Looks like there is a partial TSB for this now. March 2026 but just a limited MY.

 

Yeah, the parts desk at my dealership checked my vin on my 2020 and said it wasn't included.

 

I wonder if this is a cost-saving measure or there was actually a different o-ring used in the 23+ years.

Needless to say, those of us on the 22s and earlier are feeling a bit left out in the cold.

 

Received the same letter in the mail this week. Luckily haven't had any coolant issues on my 24MY yet, but not taking any chances. Scheduled my service for tomorrow.

 

I didn't receive this letter. Just relaying what someone posted on FB.

I don't see how this doesn't affect all P400 engines out there regardless of year.

Mine is a MY22. Wouldn't be covered under this. That's $26 I'll never see again. It'll be a lean Christmas this year.

My new o-rings looked to be identical to old. There is no change in part numbers. Yellow o-rings.

Interestingly the o-rings on the replacement coolant pipes I ordered and subsequently returned unopened, have a red color o-ring.

 

The o-rings I bought at the dealership were red.

 

I will ask my service advisor tomorrow as to why previous model years were not included in this TSB.

The o-ring color change to red is, to me, indicative of a part number revision. Likely the tier 2 or tier 3 o-ring supplier made the change (directed by JLR) and the revision is noted on the engineering technical drawing. Because the o-ring is part of an assembly the JLR part number would remain the same but it *should* have a superseded suffix (ie. PN12345678AA --> PN12345678AB)

 

It definitely affected 2020 - 2023 too. So, all of them w/ P400. Mine were replaced under warranty when the truck was a year or two old, I think around 2022. In fact there was an old TSB about it they referenced on my invoice (which has been updated pretty much annually - including last year). See attached.

 

Interesting, the old TSB performs a coolant leak test then replaces o-rings if necessary. The new program on 23-24MY goes ahead and replaces the hoses and o-rings seemingly without a leak test.

 

Mine were also from a dealer (JLR Portland aka landleaping.com)

Red never leaks. Everyone knows that. I guess I'll add new o-rings to the schedule every 70,000 miles.