Brake booster recall and brake fluid loss
Thread Starter
Newbie
Joined: Aug 2023
Posts: 11
Likes: 1
GL 350 bluetec
Brake booster recall and brake fluid loss
Hello,
I own a 2011 GL 350 Bluetec and a few days ago I got the red warning light for low brake fluid level. I filled it up and it seemed to be ok afterwards. Now a few days later the same problem so I must slowly lose brake fluid somewhere. Now my question is could it be brake booster related or just leaking out somewhere else ? The reason I am asking is that about 2 years ago MB issued a recall on the brake booster and asked owners to let them be checked by the dealer. Mine came back with some rust and recheck within 2 years (I haven’t got any notification from the dealer for a re-check yet).
I was thinking to get the car checked by my indy shop or going directly to my dealer, what are your thoughts ?
Thanks for your help !
I own a 2011 GL 350 Bluetec and a few days ago I got the red warning light for low brake fluid level. I filled it up and it seemed to be ok afterwards. Now a few days later the same problem so I must slowly lose brake fluid somewhere. Now my question is could it be brake booster related or just leaking out somewhere else ? The reason I am asking is that about 2 years ago MB issued a recall on the brake booster and asked owners to let them be checked by the dealer. Mine came back with some rust and recheck within 2 years (I haven’t got any notification from the dealer for a re-check yet).
I was thinking to get the car checked by my indy shop or going directly to my dealer, what are your thoughts ?
Thanks for your help !
MBWorld Fanatic!
Joined: Jan 2010
Posts: 3,116
Likes: 782
NGL450 w/EORP, S550
There shouldn’t be any fluid in the brake booster so you probably have a holed brake line somewhere. Look for fluid puddles where you’ve parked.
the failure mode of the booster is rusty is that a strong brake application would separate it from the firewall, Causing loss of brakes and structural damage.
the two issues you’re having I don’t think are related other than possibly both being due to rust.
where do you drive?
the failure mode of the booster is rusty is that a strong brake application would separate it from the firewall, Causing loss of brakes and structural damage.
the two issues you’re having I don’t think are related other than possibly both being due to rust.
where do you drive?
Thread Starter
Newbie
Joined: Aug 2023
Posts: 11
Likes: 1
GL 350 bluetec
To follow up, I ask my indy to check for brake fluid loss and he could not find any. He replaced brake fluid and flushed the system, so far so good.
Now, last week, the problem came back. Although I don’t seem to miss brake fluid, the brake pedal suddenly feels spongy and slowly going to the floor when stopping at a traffic light for example, the car also advances at a stop if I don’t step at the pedal repeatedly and there is like a hissing noise.
My question is again could this be brake booster related and if so will Mercedes change it free of charge due to the recall that was issued ? Mine was inspected and came back as rusted and needs to be re-checked.
Thanks again for any help.
Now, last week, the problem came back. Although I don’t seem to miss brake fluid, the brake pedal suddenly feels spongy and slowly going to the floor when stopping at a traffic light for example, the car also advances at a stop if I don’t step at the pedal repeatedly and there is like a hissing noise.
My question is again could this be brake booster related and if so will Mercedes change it free of charge due to the recall that was issued ? Mine was inspected and came back as rusted and needs to be re-checked.
Thanks again for any help.
Super Member
Joined: Jul 2016
Posts: 703
Likes: 129
From: NE OHIO
1998 SL500,2011 GL550,2009 ML350,past 1995 E320 Cabrio ,2005 ML500,2006 ML500,1996 SL500,1972 280SEL
brake issue
To follow up, I ask my indy to check for brake fluid loss and he could not find any. He replaced brake fluid and flushed the system, so far so good.
Now, last week, the problem came back. Although I don’t seem to miss brake fluid, the brake pedal suddenly feels spongy and slowly going to the floor when stopping at a traffic light for example, the car also advances at a stop if I don’t step at the pedal repeatedly and there is like a hissing noise.
My question is again could this be brake booster related and if so will Mercedes change it free of charge due to the recall that was issued ? Mine was inspected and came back as rusted and needs to be re-checked.
Thanks again for any help.
Now, last week, the problem came back. Although I don’t seem to miss brake fluid, the brake pedal suddenly feels spongy and slowly going to the floor when stopping at a traffic light for example, the car also advances at a stop if I don’t step at the pedal repeatedly and there is like a hissing noise.
My question is again could this be brake booster related and if so will Mercedes change it free of charge due to the recall that was issued ? Mine was inspected and came back as rusted and needs to be re-checked.
Thanks again for any help.
The recall can only be checked by an MB DEALER if you want it fixed for free. I had 4 SUV’s checked and only 1 needed parts replaced… the dealership said they are finding approx 1 out of 5 and we are in the Rustbelt .. NE OHIO
Thread Starter
Newbie
Joined: Aug 2023
Posts: 11
Likes: 1
GL 350 bluetec
Thanks for your reply, I actually trust my Indy shop as they do all my maintenance on the car for years now. I was just wondering if Mercedes will replace all the affected brake boosters eventually. I called them today about the recall and got no answer, more like: check with your dealer. I find that disappointing as they issued the recall and not my dealer and thus should know best what’s included and what not.
Super Member
Joined: Jul 2016
Posts: 703
Likes: 129
From: NE OHIO
1998 SL500,2011 GL550,2009 ML350,past 1995 E320 Cabrio ,2005 ML500,2006 ML500,1996 SL500,1972 280SEL
brake recall
So the rust can cause a vacuum leak which would lead to needing more pressure on the pedal and in really rusted cars possibly mechanical failure because of the hard hitting of the pedal. It’s all in the recall info .
For the complete recall
https://static.nhtsa.gov/odi/rcl/202...4V298-0919.pdf
Last edited by vesiadog; Feb 10, 2025 at 06:52 PM.
Trending Topics
MBWorld Fanatic!
Joined: Jan 2010
Posts: 3,116
Likes: 782
NGL450 w/EORP, S550
Yes, a rusted booster will be replaced
But
replacement boosters that don’t rust don’t exist yet so MBZ aren’t putting any in. They are effectively sidelining all cars with this issue.
But
replacement boosters that don’t rust don’t exist yet so MBZ aren’t putting any in. They are effectively sidelining all cars with this issue.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Thread Starter
Newbie
Joined: Aug 2023
Posts: 11
Likes: 1
GL 350 bluetec
If I understand you well you’re saying that all brake boosters of the cars recalled will be replaced free of charge eventually, but it hasn’t been done yet due to parts unavailability ?
Super Member
Joined: Jul 2016
Posts: 703
Likes: 129
From: NE OHIO
1998 SL500,2011 GL550,2009 ML350,past 1995 E320 Cabrio ,2005 ML500,2006 ML500,1996 SL500,1972 280SEL
Super Member
Joined: Jul 2016
Posts: 703
Likes: 129
From: NE OHIO
1998 SL500,2011 GL550,2009 ML350,past 1995 E320 Cabrio ,2005 ML500,2006 ML500,1996 SL500,1972 280SEL
Parts should be ordered ASAP
I had 4 ML-GL’s checked and only 1 needed changed and updated. Parts were in stock and I am driving that GL now. Not sure you were given the best info. The recall is totally free and parts are available is my experience.
Super Member
Joined: Jul 2016
Posts: 703
Likes: 129
From: NE OHIO
1998 SL500,2011 GL550,2009 ML350,past 1995 E320 Cabrio ,2005 ML500,2006 ML500,1996 SL500,1972 280SEL
recalls
Remember the main issue about Recalls… many are done by the government.NOT ALL . so if your car needs the components they will be free and if you are told that they are not in stock … call the recall phone number ASAP…
Last edited by vesiadog; Feb 12, 2025 at 10:16 PM.
MBWorld Fanatic!
Joined: Jan 2010
Posts: 3,116
Likes: 782
NGL450 w/EORP, S550
my experience was a year ago, and your mileage has clearly varied.
Super Member
Joined: Jul 2016
Posts: 703
Likes: 129
From: NE OHIO
1998 SL500,2011 GL550,2009 ML350,past 1995 E320 Cabrio ,2005 ML500,2006 ML500,1996 SL500,1972 280SEL
question
Did your GL need the booster replaced? Did they tell you how long it would take to get parts? As I stated already we took 4 -164’s into the dealership and they told us they try and keep at least 1-2 parts on hand . They fixed mine same day.. My car had about 80k on it and now has 90k… not sure that matters.
My advice to everyone is get your 164’s checked and it will be taken care of if needed.
My advice to everyone is get your 164’s checked and it will be taken care of if needed.
MBWorld Fanatic!
Joined: Jan 2010
Posts: 3,116
Likes: 782
NGL450 w/EORP, S550
My booster was fine but the Mercedes recall letter and the Service advisor stated that if unacceptable rust was found, the car would not be allowed to be driven home. Exactly how they intended to ensure that was unclear, as well as moot since my booster was fine.
The reason for sidelining the vehicle was that MB did not have an updated part number to install, nor did they want to install the non-updated part for liability reasons. So you would effectively be waiting for MB to update the part.
glad to hear some dealers have updated boosters or are installing the existing part number subject to periodic inspection. As I recall the main issue was that the rubber band around the seal of the two halves was retaining moisture and causing rust. The recall involved removing the rubber band.
The reason for sidelining the vehicle was that MB did not have an updated part number to install, nor did they want to install the non-updated part for liability reasons. So you would effectively be waiting for MB to update the part.
glad to hear some dealers have updated boosters or are installing the existing part number subject to periodic inspection. As I recall the main issue was that the rubber band around the seal of the two halves was retaining moisture and causing rust. The recall involved removing the rubber band.
