Mercedes Benz B Class car check
Find out if a B Class has outstanding finance, has been written off or stolen, how many owners it’s had, and which known problems apply to the generation you’re looking at.
Finance, stolen, write-off and owner history data provided by Experian. Results in under a minute.
- Typical price
- £12,454267 at dealers
- MOT failure rate
- 20.3%249k tests
- Known problems
- 5across W245 to W246
- Full report
- £7.49one-off, no subscription
Which B Class are you looking at?
Each B Class generation has its own weak spots. Pick the one you’re viewing to see what to check.
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Brake hose deterioration
Safety risk W245, W246Flexible brake hoses on B Class models show excessive deterioration, cracking, and stretching at rates far above the fleet average. The hoses connect rigid brake pipes to the brake calipers and must flex with suspension movement. When they fail, brake fluid leaks out and braking performance is severely compromised. This affects all engine variants across all mileage bands including very low-mileage examples, suggesting a material or design issue with the hose specification.
What to check: Inspect all four brake hoses where they connect to the brake calipers at each wheel. Look for any cracking, bulging, or weeping brake fluid around the hose ends and union points. Check the hoses along their length for any visible deterioration, chafing against suspension components, or twisted ro...
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Brake pipe corrosion
Safety risk W245, W246Rigid brake pipes on B Class models corrode at nearly 10 times the fleet average across all mileage bands including very low-mileage examples. The steel brake pipes run from the master cylinder to each wheel and are vulnerable to corrosion from road salt and moisture. Corrosion can cause sudden brake failure when pipes rupture under pressure.
What to check: Look under the car at the brake pipes that run along the chassis rails and to each wheel. Check for any surface rust, flaking metal, or obvious corrosion particularly at connection points and where pipes pass through the bodywork. Pay particular attention to the rear axle area where brake pipes a...
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Fuel system deterioration
Wear item W245, W246Diesel B Class models experience fuel pipe and hose damage at rates over 40 times the fleet average, particularly from 60,000 miles onwards. The fuel system includes both rigid pipes and flexible hoses that connect the fuel tank to the engine. Deterioration appears linked to diesel fuel chemistry or system pressure characteristics specific to these engines.
What to check: Check around the fuel filler area for any smell of diesel or visible staining that could indicate leaks from fuel lines. Look under the rear of the car near the fuel tank for any wet patches or diesel smell. Check the engine bay for any visible fuel lines and look for signs of weeping or staining...
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Suspension joint dust cover failure
Wear item W245, W246B Class models show exceptionally high rates of suspension joint dust cover deterioration, failing at over 25 times the fleet average. These rubber boots protect ball joints, track rod ends, and CV joints from dirt and moisture ingress. Once damaged, contamination enters the joint leading to accelerated wear and eventual replacement of the entire component.
What to check: Inspect all visible suspension components around both front wheels for torn, cracked, or missing rubber dust covers on ball joints and track rod ends. Check CV joint boots on the driveshafts - these are large accordion-style rubber boots visible behind each front wheel. Look for splits, tears, or...
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Engine mount deterioration
Wear item W245, W246Petrol B Class models experience engine mount failure at nearly Engine mounts use rubber-to-metal bonding to isolate engine vibration from the chassis. Failure causes excessive engine movement, transmission of vibration to the cabin, and potential damage to connected pipes and cables.
What to check: Open the bonnet and visually inspect the top engine mount (visible at the front of the engine bay). Look for any separation between rubber and metal, cracking in the rubber, or obvious sagging. Check that the engine sits level and is not tilted to one side which would indicate a collapsed mount.
We haven’t flagged any common problems for this generation in our data yet. A history check still tells you about finance, write-offs and theft, and the MOT history shows how this particular car has been looked after.
What B Class cost at dealers now
From 267 used B Class we track on UK dealer websites.
- Typical asking price
- £12,454
- Typical mileage
- 49,437 miles
- Price change vs last month
- -4.7%
B Class MOT results
of B Class MOT tests end in a fail, from 248,987 tests.
Most common reasons for failing
- No specific defect data available
Check the B Class you’re buying
One report covers outstanding finance, write-offs, theft and previous owners from Experian, plus MOT history, mileage and the known problems for its generation.
Finance, stolen, write-off and owner history data provided by Experian.
What the check includes
- Outstanding finance Experian
- Write-off status Experian
- Stolen vehicle check Experian
- Previous owners and keeper history Experian
- MOT history and advisories DVSA
- Mileage check DVSA
- Known problems for its generation GetCarWise
- How many are left on the road DVLA
B Class questions
Is the Mercedes Benz B Class reliable?
20.3% of B Class models fail their MOT based on 248,987 tests analysed. That’s about average for the class. There are 5 known problems to watch for, the most serious being brake hose deterioration. A full history check shows whether a specific car has had related write-offs or insurance claims.
What are the main problems with a Mercedes Benz B Class?
The most serious known issues are brake hose deterioration, brake pipe corrosion, fuel system deterioration. Problems vary by generation, so check which apply to the year you’re looking at. Our car check flags whether a specific B Class has been written off or had insurance claims linked to these faults.
How do I check if a Mercedes Benz B Class has outstanding finance?
Enter the registration on this page. We query Experian’s finance database and return any outstanding agreements within a minute. If finance is still owed, the finance company can legally repossess the car even after you’ve paid the seller. At £7.49 it’s the cheapest way to avoid a car that isn’t legally for sale.
How do I check if a Mercedes Benz B Class has been written off?
Our check queries Experian’s insurance write-off database for Cat A, B, S and N markers. A Cat S or N B Class has been structurally or non-structurally damaged and repaired. This doesn’t mean it’s unsafe, but it affects resale value and some insurers won’t cover it. The check costs £7.49.
Can I check a Mercedes Benz B Class for free?
You can check MOT history free on GOV.UK, which shows past test results and advisories. What it won’t show is outstanding finance, write-offs or theft markers, which are the things that actually cost you money after you’ve bought. Our full check adds all of that for £7.49, using Experian data.
Is a Mercedes Benz B Class HPI check worth it?
HPI is one brand of car check. Our check uses the same Experian data covering finance, stolen, write-off and keeper history, plus MOT analysis and known B Class faults that HPI doesn’t include. At £7.49 it’s typically less than half the price of an HPI check.
More on the B Class
Other Mercedes Benz car checks
Finance, stolen, write-off and owner history data provided by Experian. MOT data from DVSA. Known problems from GetCarWise analysis. Updated October 2026.