Found leak in the return line from the transmission cooler rad going back into the automatic transmission.

The O-Ring is blue in colour, not seen that before.

When i cleaned it and put it back on it still moves easily compared to the other pipe (engine running).

Has anyone replaced the O-Ring in this pipe? what sizes, type ?

You're going to need to change the pipe I'm afraid

Yeah, might have to. Would the small leak effect the transmission shifting?

Also, what is this pipe on the top of the transmission used for?  air valve?

 

 

Found this Aussie lad very helpful for getting the connector off.

Automatic Transmission Cooler Line Quick Connect Removal when limited room no special tools needed

YepThatsIt

https://youtu.be/EY4pa8bR0k0?feature=shared

If any evidence of leaks, check level (should be done as per service or more often when older?) Doubt if tiny leak would cause problems unless it reduced level?

The fittings do look very similar (why so many different designs with confusing ways of releasing?), plus he mentions changing the O rings BUT getting the correct ones will be a matter of material and sizing?

The other photo... there has to be a way to avoid pressure build up (and resulting oil leaks) when the air inside the gearbox gets hot so I agree with you?

On 4/11/2025 at 9:18 AM, DaveT70 said:

You're going to need to change the pipe I'm afraid

Think I'll get my spanners out and get a closer look at it... might try replacing the O-Ring.

If I do I'll upload photos and O-Ring sizes i find.

Would I need high temp FKM type O-Rings or would standard nitride rubber rings be ok?

On 4/11/2025 at 11:14 PM, ride_comfort_is_my_object said:

Also, what is this pipe on the top of the transmission used for?  air valve?

 

This is a breather hose

On 4/10/2025 at 10:48 PM, ride_comfort_is_my_object said:

Found leak in the return line from the transmission cooler rad going back into the automatic transmission.

The O-Ring is blue in colour, not seen that before.

When i cleaned it and put it back on it still moves easily compared to the other pipe (engine running).

Has anyone replaced the O-Ring in this pipe? what sizes, type ?

 

 

Is it like this ?

Heater cooler line O-Ring feels like it's made from silicone and not NBR Nitride rubber or high temp FKM (fluorine rubber) material.

I'm guessing from my measurements that the O-Ring I'll need to replace are something near to OD 13mm x CS 2.1mm.

Big tip.... Couldn't get the connector off for love nor money.  Then remembered something the Aussie chap said, oil it up first as the plastic clip inside is most likely stuck not freely moving. Best way to getting these connectors off is to use penetrating oil (wd40) on it first, then work the oil inside by moving the connector around. Then push the connector fully forward into its connection, then lightly press the side clips in and pull the whole connector backwards.

3 minutes ago, unofix said:

Is it like this ?

Looks like it,  you have any specs on it? or web link?

29 minutes ago, ride_comfort_is_my_object said:

you have any specs on it? or web link?

Hi, sorry no Ford spec on it. Seems to be used on multiple Ford models and confusingly it is listed on both fuel pipe couplings and air con fittings.

Just google either the finis code 1718422 or the Ford engineering part number AB3919214BA

In the end i ordered these from Amazon, Fluorine Rubber O-Rings 13mm OD 9mm ID 2mm Width, Metric FKM Sealing Gasket, Pack of 20 for £7

https://www.amazon.co.uk/dp/B08HHCYQR5?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

Perfect fit, go into the pipe popping into location and give snug fit when pushed on. It's fitting.