Fifth Ring

... myself (easy as pie) and the car is in the shop today getting the transmission and radiator flushed. H&R springs are also going on.

When under the car doing the brake fluid, I noticed a coating of oily slime covering the bottom of what I believe is the transmission pan (black, flat pan). I'm having it checked today, but it felt/looked like motor oil. I guess it oculd be transmission fluid. I'll hope for the best, but if it's a problem, it'lll be a warranty claim. Given the location, it could be coming from anywhere, and just splattering the bottom of the pan.

splinter

Are you pleased with feel and ride height of your new springs?
Good luck at the track this year, and be safe!

Code3 Performance

I should probably do a brake fluid flush myself. Is it pretty straightforward, just like most cars? Or is there anything that is specific to the MB when doing this. Thanks.

smgC32

could be the power steering pump is leaking and traveled down to that area. Pump is a common failure point. Have a great time at the track. I would flush your fluid after two or three track days depending on how hard you are working the system. some people bleed new fluid into the system after each track event until the bubbles disappear. I like RBF600 and it has worked great for me. Don't bother with Castrol SRF. At $70 a can, it won't last beyond a month sitting around in a daily driver before moisture sets in. ATE supper blue or its yellow brother is just fine as well. In fact the MB fluid has a very high wet and dry boiling point and is one of the best factory fluids which is very similar to ATE's specs. Are you still running stock shocks?

Fifth Ring

Well, I picked up the car last night (dark & rainy) and did not get a great look at it until this morning.

Verdict? So far a B+. With the tallest spring shims in the back, the rear is still a bit low for my taste (maybe 1/2" too low) and the front is just about perfect. I am inclined to withhold final judgment until I've done my track day; and perhaps after the springs "settle" (hoping the rears don't). If I have any doubts or problems with handling, I'm going to punt them back to H&R and get the substitute springs.

Based on this morning's commute, I have to say that I am VERY happy with the ride and the increased firmness. It is by no means harsh, but definitely less floaty. It will pass the wife test -- i.e. the wife won't know the difference.

I will not know until I hit the track how the springs affect turn in and overall balance. My commute is fairly urban and traffic-laden, so I do not get a chance to really test the setup.

Visually, the rears seem to have some negative camber, as do the fronts. I'll call the shop today and see (they were closed when I picked up) what the alignment settings turned out to be.

Pics to come.

Fifth Ring

I went with Ate gold. Great specs for the price.

Still running stock shocks. I was a little worried, but I really like the ride. Probably stupid not to change them at 44,000 miles; but I think I can get another year to 18 months out of them.

Moviela

ATE racing gold and blue are the same fluid. The different colors allow you to easily see when one has flushed the other. Neither fluid is approved for Mercedes cars with ABS. The narow passages in the ABS valve assembly demand a different fluid. ATE does make it, but they don't seem to sell it in the US. The brake fluid sold by Mercedes is the only fluid that is easy to find.

Moisture can enter the brake system of any Mercedes because the tank is vented to the air. A small amount of moisture is acceptable in a daily driver, but is not the reason brake fluid should be changed every two years. It is copper absorbtion that is a greater problem. Most workshops cannot measure the level, so a conservative time interval has been established.

smgC32

I have used ATE blue/yellow, Motul RBF600 and Castrol SRF for years without any problem. MB does not approve these because they want to sell their fluid. I have no problem with their fluid and it is fine for street, but does not offer the same wet boiling point of the other fluids.

Your second paragraph does not draw a conclusion with a recommendation as to what interval you are proposing.

"but is not the reason brake fluid should be changed every two years. It is copper absorbtion that is a greater problem. Most workshops cannot measure the level, so a conservative time interval has been established"

Could you carry your logic further?

spr

Motul 600 is the best bang for the buck and closest to SRF wet and dry boiling point. The comment about the SRF soaking up moisture more is complete BS however. SRF is more hydroscopic and in fact will attract moisture less. I ran in on my 996 and it was superior to all of the aforementioned fluids. It has the highest dry and wet boiling points, so even if it does get some moisture as all fluids will, it will still outperform.

Fifth Ring

Any brake fluid that doesn't boil is as good as any other brake fluid that doesn't boil! I'm one day into my HPDE and the brakes are real good (considering the job they have to do!).

I'll report more later. Let's just say that there are some S4 and Evo owners mumbling about an old guy in a Benz.

smgC32

Sorry. I disagree. But I could stand corrected as I don't have the numbers off hand. SRF's wet boiling point is worse than RBF600 dry. SRF will deteriorate much more rapidly than other "street" fluids. Those serious racers that use SRF bleed their brakes after each race and therefore freshen up their fluid and their boiling thresholds. Two cars sitting on the street for six months without driving, then going to the race track. Which one will out perform the other? The RBF600. SRF cannot sit for long periods of time, or for that matter be used in normal interval changes of two years for street cars. Atmospheric conditions deteriorate the fluid more quickly. I have asked many racers and technicians this exact question over the years and have always gotten the same answer as I explained above. If you want the best fluid for a given day, use the SRF. If you don't plan on changing your fluid after several hours of extreme operation, then buy something else. I don't think anyone driving a C32/55 will notice any difference between fluids unless Hans Stuck is driving your car, and the SRF is truely four times the cost per liter. Most owners will be more than happy just utilizing the stock MB fluid which is about the same price as RBF600. Just my two cents.

spr

Your wrong srf has the highest wet and dry boiling and is higher than 600. Do your research. Further everything you state is hearsay and your pure conjecture. I speak from first hand knowledge on and off the track with my Porsche. I dont' know why I even bother and try to be helpful here sometimes.

Moviela

Sure. Mercedes has established the two year interval for changing brake fluid because the anti-oxidants in the fluid become depleted and allow copper in the fittings and brake lines to enter the fluid. The copper then pits the steel. Rather than have the workshop measure the copper in the fluid, they just set a time interval that assures continued safe operation of street cars. For more reading:

http://www.acustrip.com/brake_fluid_testing.pdf

At Mercedes approval of service parts is not reviewed by the sales department. It is the bailiwick of engineering alone. Mercedes uses advanced systems that require different fluids, oil, anti-freeze, transmission, & brake fluid, than used by other car makers. The much smaller numbers of Mercedes cars leads to mass markerters not being interested stocking slow moving consumables.

I agree with spr that Castrol SRF is excellent in a 996. Either that or ATE blue on race day. I would not put it in a daily driver. It is too expensive and no benifit comes from it.

smgC32

You didn't read my text correctly. What I said is that I believe RBF600 DRY boiling point is higher than SRF WET boiling point. I don't have time to research SRF numbers right now. Do you have them on your can? RBF600 fluid has a dry boiling point of 594 degrees and a wet boiling point of 421. Therefore my conclusion would be than SRF's wet boiling point is under 594 degrees. I also have first hand knowledge with SRF in my race car for years, and it got stale after a few months, but chose rather not only to rely on my own experience, but to give additional reference from racers and technicians I respect, including brake company representatives.

I am not trying to be difficult, buy challenge the topic and statements made herein, as you are, as to the merits of one fluid over the other. It is only with these type of debates that we gain further understanding and can make our own decisions. I have done this with countless topics regarding the C32 over the last four years and think I have contributed tremendously to the benefit of all who own our cars.

smgC32

Moviela, thanks for posting that article link. Interesting reading and it addresses issues affective longevity of the brake system. I now see where you point is made. However, I was not addressing system longevity, but extreme condtion track performance as Fifth Ring started this thread about going racing. Did you ever find out what the fluid leak was?

Castrol SRF has a DRY boiling point of 590 degrees and a WET boiling point of 518.

spr states "SRF is more hydroscopic and in fact will attract moisture less". I believe this statement is incorrect. SRF is LESS hygroscopic and will attract less moisture through rubber lines and other areas not completely sealed. This hygroscopic effect is different and does not address the moisture that developes in the system from brake fluid boiling, which is what we are concerned with when racing. And I have boiled my fluid on a regular basis at track days.

OPM

First of all, dry boiling point is irrelevant. It’s dry only while it is still in the bottle. You always want to compare wet to wet. Second, just because one has a higher wet boiling point does not mean it’s the best fluid. There are many factors that contribute to brake fluid performance. Look at it another way – lets say the fluid in your car reaches a maximum temperature of 320 degrees. Would you really care if one fluid boils at 540 and another at 520?

Castrol SRF is great, but only for a racecar that is being used year-round and is bleed religiously. If the fluid allowed to seat in the system for a few months it begins to eat all rubber seals. I used to run it in the S4, but then I got sick of dealing with it. I still have a few un-open bottles left. If you want, I’ll sell them to you cheap.

IMHO Motul RBF600 is a great choice. Unless you are boiling your fluid, I’d stay away from SRF. It is just too hardcore for most members of this board. And if you are boiling your fluid, you are probably melting your pads too. So I would start with learning a better braking technique. If that does not solve the problem add cooling ducts.

coin

How many quartz do you add back after doing the brake fluid flush?

Fifth Ring

It doesn't actually work like that. You bleed fluid from the calipers, and gradually keep adding to the fill bottle. I used about a liter to flush the C32, and I was probably overdoing it.

dsC32

Since I have seen so many people who change their own brake fluid have air in the lines when they get to the track, I have it flushed by the dealer. Most clubs require fresh fluid within 90-120 days of the event. Cost at dealer is right at $100 for fluid and labor. Allows me to get the dealer to go over the car and do the tech sheet, at no cost.

coin

1 L = 1.057 qz

Sounds good to me, I am trying to estimate how many quartz should I buy from the dealership. Thanks!

OPM

Guys you seem to be mixing terminology. Bleeding and flushing are two different things. Bleeding is what Fifth described. You remove a bit of fluid from calipers and brake lines. The goal is to remove air bubbles, excess moisture and overheated old fluid. Half a liter should be enough. I use Motive Power Bleeder. It works really well. Flushing is a process of replacing one fluid with another. For example, Castrol SRF does not like to coexist with other fluids. So to use it you would have to flush the whole system. Unfortunately, flushing ABS modules is a computerized process. So I let my mechanic take care of flushing. In S4 it took about 2 liters to flush brakes.

Fifth Ring

Flushing is just bleeding until the new fluid replaces the old. Same process, just more of it. And I've got it on good authority that the process for flushing the ABS units is probably not crucial. The amount of fluid in the ABS system is minimal.

Maybe I've had bad experiences, but I find that I screw things up a lot less than the dealers do -- and I know the quality of my work.