Model S & X Air Suspension Sagging: How Owners Found and Fixed the Leak

Owners use the way the car settles as the first clue. A 2013 P85 that dropped evenly at both rear corners overnight, and was sitting on the ground after a week, refilled as soon as it was woken ^[2]. The rule of thumb in that thread: a single low corner usually means a single leaking strut, while both ends dropping or random drops suggest the compressor or valve block ^[2].

Not every noise is a leak. One owner chasing a repeated compressor cycle with a whoosh at the end learned that the whoosh is often the air dryer purging, and painter’s tape marks on the fenders showed no corner was actually sagging overnight ^[6].

The cheapest diagnostic in every thread is a spray bottle of soapy water. One 2013 owner heard air escaping in a quiet garage after driving in the rain and found heavy bubbling at the bottom of both rear springs, where the rubber sleeve meets the metal flange ^[1]. Others sprayed the strut bottoms, air lines and fittings and watched for bubbles ^[2][4].

Do it with the car standing on its wheels. Lifting the car unloads the springs and can hide a leak that only opens under weight ^[2].

Two owners whose compressors ran constantly traced the leak to a plastic tee connector in the air lines rather than a strut ^[3]. Another, who had already replaced the compressor, valve block, both front springs, the tee and the relay, used a bypass hose and a valve-block swap to isolate the fault, and found that the aftermarket valve block itself leaked. With the original block refitted, all four corners held overnight ^[4].

On a 2014 P85D with a persistent red EAS_w007 alert and a low front end, the owner checked fuse F36 and swapped relays K11 and K15 with no change. With help from the forum he found that the compressor’s 40A feed fuse, F82, in a second fuse bank hidden near the cabin filter, had blown. A $5-class 40A MIDI fuse and a reboot brought the compressor back after about six hours of DIY diagnosis ^[5]. A later owner with the same blown fuse also replaced the compressor and then needed Tesla’s service tool to clear a compressor lockout ^[5].

When a strut really is leaking, owners bought used OEM parts or new aftermarket ones. A used OEM rear strut ran about $500 on eBay with about $130 of independent shop labor ^[2]. One owner has run an Arnott rear strut for a year with a normal ride ^[3]. Watch the part numbers: front air springs differ between RWD (for example 6006351-00-D on 2012–2015 cars) and AWD (6006351-00-A), and aftermarket cross-references are not always right ^[3].

Compressors are a common DIY swap. One owner fitted a used compressor for about $125 and has driven about 60,000 miles on it ^[6]. Another fitted a rebuilt compressor and still got a red error with no pump running, so confirm the fuse and relay first ^[6].