Jump to content
Sign in to follow this  
Stressed

G30/31 Brake pedal "drops"

Recommended Posts

Bought a delivery mileage G31 in August.

When pushing the brake pedal the braking resistance (hight of pedal) is about 20mm higher than the gas pedal height.

A couple of times when pulling away at the start of a journey I brake and the pedal travels further than normal before the brakes work. It drops to level or just bellow the gas pedal.

At first I though it was my imagination. THEN it happened mid journey when braking half way round a roundabout and another journey at about 60mph on the M25. I was NOT impressed at 60 mph.

I'll be taking the car back to BMW tomorrow.

 

Anyone else had this issue with their G30 or G31? Men id the 520d mild hybrid

Share this post


Link to post
Share on other sites

There should be some initial drop on the pedal, otherwise the brakes would be grabby. Even though the pedal drops, is there still feeling of braking or is it as if you have no brakes?

Share this post


Link to post
Share on other sites
1 hour ago, dj1233 said:

There should be some initial drop on the pedal, otherwise the brakes would be grabby. Even though the pedal drops, is there still feeling of braking or is it as if you have no brakes?

Obviously there is the initial travel of the brake pedal that you would expect. BUT the problem is the additional travel of the brake pedal on the occasions described above

Share this post


Link to post
Share on other sites

Are there any similarities in the conditions and events when it did happen? Were the braking incidents quick and harsh which could have kicked the ABS in?

Share this post


Link to post
Share on other sites

No, the occasions when starting the journey have been gentle braking within 20m to 200m from pulling away. The roundabout was normal braking for traffic lights on the roundabout and the M25 was firmer rush hour braking, no where near ABS. My driving style is generally smooth with good forward planning (ex blue light advanced driver)

Share this post


Link to post
Share on other sites

Just a little update!

The pedal dropped again today braking at a roundabout. Then whilst stationary at the lights putting pressure on the brake pedal it gradually sank almost to the floor. The pedal to the floor happens every time stationary pushing on the pedal.

I drove straight in to BMW Harold Wood (was only ½ a mile away), they kept the car and BMW assist supplied me a hire car via Enterprise at BMW's expense. Impressed with BMW customer service, NOT impressed with brake failure on a new car with less than 3000 miles on the clock!

I know have a g30 530e sitting outside! DOn't know what's going to happen when I need the estate space Monday!

Share this post


Link to post
Share on other sites

Pedal sinking slowly under pressure indicates a leak in the system, either external or in the master cylinder. Should not happen on a new car, but even new things break sometimes.

 

 

 

Share this post


Link to post
Share on other sites

Apparently BMW have told the dealer to do a software update then further inspection and testing. They have said there isn't a fluid leak.

I am wondering if there is a software issue with the emergency brake assist. I have had the brakes slam on when going through a gap that I have been trough a number times without out problem. A friend with a new X3 had a few random emergency braking issues. He took it back to BMW, they said no fault found, but had done a software update on his car.

Share this post


Link to post
Share on other sites

I have got the car back from BMW.

I now feel there is a BMW cover up of a brake issue. They gave me a full run down of driving characteristic of a "hard" brake pedal and mild hybrid technology telling me the "Update" has been done. I raised the concern that they have given me a great description of a problem BUT that was not the fault I brought my car in with! They have sent me away with my car stating no fault found.

The update has completely changed the feel of the brake pedal from before even though they tried to say there was NOT a fault. This is not a change in a bad way but feels completely different eg hight braking starts and the progressive way the brakes are applied. BMW  have done this software update to my friends new X3 after he reported un explained emergency braking for the brake assist. Even though they said NO FAULT found.

 

If there was not a fault with my car or his X3 why the update? Are they NOT admitting to a brake issue because it would be a recall and just updating cars when they come in for service or if a customer takes it in for another reason?

 

Unfortunately the update has now stopped the energy recovery  when off the throttle and when braking that charges the 48v system! Looks like the car will have to go back in again!

 

The bakes work OK and the previous fault has not reoccured!

Share this post


Link to post
Share on other sites

The post above was November 2020.

Within a week of the post the brake pedal drop was happening again. Car went in again to Sytner. Eventually Sytner said that BMW was working on another software update. I took until July for the update to arrive. They had the car for 2 weeks testing it and supposedly fixing it to BMW Germany standards! The day after collecting it the brake pedal dropped again.

Totally peed off I studied the Consumer rights act, double checked with citizens advice and formally rejected the vehicle. I was offered a full refund that because of Brexit and the micro chip shortage would not be enough to buy a replacement car. Sytner challenged BMW Germany. BMW then decided to replace the brake servo and master cylinder, still calming there is not a fault with the car.

I picked it up again Friday. Traveled 120 miles today. The car feels like they have upgraded the brakes. The pedal is precise, and it stops so bloody quick I'll have to adjust my braking.

Considering BMW say there is no fault with the brakes and there is now such a massive difference in braking performance, I think BMW have been telling porkies!!!

 

Can't believe BMW Germany have happily been telling Sytner to tell me the car is fine for a year only to find it has had a fault master cylinder/servo all along. Peed off is an under statement, 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×