METClean DPF clean record card

MET CLEAN DPF Clean Record Card

What the Clean Record card is

The Clean Record is the paper trail that turns a cleaned filter into a documented job. It is completed by the operator at the point of clean and travels with the refurbished DPF back to the customer, so there is a clear, honest record of exactly what was done and when. For a busy workshop that cleans filters day in, day out, this is the difference between a filter that simply looks better and a filter that carries genuine provenance.

The front of the card captures the working detail: date and time, the pre-test result in millibars, the DPF make and model, whether the filter came off clean or damaged, the operative company name, the customer, and which MET CLEAN machine the filter was processed on. The reverse sets out, in plain language, why no post-clean pressure figure is issued and what the customer must still do before the vehicle is signed off. Handed over together, the two sides give the end customer a record they can trust and protect the operator from any later dispute about the condition of the part.

Why no post-test figure is provided

This is the point most cleaning services get wrong, and it is stated openly on the card. A filter that has just been washed is still partially damp, and no cabinet machine can fully dry the substrate. Water sitting in the channels changes the way air flows through the monolith, so any pressure reading taken straight after a clean is skewed by moisture rather than by the true state of the filter.

Comparing that damp reading against a dry pre-clean figure is not a like for like comparison, so a headline post number would flatter the result and mislead the customer. Instead the clean is verified visually, with the wash water running from heavy black soot and terracotta ash through to clear water. The only accurate post-clean test is on the vehicle, once the filter is refitted and brought up to operating temperature, where the differential pressure sensor reads a dry filter under real exhaust flow. Being upfront about this is a mark of a professional operation, not a shortcoming.

The clean does not fix underlying faults

A blocked DPF is a symptom, not the disease. The card makes this explicit so the message reaches the customer as well as the operator. Excess soot loading points to a combustion or driving problem upstream of the filter, whether that is worn or leaking injectors, a sticking EGR valve, tired glow plugs, faulty boost, MAF or MAP sensors, or simply a vehicle that only ever does short cold journeys and never completes a regeneration. If the root cause is left in place, the freshly cleaned filter will load up and block again, and the clean will be blamed unfairly.

Just as important, the filter must be reset with a diagnostic tool to 0 per cent soot and 0 per cent ash after refitting. If the calculated soot and ash values are left where they were, the ECU still believes the filter is full and will keep forcing regeneration cycles against a filter that is now clean, wasting fuel, diluting the oil and driving up exhaust temperatures for no reason. A clean, a repair and a reset are three separate steps, and all three are needed to hand a vehicle back properly.

Completing the card at the point of clean

Fill the card in as the job happens rather than from memory afterwards. Record the pre-test result in millibars before the filter goes into the machine, note the DPF make and model, and tick the filter condition honestly. A cracked or melted substrate that comes off the vehicle damaged should be flagged as damaged, not washed and quietly passed on, because a compromised filter will not seal or perform no matter how clean it looks. Add the operative company name and the customer, then tick the MET CLEAN machine used, XL, S, E, V or LITE, so the record reflects the exact process that filter went through.