NHC MOTORS · SERVICE RECORD
BMW X5 M50d F15 coolant connection repair and rear air-spring replacement
We removed the intercooler and intake manifold to reach the coolant connection behind them, then replaced the connecting pipe and seals. Intake deposits were cleaned separately, and both rear air springs were replaced with OEM parts.
On this 2018 BMW X5 M50d F15, the coolant connection to be replaced was behind the intercooler and intake manifold. We removed those components to reach the pipe, then replaced the connection and the manifold-joint seals.
Both rear air springs were also replaced with OEM parts.
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Removing the intercooler and intake for access
We removed the upper intercooler and intake manifold in sequence. The coolant connection was hidden behind them; the intercooler was refitted after the work.
Black deposits were visible inside the removed intake. Recirculated exhaust can leave soot in a diesel intake. We cleaned the removed parts and their mating surfaces. This intake work is separate from the coolant repair.
We also carried out HHO carbon cleaning and added BG 245 diesel fuel additive.
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Replacing the coolant pipe and seals
We compared the old connecting pipe with a new part marked 11 12 7 810 707 and replaced it. New seals were fitted at the intake-manifold joint during reassembly.
After reassembly, we connected the service equipment, filled the circuit with AVENO ANTIFREEZE PF A11 and added BG Universal Super Cool. Let us know if the cold coolant level drops again or a joint becomes wet.
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Replacing both rear air springs
We removed both rear air springs and fitted OEM replacements. Each spring carries vehicle weight using compressed air. Pressure must be handled under the vehicle-specific procedure before removal and during filling.
For this job, the scan tool displayed air-emptying instructions and an air-filling stage. Its displayed procedure does not by itself document every completed step or the final ride height.
We also applied a foaming liquid to a removed air spring to inspect where air might escape. We do not infer a measured leak rate from that observation.
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What to watch afterward
For the cooling circuit, check the level with the engine cold and look for wetness around the repaired connection. For the suspension, compare the rear ride height after the vehicle has been parked overnight.
If coolant drops again, the connection needs another check. If the rear settles while parked, we would inspect the air springs and air supply.
X5 cooling-system and rear-suspension work
Intercooler/intake removal and cleaning → pipe/seal replacement → coolant fill
Scan-tool procedure → both rear air springs replaced → air-filling stage
Cold coolant level and joint wetness / rear ride height after parking
Frequently asked questions
Are coolant loss and a change in rear ride height related?
They involve different systems. Coolant loss calls for a cooling-circuit check; ride-height changes call for an air-spring and air-supply check. Both systems were serviced on this X5.
Can an air spring simply be swapped without a scan-tool procedure?
No. It contains compressed air, so the vehicle-specific emptying, filling and compressor-power conditions matter. On this X5, the scan tool displayed emptying instructions and a filling stage while both rear springs were replaced.
Does intake cleaning repair a coolant leak?
No. Cleaning intake deposits and replacing a coolant connection are separate jobs. On this X5, the coolant pipe and seals were replaced independently of the intake cleaning.
Related reading
- Guide
BMW X6 M50d coolant leak, water pump and thermostat replacementA different M50d coolant repair; the fault location here is not assumed to match.
- Guide
Range Rover Vogue air-spring replacement and alignmentA separate air-suspension service with its own follow-up checks.
- NHC video
BMW 5 Series coolant leak while driving
▶ Watch on YouTubeA video about a coolant leak on a different BMW.
Two systems on this X5, two separate checks
For coolant loss, we examine the covered connections and replace the required pipe and seals. If the rear of the vehicle settles after parking, we check the air springs and supply under the scan-tool procedure. Tell us which symptoms you have when booking so we can plan the work.
We explain the work and estimate before proceeding with your consent.
Call for service adviceBook via Naver031-258-1617 · NHC Motors, Suwon · By appointment
Published 2026-09-26