If you increase the speed, working with the gas pedal, hot air immediately begins to flow into the passenger compartment. This indicates poor circulation of the coolant through the heating radiator. When the revolutions are high enough, that is, above 2000 revolutions, then the coolant pump rotates more strongly and drives the fluid in the system better. Sometimes it happens that moving along the highway, setting a comfortable cabin temperature, you find yourself, for example, in a traffic jam, and cold air begins to flow into the cabin. This, in the end, starts to get bored and prompts to search for a way out of this situation. The best solution would be to install an additional pump that stabilizes the circulating fluid flow through the radiator.

1. TRANSPORTER IV Bus (70B, 70C, 7DB, 7DK, 70J, 70K, 7DC, 7DJ)
2. TRANSPORTER / CARAVELLE IV Bus (70B, 70C, 7DB, 7DK, 70J, 70K
3. TRANSPORTER / MULTIVAN IV Bus (70B, 70C, 7DB, 7DK, 70J, 70K,
4. EUROVAN / CARAVELLE IV Bus (70B, 70C, 7DB, 7DK, 70J, 70K, 7D
5. TRANSPORTER T4 Bus (70B, 70C, 7DB, 7DK, 70J, 70K, 7DC, 7DJ)
6. TRANSPORTER / CARAVELLE Mk IV Bus (70B, 70C, 7DB, 7DK, 70J,
7. CARAVELLE IV Bus (70B, 70C, 7DB, 7DK, 70J, 70K, 7DC, 7DJ)
8. SHARAN (7M8, 7M9, 7M6)
9. ALHAMBRA (7V8, 7V9)
10. PASSAT (3B2)
11. PASSAT Saloon (3B2)
12. TRANSPORTER IV Van (70A, 70H, 7DA, 7DH)
13. EUROVAN IV Van (70A, 70H, 7DA, 7DH)
14. TRANSPORTER T4 Van (70A, 70H, 7DA, 7DH)
15. TRANSPORTER Mk IV Van (70A, 70H, 7DA, 7DH)
16. TRANSPORTER IV Platform/Chassis (70E, 70L, 70M, 7DE, 7DL, 7D
17. TRANSPORTER T4 Platform/Chassis (70E, 70L, 70M, 7DE, 7DL, 7D
18. TRANSPORTER Mk IV Platform/Chassis (70E, 70L, 70M, 7DE, 7DL,
19. PASSAT Variant (3B5)
20. PASSAT Wagon (3B5)
21. See more in applications

The operation of the additional water pump

An HEPU brand Additional Water Pump is necessary for a significant circulation of the coolant in a small and large circle when the thermostat is opened. The good heat dissipation of the stove radiator becomes especially important, and on hot summer days, the improved efficiency of the main radiator will be a wonderful addition.