NHC MOTORS · SERVICE RECORD
Mercedes-Benz E450 after purchase: radiator replacement and new-tyre RFV checks
Where should maintenance start after buying a used car? This E450 visit included a genuine radiator, cooling-system service and fluids. All four tyres were replaced, their RFV readings were addressed, and the work finished with alignment and another road test.
2020 Mercedes-Benz E450 4MATIC · 17,340 km (as of the Sep 17 work report) · first full service after purchase, Sep 16–19
Genuine radiator replacement with cooling system flush and vacuum check, brake fluid and engine oil exchange, A/C refrigerant recovery and recharge, four Michelin CrossClimate 3 Sport tires with RFV matching, four-wheel alignment
Toe and thrust angle brought into specification, RFV within the 6.8 kg limit on all four wheels, reduced noise confirmed on a re-drive of the same route · rear camber left/right difference to be monitored
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Genuine Radiator Replacement and Cooling System Flush
We removed the existing radiator, installed a new genuine Mercedes-Benz unit and flushed the cooling system.
Before filling, we checked that the system held vacuum and then added WÜRTH SI-OAT coolant. Coolant level and connection condition will be checked during subsequent maintenance.
What does coolant replacement involve? Read about draining, flushing and filling. →
Coolant filling after the vacuum check
Workshop recording from this visit.
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Brake Fluid, Engine Oil and A/C Basics
The brake-fluid reservoir was cleaned before an equipment-assisted fluid exchange. Engine oil was replaced with a RAVENOL product, and the filters were inspected.
Refrigerant was recovered and recharged as part of the radiator work. Recording the items and dates makes later maintenance easier to plan around time in use and vehicle condition.
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Michelin CrossClimate 3 Sport Fitment and RFV Matching
All four tires were replaced with Michelin CrossClimate 3 Sport: 245/40R19 98Y XL up front and 275/35R19 100Y XL at the rear — a staggered setup with wider rear tires.
After fitting the new tyres, we checked weight balance and RFV. RFV measures force variation under roller loading; correcting the balance weights does not automatically correct that variation.
New tires vary from one unit to the next. Tires that measured high were given a bead massage and re-measured, and where needed we match-mounted the tire to the wheel. The final RFV readings were 3.5 kg front left, 6.5 kg front right, 5.5 kg rear left and 3.5 kg rear right — all four within our 6.8 kg target limit.
BMW X6: increased vibration after new tyres required wheel inspection as well. →
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Four-Wheel Alignment – Toe and Thrust Angle
Front toe was 2.6 mm left and 3.0 mm right, above the displayed 0.2–2.3 mm range. Rear-left toe was 0.3 mm, below its displayed 0.6–4.4 mm range.
After adjustment, front toe was 1.1 mm each and rear toe 2.3 mm each. The thrust angle changed from -0.04° to 0.00°.
Rear camber was -1.33° left and -0.95° right. Suspension parts were not replaced during this visit; tyre wear and driving behaviour will be reviewed at later checks.
Before adjustment
Toe readings · mm
After adjustment
Toe readings · mm
Toe direction and differences are exaggerated at the same scale in both views. Green: within the displayed toe range; red: outside. Camber is shown separately in the table.
| Wheel | Toe before (mm) | After (mm) | Camber before (°) | After (°) |
|---|---|---|---|---|
| Front left | 2.6 | 1.1 | -0.87 | -0.84 |
| Front right | 3.0 | 1.1 | -0.57 | -0.49 |
| Rear left | 0.3 | 2.3 | -1.38 | -1.33 |
| Rear right | 1.4 | 2.3 | -0.93 | -0.95 |
Caster L/R: 9.00° / 9.23° → 8.96° / 9.20°. Thrust angle: -0.04° → 0.00°.
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Re-Drive Results and Remaining Care
The car was driven again on the same route after the work. The technician noted less road noise.
The remaining left-to-right rear camber difference will be reviewed alongside tyre wear. Coolant level and connections will also be checked following the radiator replacement.
DB11 inspection: see how immediate work and items to monitor were separated. →
Frequently asked questions
The tires are brand new — why measure RFV?
Even new tires vary from unit to unit. RFV measures how the force a tire produces changes under load, which is a separate item from weight balancing. On this car, bead massage and match-mounting brought all four wheels within the 6.8 kg limit.
Is it okay to leave the rear camber difference as it is?
In this service we brought toe and thrust angle into specification without replacing any suspension parts. We will check at the next inspection whether the rear camber difference leads to uneven wear or pulling, and advise on adjustment options if symptoms appear.
See related NHC workshop videos
Related NHC workshop and guide videos; vehicles may differ from this case.
Bought a used car and unsure what to service first?
Send your model, mileage and available service records. We will help identify which cooling, fluid and tyre items need inspection and which records need checking. Book a visit so we can inspect the car and explain the work and cost.
We explain the scope and cost before proceeding with your agreement.
Call 031-258-1617Book on Naver031-258-1617 · NHC MOTORS, Suwon · By appointment