ssbreddy

2008 Mercedes Benz R350. Changed the cv axle three months back with an
indy shop. After changing the axle what I am noticing is when I am on a uphill
(even a small angle of 15 degree upwards), and when I engage the gear to drive
mode and press gas pedal the car behaves like I am applying break.

Strange symptom. It does not occur every time but is happening more now.
Ex below,

1. Car parked in drive way which is slight uphill of an angle of 15 degree or less. I
start the car, engage the gear to drive and press the gas pedal. the car
behaves like I applied the breaks. Then it starts to move on. I hear a hissing
sound inside the car near the drives seat.

2. I am driving the car and everything is normal. I come to a stop on a small
uphill for a stop sign. I stop the car by applying break. Now I am already in
drive mode and when I press on gas pedal the car is like again applying
breaks.

No check engine light have come anytime. Can anyone please throw any
light. Is this related to recent cv axle change or completely unrelated.

virgisr

There is that support function on them, where you stop on the slope, the brakes are applied by the car for a short period of time to help you start moving. As if you would be doing same using the hand brake to start moving on the slope.
Possibly this support braking function is malfunctioning on your car?

ssbreddy

I dont think the 2008 R model had that function. This behavior never happened during the use of the vehicle in the last 9 years of the vehicle I owned. All this started after the cv axle joint replacement on the passenger side.

ssbreddy

I took it to the indipendent shop today for dignostic and there is no code and was able to reproduce the issue. They did not notice any leak nor anything unusual. But they recommended to change the transmission fluid. Cost $259. But my fear is that this might not be the issue and it might be something else and we are missing to catch that.

Any one faced similar issues or thaughts.

ssbreddy

Update 10/19/2019:

I took it to the indy shop who replaced the front passanger side axle and the abs speed sensor and told them that it is definately with the sensor acting up. They initially said no error code hence it should be good. But I insisted them to take a look and check the voltage on the sensor. They checked and said that the sensor was the issue and they replaced free of cost and I have the vehicle since two days and all looks good.

Thanks everyone for the wonderful support.

Timpala

Glad you got it fixed. I was about to post that it sounded just like how my 2011 R-350 acted when the ABS sensor failed on the right rear. I have a gravel driveway and it tried to lock the brakes a couple of times, then set the ABS/ESP warning note on the dash display.
I replaced the sensor and the code went away as soon as the car noticed the sensor was giving input again.