inittab

I just got a new radiator for radiators.com. The thing looks pretty darn good 'cept there's something strange about it. Out of the bottom housing there are two small "tubes" that stick out of it. At the end of the tubes are rubber caps that are easily pulled off. What the heck are these tubes for? TIA

Directfreak

iTrader: (2)

For the Automatic equipped cars.

MyRxBad

I thought the same thing when I got my new rad, but the tubes are the auto tranny cooler line, they run inside the rad. Just block 'em off, or do what I did and run a silicon tube from one end to the other.

inittab

huh, interesting. I specifically ordered a rad for a manual transmission too.

MIKE-P-28

iTrader: (1)

All aftermarket ones are like that, mine is... Just hook up as normal and ignore them ...

inittab

Maybe I'll run it to a radiator shop to see if they can cut 'em back and braze 'em up. I think the tubes might get in the way of my elec. fan.

jr69187

yup wack em off and the fan will fit i had to do the same thing.

jr

peejay

Why bother brazing them up? Just snip them off with a side-cutters. They won't leak coolant. If it corrodes internally to the point where it leaks, the rest of the radiator will be in pretty bad shape by that time too, so it's time for replacement ANYWAY.

inittab

so if I cut them off it won't leak? Where do the tubes lead?

peejay

They go to the transmission cooler. The transmission cooler, of course, is sealed from the coolant.

If you have a manual transmission, it's not needed. Almost all aftermarket radiators automatically (tee hee) come with the cooler, because it's cheaper for them to make and stock only one radiator for automatic and manual cars. It's cheaper for Mazda to make separate radiators for manual and automatic because they know approximately how many manuals and how many automatics they will need, so they can save money by not putting trans coolers in the manual cars' radiators.

Directfreak

iTrader: (2)

Ok, now you guys have successfully confused me.
Are you saying that there is no flow through there?

So all you have to do is cut them off?
Not even cap them off?

It won't leak all out?

Pele

iTrader: (28)

The tranny cooler is like a little tiny radiator, Inside the big radiator... They rarely fail. Usually due to the transmission fluid pressure being too high. Since you have a manual, this is of no concern to you.

They work by circulating the hot ATF (Yeah... It get's HOT... I've gotten 2nd degree burns from outgoing tranny fluid after I warmed up a tranny at the shop preparing for flushing it...) through the cool coolant (At the bottom.)

If they mixed, you'd have tranny fluid in your coolant in an auto equipped car...

If you really wanna get creative, you can rig up a pump to circulate your rear end or tranny gear oil through it... That's ony for hardcore road racing though...

851stgen12a

God that would be cool. thats a long way to run the rear diff fluid

peejay

You'd have to really work to get manual trans or diff oil up hot enough that the engine coolant could cool it down

Automatic trannies get VERY hot... there's quite a bit of heat loss in the torque converter due to fluid friction when it's "slipping". And the fluid gets hot just by being pumped by the pump in the tranny too..

inittab

Okay.... so the little tubes coming out of my new radiator are so the ATF can flow thru a sealed section of the radiator. Do I have the right? ... Good! ... Another use for a dremel peejay..... you da man!!!! Thanks!!!!

RotorMotorDriver

iTrader: (1)

Could you use it as an oil cooler? Braze some fittings on there, and then make some custom lines...Would that work?

~T.J.

Keaponlaffen

Then you'd just have a second air/water oil cooler, like the stock 81-85 one...

Or should I say Oil heater?

Jeff

Project84

The ATF that runs through a radiator is cooled the same way the anit-freeze is; the ram air flowing through the front of the car as the vehicle moves forward. Its like the oil cooler for the 2nd Gen car,on the 2nd Gen's are not built into the radiator. It would be very benefical to run engine oil through the ATF section of the after market radiator, considering how poorly the original 1st gen setup cools oil. (IMO)

peejay

Actually, the oil cooler IS like the oil "cooler" in '83-85 12As. It's a water/oil cooler. The coolant keeps the trans fluid temp regulated - when the fluid is cold, the coolant warms it up, and when the fluid is hot, the coolant cools it down.

Project84

But what has a bigger impact on ATF temp? Coolant temp,or ram air?

RotorMotorDriver

iTrader: (1)

So ummm...Could...No, SHOULD you do it? Or would a real air/oil cooler be better? Cause to go from the water oil cooler, youll be at the junk yard anyway to get the filter thing and stuff anyway...

~T.J.

Project84

Oh yeah, the filter is a good point. I forgot that the 1st Gens have the oil cooler right under the filter. That is one improvement on the 2nd Gens (GSL-SE too?) that the pump pumps oil directly out to the oil cooler, then to the back of the motor where the filter is like in this pic.

rx-7girl

okay with my sexy auto tranny.......and my sexy radiator that uses the two little lines hehe anywho.......why doesnt the manual tranny fluid get as hot as atf?

and in first gens is the oil pumped to the oil filter then the oil cooler? is that why the filter is on top of the engine? i kinda figured that from projects post.... but just wondering if its right and if it makes more sense to run the oil cooler first why did mazda do that inthe first place?

Pele

iTrader: (28)

The Auto tranny fluid gets hot due to the friction of being pumped around by the torque converter.

Think of the torque converter as a set of fan blades. One set of blades is mounted directly to the engine flywheel. The other set of blades is mounted to the tranny input shaft.

When you're stopped, the engine blades spni, but the transmission blades do not. This pumps the fluid around. When you let off the brake, the fluid thats swirling around pushes the blades on the tranny and moves the car... When you get on the gas, the pressure of teh fluid builds up and opens some valves and **** to upshift or downshift... Or something like that...

On the idea of using it as an oil cooler, In addition to the fact that it's not efficient enough, doesn't engine oil get to higher pressures than ATF? Aside from that, some Caddilacs use similar, but seperate coolers in opposite end tanks (Side mounted end tanks on their radiators.) One for the ATF, one for the Oil.

I have to go back home and look at my factory manual to see the oil pumping path for the 12A and 13B...

Project84

lol, so technical

Why would it not be efficient enough for a 12A, but they have air/oil coolers for 13B's? Or do you mean that the auto tranny portion of the radiator isn't efficient enough?

The stock oil pressure relief valves bypass oil somewhere between 60-70 psi. My haynes book doesn't show how much pressure is inside the tranny, but I would imagine that at least the torque converter would have more pressure inside than 70psi.