I recently bought a GLA, brand new from factory. At the back window, the water comes only after 4-5 second.
The dealer said its normal, but i am pretty sure its not.
Anyone could help me, if their GLA works the same way?
I believe there is still only one pump & reservoir for both the windshield and the liftgate glass washers (valve-diverted dependent on selection). The liftgate is of course a fair distance from the engine compartment and therefore it does take a bit more time for the fluid pressure/volume to be conveyed compared to the windshield washer.
This situation with one tank and two washers, has been common for hatchbacks for a long long time.
They way the delay is overcome is:
Water-based liquids are incompressible at normal temperature. So a column of water is created in the tube that leads to the washer the first time you activate it. Then the tube has on it a non-return ball valve. That prevents the liquid from reversing back into the tank and the second time and on, it sprays almost immediately.
Maybe your car is either missing the non-return valve, or maybe the valve is defective. There certainly would be no electronic report of that.
If somehow there were cost reduction measures on your car, and they didn't have a valve and this is normal, then buy such off of ebay or some site and install it yourself.
A forum community dedicated to Mercedes-Benz GLA owners and enthusiasts. Come join the discussion about performance, features, modifications, classifieds, troubleshooting, maintenance, and more for the 250 4MATIC and AMG 45 4MATIC GLA!