Tesla Model S 85 emergency coolant leak: when the real fault is a previous battery refit
A Model S 85 came in with coolant pouring from the battery's rapid mate connector. The leak was only the symptom. The real problem was how the battery pack had been refitted after a repair elsewhere.
personBy Gabor, MegaEV calendar_today 2 min read
This Tesla Model S came in with coolant pouring from the battery coolant rapid mate connector, the fitting that joins the battery pack's cooling circuit to the rest of the car.
The real cause: a previous battery refit
The battery pack had been removed and repaired elsewhere before. When it was refitted, the battery pack and the front subframe had been left badly misaligned, and the coolant connector had been damaged.
That was not all. Two of the main battery-to-subframe bolts were missing completely, along with some of the longer battery pack bolts.
The repair
- removed the battery pack
- replaced the damaged rapid mate connector
- realigned the front subframe
- carefully refitted the pack in the correct position
- refitted all the missing bolts, now that everything lined up properly
Fortunately, we had the correct hardware available from one of our parts cars, so there was no delay waiting for parts.
After refilling the coolant system, we ran the required air purge routines, to make sure no air was trapped and the system was working correctly.
A second problem found while it was apart
While the car was apart, we also carried out a quick health check, and checked the large drive unit (LDU) speed sensor. On rear-wheel-drive and Performance Model S cars, these sensors are well known for letting coolant in, unless the coolant delete modification has been done.
Unfortunately, this one was already wet. So although the coolant leak is now fixed, the car needs further preventative work before the LDU's isolation fails or coolant damages the LDU motor. Our drive unit maintenance and repairs service covers the coolant delete modification, and you can see one in our complicated Model S coolant delete entry.
Why previous repairs matter
This is exactly why previous repairs on a Tesla matter. The leaking connector was only the symptom. The real problem was the way the battery pack had been refitted.
If your Tesla has had major work done elsewhere and something does not feel right, or you are unsure about a previous repair, send us a message. A health check can show whether the work was done properly.
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