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Trans fluid line out of radiator

Hi guys, ("99 Camry 4 cyl) I just put in a Napa radiator,$134 - Honolulu, Upper plastic cracked - are they all plastic now? My concern is the diameter of the supplied tubes for the trans cooler lines(rubber) They are one size smaller than the original so the rubber slides on easily; not the firm twist on. The package includes the screw type hose clamps which I snugged up tight enough that I couldn’t twist it. No way I would use the original Toyota squeeze clamp.I tried the old metal “elbows” but the size and depth of the flair looks different.How much pressure is in those lines? Whatta ya reckon mate? Mike

One Napa store said the pressure is high, 1400lbs I think he said…while another said it’s low pressure. I’m just concerned that I may cut the hose trying to get it tight enough…Thanks

Many radiators are plastic tanked now, although not all of them are.

The cooler line pressure will vary based on a number of things, but 1400 PSI it is not. More like 30-80, depending.

If the fittings are barbed and not smooth the rubber should stay in place with the clamps snugged. You do not want to overtighten screw clamps.

You may not want to go this extreme, but I use cutting torch hose ferrules and crimp them with the special Vise Grip pliers made for this purpose. Ferrules are cheap and the pliers are a bit pricy, but it looks professional and they won’t come loose.

There is almost no pressure on those lines. Just enough to move the fluid, 20 psi maybe. Since the line is open, no real pressure builds up.

Caddyman has the answer. The fluid leaving the transmission is coming from the torque converter at very low pressure. It goes into one line; passes through the cooler/heat exchanger; goes back to the transmission in the other line; and is dumped into the sump. Therefore, the only pressure that can be developed is the flow resistance of the circuit.

I suggest idling the engine; looking for leaks; and tightening the clamps until there are none. Hope that helps.

There can’t be much pressure on those lines. Many OEM manufacturers use standard hose and clamps. I know of no hose that handle 1400lbs of pressure…let alone 140lbs of pressure.

Thanks guys, No leaks so far. Amazing how light the radiators are now...  Mike

No way I would use the original Toyota squeeze clamp.

I know that those squeeze clamps look inadequate … and sometimes they are. But they have one characteristic that hose clamps don’t. They stay about as tight if the hose rubber compresses over time. If you use hose clamps, orient them so they are easy to tighten a bit more if they start to leak after six months or a year. And check them for leaks every now and then. I’ve had cars where I used screw type hose clamps to repair the cooling system and had to tighten them a bit every year.

It’s not a bad idea to pop the hood every couple of weeks and check the fluid levels – especially on a ten year old car. If you find the transmission fluid level creeping down, check those hoses.

You have little to worry about. Toyota transmissions operate on very low pressure, maybe 20 psi at the most. One thing you could do as cheap insurance is to get a couple more hose clamps the same size and use two of them on each fitting, orienting them so the screw is on the opposite side, facing the same direction. This will help to ensure there will not be any leaks, giving you additional peace of mind.