News & Updates

12th May 2020

IMPORTANT UPDATE – Preventive Maintenance

Techni has been made aware following several field visits to repair customers vehicles that Techni/Original/VMAC VRlite, VR30, VR40 & VR70 systems are being serviced to a substandard, utilising non genuine parts and in some cases parts not being changed at all, including safety related items.

If you are worried that have or could be effected by this the please see below a number of things to look out for during your system service.

The Automatic Tensioner

The belt tensioner is one of the most important parts to change on your systems, the job of the tensioner is to ensure that the belt always maintains the perfect amount of tension while the system is in use.

  • If the belt tension is too low, the belt will slip causing noise, extremely high temperatures and premature belt wear, all of which can lead to the poor functioning of the belt-driven accessories.
  • If the tension is too high, this will cause excessive wear to the belt-driven accessories.

How often should the Automatic Tensioner be changed?

  1. EVERY service
  2. The tensioner is changed if the belt is changed

What happens if the tensioners are not changed at the correct intervals?

  1. Snapped and frayed belts
  2. The belt jumping onto the wrong pulley groove causing the groove to be “cut off”.
  3. If the tensioner is worn the belt will become to lose and start to slip, this will ultimately end up damaging the compressors clutch.

The pulley on the tensioner should be smooth and level. Any signs of damage, uneven wear, debris or excessive movement require the tensioner to be replaced.

Damaged uneven wear and debris on pulley

Smooth and level tensioner surface


The Drive Belt

The belt that drives the whole system is arguably the most crucial part within the auxiliary drive. It drives the whole compressor from the crankshaft and unlike a standard drive belt, it is constructed of multi-ribs which are made using advanced tensile cord materials, providing the necessary strength and durability.

How often should the Drive Belt be changed?

  1. EVERY service
  2. The belt is changed if the tensioner is changed

What happens if the drive belt is not changed at the correct intervals? 

  1. Cracking
  2. Loss of ribs
  3. Fraying
  4. Snapping causing complete failure

In almost every case we have seen the compressors drive belt fail due to a lack/improper servicing and preventative maintenance due to tensioners. It is also very common that other components are damaged when a belt rotating at high speed fails.

Drive Belt Grooves

Drive Belt Edge


System Filters

All VRlite, VR30, VR40 & VR70 engine mounted compressed air systems have three filters

  1. Spin-On Oil Filter
  2. Air Filter
  3. Coalescing Filter

How often should the ALL Filters be changed?

  1. EVERY Service
  2. If the wrong oil has been used and the system not been flushed

Spin-On Oil Filter

It designed to trap and capture debris and solid contaminants that maybe in the oil passing through it.

What happens if the Oil Filter is incorrectly/ not changed at the correct intervals? 

  1. Aftermarket filters allowing much larger particles to pass through it, at a rate of over than 100% time more than our OEM filter.
  2. Loose aftermarket filters causes oil leakage.
  3. No silicone cap fitted causes severe corrosion.

All of this will weaken the structural integrity of the filter leading to failure. Corrosion will eventually lead to the compressor oil over 80 Degrees Celsius and under pressures of up to 175psi being released with a potential to cause severe personal injury.

Oil Filter should ALWAYS be white


Black Filter


Black Filter


White Filter

Clear Cap


White Filter

Black Cap


The Coalescing Filter

The coalescing filter is to act as a secondary oil separator within the AOST (Air Oil Separator Tank). This happens in the second chamber of the AOST tank. Unlike the air and oil filter whose primary purpose is to stop particles from moving with the system, the coalescing filter has the additional requirements of making the drops of oil coalesce into larger drops and provide a means for them be collected and feedback to the compressor. 

What happens if the Coalescing Filter is incorrectly/ not changed at the correct intervals? 

  1. The filter gets blocked stopping oil return to the compressor resulting in seizure (a very expensive mistake!)

The use of incorrect oil can also affect performance and in certain cases, we have found the coalescing filter to be blocked due to poor maintenance or non-replacement.

Coalescing Filter should not be blocked

The Air Filter

The air filter prevents any debris (dirt, dust, leaves, etc) being drawn into the compressor system. A hardened plastic housing with a corrugated dry paper particulate filter (typically 5-10 micron filtration). Air is drawn in underneath the filter housing. As the air passes from the outside to the centre of the filter it passes through the fine paper element gauze where any impurities such as dust particles, road dirt, are caught before the air enters the compressor system.

What happens if the Air Filter is incorrectly/ not changed at the correct intervals?

  1. Drastic reduction in the amount of air the system can intake
  2. Low pressure in the compressor adding additional strain on the whole system
  3. Reduction in system performance

Air Filter flow maintains performance

Compressor Oil

The VRlite, VR30, VR40 & VR70 are rotary screw air compressor and require oil to function, this is to lubricate the compressor while the ASOT separates the oil and air. The type of oil the Compressor requires is as important as the type of oil your car or van engine needs and the oil made specifically for VMAC air compressors – you wouldn’t put hydraulic oil in your engine.

How often should the Compressor Oil be changed?

  1. EVERY Service
  2. Top up there has been any leakage

What happens if the wrong oil is used in the system?

  1. ALL warranty is void
  2. Reduction in reliability in all VRlite, VR30, VR40 & VR70 Systems
  3. Incompatibility with system seals causing hardening or decomposition causing component failure and system blockage
  4. Foaming oil causing system to overheat and damage the compressor.

Seal Corrosion

Safety Relief Valve

Fitted to the AOST end cap is the pressure relief valve. The purpose of the pressure relief valve is to prevent system pressure exceeding 200psi. It is designed or set to open at a predetermined set pressure to protect pressure vessels and other equipment from being subjected to pressures that exceed their design limits.

When the set pressure is exceeded (200psi), the relief valve becomes the "path of least resistance". As the valve is forced open a portion of the compressed air is diverted through the relief valve to the atmosphere.

How often should the Safety Relief Valve be changed?

  1. EVERY Service

What happens if the Safety Relief Valve is incorrectly/ not changed at the correct intervals? 


Clean & Unblocked

Dirty & Corroded

Fully Trained System Specialist Engineers

Our fully trained systems engineers are specialists in the Techni VMAC product range including VRlite, VR30, VR40 & VR70. Their high level of expertise allows them to diagnose issues outside the scope of a service, above and beyond your generic service engineer.

As specialists in preventive maintenance their knowledge ensures your system performs under optimum working conditions, and by ensuring your system is serviced correctly, will eliminate any safety-related concerns, inconvenience, and costly repairs.

A planned preventive maintenance service may cause a small hindrance for a couple of hours, but compared to actual downtime caused by a breakdown, its incomparable.

We estimate a mobile tyre service vehicle off the road could cost your business on average around £500.00 - £850.00 per day.

You should always check and follow your air compressor manufacturer’s service maintenance schedule, when applicable. For example, the VRlite, VR30, VR40 & VR70 should be serviced every 12months, 400hours or 25,000 miles (40,234 km), whichever comes first.


Contact us today to find out more about your system's maintenance.

+44 (0) 1743 443 176