going on this?? )
You may want to flush the lines and or cooler- if the lines are backward you could have dislodged some debris and it is working like a check valve. When you pulled the engine did you disconnect the trans lines?
Did you check the torque converter/ flex plate mating surface? Did you check the pressure in the trans? If so then I would check the trans for pump engagment.

Good Luck

I am sorry but you are not thinking it all the way through.

In reverse the pump will be pushing the fluid uphill. meaning it is easier to fill the radiator from the top, instead of trying to force fluid up from the bottom, because the weight of the fluid in the radiator will be working against you.

You see my point? The radiator full of ATF , the ATF will want to flow out the bottom of the radiator, so this helps to feed the cooler. You dont want to try and fill the cooler from the bottom, because the wieght of the fluid in the cooler will push against you.
Ford plumbed the lines in the stock order for a reason.

The other way around means the pump will be responsible for pushing fluid first through the cooler, from the bottom. Pushing fluid up through the cooler and out the top. Then the fluid would be routed to the bottom of the radiator, and the radiator cooler would again get filled from the bottom and the fluid would come out the top. then back to the transmission. the weight of the fluid in both coolers is working against the pump which os trying to fill them up!

Working against gravity.

This is the reason why coolant is returned to the top of the radiator, not to the bottom. Sure the waterpump (in our case tranny pump) has adequate power to fill the radiator backwards, but why ask it to do that when you can use gravity to your advantage?

Hook a hose up to the bottom of a bucket (cut a hole).
Fill the bucket.
Which way does the water flow? out the hose right? because the weight of the water in the bucket.
Now is it easier to fill the bucket with water from the hose? or from the top of the bucket?

I am not saying its much, I mean we are talking 2 quarts of ATF in the coolers and lines, correct? So its not going to kill the pump, but it certainly does not help.

The trans cooler is just a little larger tube than the feed lines with some external fins thats contained in the radiator. The radiator doesnt fill with ATF. The cooler is a sealed tube within the radiator- I dont think Im reading your words correctly.

If theres a qt of fluid in the cooler it weighs maybe 2 - 3 lbs - the pump works between 100 and 300PSI I may be off base, but I dont think the 2 lbs of fluid are really going to hold back the 100 psi pump.

Look at the stock aux cooler- the inlet and outlet are on the bottom- wouldnt they need to be on the top and bottom?

It doenst matter where the fluid enters. It wont effect the pump.

In a closed loop system

gravity doesn't make any ditterence. For example. You could put a hose in your gas tank, run it over the top of your house, and siphon it into a can on the ground next to the car.

I think I have the only difference. More dirt. Stuff that has clung to the walls of the cooler will be disturbed by the different direction of fluid flow and go into circulation.

Da bucket. It is faster to fill the bucket from the bottom. A pump has to overcome more height if the hose has to overcome more height filling it from the top. If you take the hose over the top of the bucket and drop it to the inside bottom of the bucket, then it is the same.

Okay Steve I understand what you are saying.

Yes the pump is obviously capable of pushing the fluid through the system in either direction.

I know all about the stock system and what it consists of, Believe me I built mine when I converted my truck from a 5 speed to an auto. On my truck I am using rubber tranny cooler lines form the tranny all the way to the radiator. I am also running a class a motorhome tranny cooler. My cooling system holds almost 2 quarts of ATF as best I can tell (By flushing it). When I flush the coolers (when I do a fluid change) I use my mouth and lungs to get the fluid out of the coolers.
Disconnect both lines from the tranny. Which line do you think I blow in? The one that goes to the bottom of the coolers? or the one that goes to the top of the rad?
thats righ the one that goes to the top of the rad, because otherwise I would be pushing all the weight of the fluid upstream, instead of letting gravity help me push it down and out....




You are right when you say the stock cooler is only slightly larger than the tranny cooler lines, as is the cooler built into the stock radiator.

However to say that it will not effect the pump is not correct, meaning that although it may be a small difference, there is a difference. I personally dont want to put any added strain on the pump regardless of how small, if it can be avoided, avoid it!

Think about it, no matter what the pump is responsible for pushing fluid out of the trans, through the cooler lines, through both stock coolers, and back to the trans.

The reason Ford has it entering the top of the radiator mounted cooler is because it will help the coolant flow through the system. In reverse it would not get any help, it would only make it harder to push the fluid through.......

Stock = enters top of highest cooler (rad)

Backwards = enters stock cooler, then out and back into rad cooler from bottom up.

Not going to help.

Can you run it that way? Sure! Is it going to blow up your tranny? Probably not, as we agree it is only a little fluid being pushed through some small lines. But is it going to help the cause? Nope its going to make it harder for the pump to push the fluid is all......

Opera House, would you want to have your waterpump fill your radiator from the bottom up, and take the coolant back to the engine from the top?

That is a closed loop system too!
I serisouly doubt you would want to run it that way!!!
the waterpump would have to work harder to fill the radiator from the bottom that it does from the top.

Do you agree?

Originally posted by JDraper
Actually, the primary reason for flowing top to bottom is because heat rises. This way, the fluid is flowing the opposite direction of heat flow, providing slightly better cooling.

Click to expand...

Originally posted by SteveVB
The trans system is pressurized, gravity s not a big factor when choosing top or bottom inlet. More likely has to do with coolant temps in the radiator - hot coolant enters at the top and cooler coolant exits at the bottom. It doesnt add any stress to to the pump if the cooler lines are top or bottom.

Click to expand...

Same reasons the coolant fronm the engine enters the rad at the top and exits at the bottom on most all vehicles

Gee, mine goes side to side

The reason the hot goes in the top has nothing to do with the pump.

OKay so what you guys are saying makes perfect sense, I wasn't thinking of the closed loop operation , because when I drain the fluid from my coolers I disconnect the lines, making it a open loop system.


So the pump does not see additional pressure because the fluid is pushing on both sides of the pump impeller.

However we all agree that the fluid should enter the top of the radiator first, for one reason or another.
It would work the other way around because it is a closed loop system but you wont find me changing mine around!

Steve, after mating the trans back up at first I did mix up the cooling lines, and yes I did disconnect the trans lines when I pulled the engine. Then I started it up and let it run for a minute, and then started shifting through some gears to try to get the trans fluid pumping through, but no luck and do gears are engaging. I have not checked the pressure in the trans, actually do not know how? After switching the cooling lines, nothing has changed and I assume the pump is not working. Should I check the pressure next. Also, as far as I know the TC and flex plate mated fine. I appreciate all you help and glad you guys got some conversation out of the cooling lines. Thanks again.

Grisc,

you can take the pressure reading off of the port on the driverside of the trans right above the linkage. You can rent, buy, or borrow a gauge. I got mine a while ago A think it was 40 bucks or so.

I would make sure the trans is full of fluid. Did you change the trans filter? Check the o-rings and or pick up tube for correct pplication.

If youve shifted it through the gears and the fluid level is ok, and nothing else changed when you removed the engine. Ill stick with my idea that the torque converter isnt engaging the pump. Means removing the trans or engine to reseat the converter.

Sorry

410 yes I do agree that for best eff. the cooler lines should enter at the top.

Good discussion hope everyone learned something - I did, and one of the great things about this site.

that is the purpose of this site! Also I dont mind addmitting when I am wrong, or having a brain fart or whatever........

I had to think about it for a few minutes thats for sure!
I just remember recently I did a fluid exchange in my tranny and I wanted to evacuate the fluid from my cooling system.

The best way I could think to do this was to disconnect both lines at the tranny (remember I have rubber lines). I let the fluid drain as much as it would by dripping out, then I put my mouth on the "outlet" hose and pushed air through the system until air came out the other hose.
I realized real quick which line was which becase blowing into the "inlet" hose (back to the tranny) was not gonna happen, but it was really easy to get the fluid through the other way.
However I forgot, in a closed loop system both hoses would be in my mouth so it wouldnt matter which one I blew into, the fluid would come back to me through the other one!!

hahaha! Thats what I get for thinking......

steve, alright I know someone who has a gauge I can use, so what reading am I looking for? Also, I did not change the trans filter. I just wish I didn't have to unmate that trans again. But, if that is the only way I guess I might have to.