automatic transmission cooling lines

[bart383]

I am replacing the oil lines on my 727 gearbox to radiator and have a question on the cooling connections.
I have been very optimistic with removing them, but did not pay too much attention to which one is mounted where on the radiator.
The one that is connected on the back side of the transmission (from cooler), should that be connected to the left hand side of the radiator or right hand side? (sitting in the driver seat). Or is either connection fine?
Is it OK if I replace the oil lines with hoses instead of metal lines?

Thanks

Bart

[dodgeboykim]

I am replacing the oil lines on my 727 gearbox to radiator and have a question on the cooling connections.
I have been very optimistic with removing them, but did not pay too much attention to which one is mounted where on the radiator.
The one that is connected on the back side of the transmission (from cooler), should that be connected to the left hand side of the radiator or right hand side? (sitting in the driver seat). Or is either connection fine?
Is it OK if I replace the oil lines with hoses instead of metal lines?

Thanks

Bart

You could replace your lines with hoses, But you would have to use hydraulic hose or hose rated for ATF. Steel lines are simple and reliable. And probably a lot cheaper.

[bart383]

thanks.

Should there be a part of the lines made out of rubber for flexibility, or can the whole line be made out of metal?

What about the connections on the radiator? Does it make a difference which one is mounted where?

[dodgeboykim]

thanks.

Should there be a part of the lines made out of rubber for flexibility, or can the whole line be made out of metal?

What about the connections on the radiator? Does it make a difference which one is mounted where?

Their is a route that should be followed to have to hot in and cool out to rad so it works as best as possible. All Mopars with 727 or 904 have their respective locations for lines.
FSR should shed some light on it or another forum member. Unfortunately I don't remember or have anything at this time to look at .

[my5thmopar]

Your factory lines will only go one way due to the bends. The longer one is rear of trans to RH on radiator. All your doing is circulating the fluid through the radiator and the air is cooling the trans fluid. In really doesn't matter. I believe the factory always has the front of trans (pump side) to radiator hot side (water in). I don't like using hose even though the pressure is around 45 psi. I think you're asking for it.

[712edf]

Stick with metal lines. Rubber retains heat, the metal dissipates heat better.
Some use a short (6") section of hose on each line near where they connect to the radiator, just for the aforementioned flexibility. But more hose means more connections & potentials for leaks.

Bucky

[coelcanth]

On my 69 d100 with 727, the line from the rear of the trans passes under the timing cover and over to the passenger side of the radiator. It's also the upper most line in the double decker sheet metal brackets that bolts to the oil pan.
The line ends in a flare fitting that goes to a short rubber hydraulic hose with a crimped on 1/8" npt male fitting to thread into the rad

Btw: I snapped one of those fittings off in the trans cooler and ripped the hose, but I was able to drill it out and thread in a brass hose barb and reuse the old rubber line with a hose clamp.
It seems to be holding up fine for now

[Jake66]

thanks.

Should there be a part of the lines made out of rubber for flexibility, or can the whole line be made out of metal?

What about the connections on the radiator? Does it make a difference which one is mounted where?

as far as flex goes, you could put a few coils in the line ( if your using steel lines ) almost the same as you would do with brake lines. that would allow for some flex. i personally went with hydraulic hoses with a steel braided exterior and high pressure swivel fittings.

for ease of flow out of the cooler id put your pressure line on the top connection and low pressure return line on the bottom connection.

[bart383]

thanks all!
I will go for the all metal lines.