'08 5.4 transmission fluid leak

chetubi · 10-28-2015, 04:04 PM

I could need some advice here in germany.

My 2008 e350 eb 5.4 SMB has a minor leak of transmission oil.

As i see it has No seperate oil cooler!? It is in the radiator.

We has a leak (water) in this radiator on our way through the US in SLC. The Ford dealership there replaced it with an non Ford Aftermarket radiator.

Now in Germany i see one hose (?) on the drivers side is leaking. You Can See it in the pictures below. Not much. Just with running engine. Perhaps already since the time of replacement?

Tightening the screw did not help.

What Would You do? Here they suggested a seperate oil cooler.
But is it wise to stop the flow through the normal radiator which brings the oil quickly to working temperature?

Of Even a new Ford radiator? Of any quick and durable fix?

Thx in advance!

Philipp

Pntyrmvr · 10-28-2015, 05:17 PM

Hi,

I wonder if the hose clamp is not sealing the hose to the fitting. Try another hose clamp.

A cheap way of eliminating that clamp as the problem.

Regards,

Gavin

carringb · 10-28-2015, 09:55 PM

While that is a very common leak point on new aftermarket radiators, its often just the hoses. Rubber hoses on hot transmission lines take a set, and won't clamp back down onto a new nipple. On my van, I was able to trim the lines back once. The 2nd replacement radiator required splicing in about a foot of new hoses to attach to the radiator. I doubt the clamps themselves are weak. Those are actually a better clamp than worm drive clamps... But they only work a good hose. (worm drive clamps can squeeze tighter though, they can work if the hose isn't too hardened).

As for bypassing the in-tank cooler... I don't recommend it. It actually doesn't really provide any warming, as the coolant in the bottom of the radiator should already by close to ambient air temp, especially during warmup. The in-radiator cooler is very efficient, and can transfer more heat than most air-to-oil options.

A little relevant history... In the early 2000's Ford saved a few bucks and built a lot of pickups without the radiator oil cooler, having only the air-to-oil cooler. This of course resulted in many pre-mature failures. If the repair shop did not opt to replace the radiator with a built-in cooler, the spec was to install a 40,000 BTU air-to-oil cooler. It's giant!

JWA · 10-29-2015, 03:54 AM

That leak could also be the fittings going into the radiator tank itself---seems to be a bit of fluid closer to the radiator too.

Were this my leak I'd first try GENTLY tightening the larger fittings. If the leak persists I'd remove the hose and those larger fittings, clean the female threaded portion and use either Teflon tape or a liquid sealant like LocTite's PST---both those approaches would pretty much seal any leak or loose fittings.

The hose barb fittings could benefit from a bit of Teflon tape but should tighten in enough to seal. Using a back up wrench on the larger fitting while tightening the hose barb would be highly advised.