SL/R230: Brake fluid change - not flush
Thread Starter
Member
Joined: Feb 2020
Posts: 115
Likes: 9
From: Los Angeles
2009 SL550
Brake fluid change - not flush
Hi all,
Having researched this a bit, doing a full break fluid flush is quite involved and I'm not ready to do this yet.
Is it beneficial if I only drain the reservoir (leaving a bit of fluid so as to not cause air bubbles) and then just top up with fresh fluid to the proper level? Is this considered useless or is it good enough? Perhaps I could do just that and in 6 months do the same when the fluid has had some chance to move around?
Also is there much difference between Dot 4 and Dot 4+? Should I use one over the other? I have an 2009 SL550.
Thanks
Having researched this a bit, doing a full break fluid flush is quite involved and I'm not ready to do this yet.
Is it beneficial if I only drain the reservoir (leaving a bit of fluid so as to not cause air bubbles) and then just top up with fresh fluid to the proper level? Is this considered useless or is it good enough? Perhaps I could do just that and in 6 months do the same when the fluid has had some chance to move around?
Also is there much difference between Dot 4 and Dot 4+? Should I use one over the other? I have an 2009 SL550.
Thanks
Hi all,
Having researched this a bit, doing a full break fluid flush is quite involved and I'm not ready to do this yet.
Is it beneficial if I only drain the reservoir (leaving a bit of fluid so as to not cause air bubbles) and then just top up with fresh fluid to the proper level? Is this considered useless or is it good enough? Perhaps I could do just that and in 6 months do the same when the fluid has had some chance to move around?
Also is there much difference between Dot 4 and Dot 4+? Should I use one over the other? I have an 2009 SL550.
Thanks
Having researched this a bit, doing a full break fluid flush is quite involved and I'm not ready to do this yet.
Is it beneficial if I only drain the reservoir (leaving a bit of fluid so as to not cause air bubbles) and then just top up with fresh fluid to the proper level? Is this considered useless or is it good enough? Perhaps I could do just that and in 6 months do the same when the fluid has had some chance to move around?
Also is there much difference between Dot 4 and Dot 4+? Should I use one over the other? I have an 2009 SL550.
Thanks
just doing this without bleeding is a loss of time and has NO effect
it will not "move around"
you can use dot 4+ if you originally have dot4
Member
Joined: Sep 2019
Posts: 230
Likes: 87
From: Northwich
R230 350SL
Im going to assume from your post that you are actually due a brake fluid flush?
It isn’t going to help you. You will still have old fluid in all the lines. Old fluid absorbs moisture, which affects compressibility and will effect your braking power.
Long term and in the extreme that moisture can start corroding stuff too.
Don’t take the short cut, do a proper full flush. It’s not like it has to be done every day, once done it won’t need it again for a couple of years.
It isn’t going to help you. You will still have old fluid in all the lines. Old fluid absorbs moisture, which affects compressibility and will effect your braking power.
Long term and in the extreme that moisture can start corroding stuff too.
Don’t take the short cut, do a proper full flush. It’s not like it has to be done every day, once done it won’t need it again for a couple of years.
Member
Joined: Jan 2011
Posts: 103
Likes: 7
From: Arlington TN
2005 SL500
I heard the brake systems are ultra-sensitive on SL's and you will get errors while flushing the brake fluid. If this is not the case, I can DIY and save some money. Do you have to use the Motive bleeder system or can you use
any compatible bleeder system on my SL?
any compatible bleeder system on my SL?
Super Member
Joined: Jul 2014
Posts: 992
Likes: 245
From: Tucson, AZ
'20 X5 M50i; '17 Ram 3500; Golf Cart; Bikes; Scooters
The key is putting the car to sleep, and keeping it asleep, while working on the SBC system.
Attached are some informative files, and the method used for brake work WITHOUT SDS, which is perfect for DIY.
Follow it carefully or results will not be pretty, or worst case - harmful to your health. You have been warned.
Note that I have done this numerous times and it really is not a big deal.
Just don't wake up the car...simple. Put the car asleep and move the keys to your bedroom under your pillow. It will not wake up.
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Thread Starter
Member
Joined: Feb 2020
Posts: 115
Likes: 9
From: Los Angeles
2009 SL550
Thank you all for your advice: I'll have to do a proper flush then.
I saw a few online videos (although I couldn't find any new ones for a post 2009 SL550) and I admit I am a bit daunted by it being new to DIY. I'll buy the proper tools and give it a go.
I have the Foxwell N530, so I'll need to find the function to disable the brakes if it's available.
thanks again.
I saw a few online videos (although I couldn't find any new ones for a post 2009 SL550) and I admit I am a bit daunted by it being new to DIY. I'll buy the proper tools and give it a go.
I have the Foxwell N530, so I'll need to find the function to disable the brakes if it's available.
thanks again.
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Junior Member
Joined: Mar 2014
Posts: 23
Likes: 8
From: Briarcliff, Texas
2007 Mercedes SL600
Many thanks for the informative information provided.
I have a 2007 SL600.
1. Raise the hood, car sets for several hours.
2. Car keys hidden under my pillow.
Safe now to hook up the Motive Brake Bleeder and bleed brakes?
No need to use SDS system?
I have a 2007 SL600.
1. Raise the hood, car sets for several hours.
2. Car keys hidden under my pillow.
Safe now to hook up the Motive Brake Bleeder and bleed brakes?
No need to use SDS system?
Super Member
Joined: Jul 2014
Posts: 992
Likes: 245
From: Tucson, AZ
'20 X5 M50i; '17 Ram 3500; Golf Cart; Bikes; Scooters
The instructions in the docs say "roll down the window, then lock the car" to prevent someone opening the door and waking the car.
Having the window down allows access to the ignition (without opening the door) to turn the key on (when done) and do the left side wheel spinning that will reset the SBC.
Read the instructions and have a copy at the workspace when doing the work.
Afterwards...Go buy cases of wine with the money saved. Savor your new skills. Be more attractive to the opposite sex. Enjoy life and the pursuit of happiness. You have earned it.
Super Member
Joined: Jul 2014
Posts: 992
Likes: 245
From: Tucson, AZ
'20 X5 M50i; '17 Ram 3500; Golf Cart; Bikes; Scooters
For my foreign friends who cannot translate the PDF docs:
The most important thing is to put the car to sleep first.
Open the engine hood.
Roll down the driver window
Lock the doors and the car with the remote key.
Put your keys inside the house under your pillow
Wait 10 minutes, and the car is asleep.
Do not open the doors or trunk! Keep the car sleeping.
Bleed the brakes with your pressure bleeder.
When done, you have to put the key in the ignition without opening the door.
Turn the key to position 2 but do not start the car.
Rotate both the left side wheels a couple revolutions and within 30 seconds of each other.
Turn the key off, then unlock and open the door.
Finito! You are done!
The most important thing is to put the car to sleep first.
Open the engine hood.
Roll down the driver window
Lock the doors and the car with the remote key.
Put your keys inside the house under your pillow
Wait 10 minutes, and the car is asleep.
Do not open the doors or trunk! Keep the car sleeping.
Bleed the brakes with your pressure bleeder.
When done, you have to put the key in the ignition without opening the door.
Turn the key to position 2 but do not start the car.
Rotate both the left side wheels a couple revolutions and within 30 seconds of each other.
Turn the key off, then unlock and open the door.
Finito! You are done!
Senior Member
Joined: Nov 2008
Posts: 324
Likes: 37
From: Wichita
Plays With Cars
I'm not familiar with that specific tool, but it looks just like the Motive bleeder that I have. Just make sure you get one that has the correct cap to fit a Mercedes, which also fits basically every other European car like BMW, Porsche, Audi, etc. US made cars have a different cap design, as do some Japanese.
Member
Joined: Jan 2011
Posts: 103
Likes: 7
From: Arlington TN
2005 SL500
My intention is to jack up one wheel at a time and bleed instead of putting the whole car on jackstands. This might be a dumb question, but do I have to put the car in neutral in order to rotate the back wheel??
Super Member
Joined: Jul 2014
Posts: 992
Likes: 245
From: Tucson, AZ
'20 X5 M50i; '17 Ram 3500; Golf Cart; Bikes; Scooters
Member
Joined: Jan 2011
Posts: 103
Likes: 7
From: Arlington TN
2005 SL500
Well, I guess I have one, because every year i remove my wheels to clean the brake dust that accumulates on the
inside of the rims, and both rear wheels are locked when I take the tires off the hub. Do I need to apply a little force or should they
roll freely? I don't want to do the job and get stuck because I can't "spin" the rear wheel. BTW, I have a 2005 SL500.
inside of the rims, and both rear wheels are locked when I take the tires off the hub. Do I need to apply a little force or should they
roll freely? I don't want to do the job and get stuck because I can't "spin" the rear wheel. BTW, I have a 2005 SL500.
Super Member
Joined: Jul 2014
Posts: 992
Likes: 245
From: Tucson, AZ
'20 X5 M50i; '17 Ram 3500; Golf Cart; Bikes; Scooters
Well, I guess I have one, because every year i remove my wheels to clean the brake dust that accumulates on the
inside of the rims, and both rear wheels are locked when I take the tires off the hub. Do I need to apply a little force or should they
roll freely? I don't want to do the job and get stuck because I can't "spin" the rear wheel. BTW, I have a 2005 SL500.
inside of the rims, and both rear wheels are locked when I take the tires off the hub. Do I need to apply a little force or should they
roll freely? I don't want to do the job and get stuck because I can't "spin" the rear wheel. BTW, I have a 2005 SL500.
The SBC tends to clamp the brakes when awakened, which may contribute to your issue. See if you can keep the car asleep.
Then you might need a little force to overcome the friction in the drive and brake systems.
You could also jack the rear of the car from the differential (if you can reach it) and that should allow the wheels to spin.
Factory locking differentials were a rare expensive 030 performance option, and aftermarket diff would be costly for this car, so I don't think you have one.
To be honest, I think you could get the SBC brakes to work without spinning the left side wheels, but that is what the factory wants you to do.
Senior Member
Joined: Nov 2008
Posts: 324
Likes: 37
From: Wichita
Plays With Cars
Well, I guess I have one, because every year i remove my wheels to clean the brake dust that accumulates on the
inside of the rims, and both rear wheels are locked when I take the tires off the hub. Do I need to apply a little force or should they
roll freely? I don't want to do the job and get stuck because I can't "spin" the rear wheel. BTW, I have a 2005 SL500.
inside of the rims, and both rear wheels are locked when I take the tires off the hub. Do I need to apply a little force or should they
roll freely? I don't want to do the job and get stuck because I can't "spin" the rear wheel. BTW, I have a 2005 SL500.
Member
Joined: Jan 2011
Posts: 103
Likes: 7
From: Arlington TN
2005 SL500
Senior Member
Joined: Nov 2008
Posts: 324
Likes: 37
From: Wichita
Plays With Cars
Yes, the car should be in neutral to spin the rear wheels. In park the parking pawl engages and locks your transmission into place, hence why the wheels don't spin.
Senior Member
Joined: May 2019
Posts: 280
Likes: 37
From: Lincolnshire, IL
2005 SL55 AMG
I’m confused. I bled using the Motive pressure bleed system. However, without SDS, doesn’t a substantial amount of old fluid remain in the SBC module, even if “asleep”? Since the fluid was so filthy, I ended up bringing it to my Indy, who did a full flush using SDS.
