The handbrake issue has been the German team's bugbear through the start of what has otherwise been a vastly successful debut season for the new car.
Having run all three factory Polos with a hydraulic handbrake for the first time on the last WRC round in Greece earlier this month, Sebastien Ogier and Jari-Matti Latvala's cars will revert to the pneumatic system in Italy.
"We had some issues with the hot weather and the hydraulic system in Greece," said Latvala. "The system itself is now working with the hydraulic, but the next thing we have to do is to try and keep the system cool - cooling is what we need to sort out now."
The pneumatic system is slower, but generally more reliable, than the hydraulic version, although it was the pneumatic handbrake that almost cost Ogier victory in Portugal, when the system developed a leak.
At the end of the Acropolis Rally, Volkswagen's technical chief Francois-Xavier Demaison said he was ready to sacrifice some of the performance of the handbrake for better reliability.
This week's Sardinian-based Rally Italy will be the hottest event of the season so far, with temperatures already rising above 30 degrees.
The handbrake is a vital tool in the World Rally Car on some of the tightest and most technical stages of the year.