Mercedes-Benz Forum banner

1 - 20 of 40 Posts

·
Registered
Joined
·
239 Posts
Discussion Starter #1
I have a 2003 SL 500 with 30,000 miles.

I need an oil change so while it's at the dealer I thought I would have the hydraulic fluid changed. I called the dealer for a price and the dealer said they would do it but, it's not necessary. They said there is no shelf life and it's a sealed system. Dirt can't get in.

Now I'm not sure what to do. I've read on here how important it is to change it and Mercedes is telling me not to. Wouldn't they want the money?

Any advise?
 

·
Registered
Joined
·
338 Posts
Doesn't MB also like to sell parts????? The hydraulic fluid is hygroscopic, thus the water in the system can cause rust to develop on the steel in the system (pump for example). The same thing happens in the brake fluid system, where they fluid is hygroscopic and they DO recommend changing that every 3 years.

A fluid change costs about $250 for a DIY, or maybe $500 at the dealer. Replacing a pump etc. would be well over $2K, and with other parts, can run another 2-5K.

It's your choice, of course. For me - I purged and replaced my fluid within a few months after buying the car with 45K miles on it and 11 years of usage.
 

·
Registered
Joined
·
479 Posts
as above..........mercedes for the longest time also said never change the transmission fluid..........they are in the business of selling new cars.....

just change it........
 

·
Registered
Joined
·
239 Posts
Discussion Starter #4
I'm not going to change it. After a lot of research I've decided that changing the fluid can't hurt, it cost a lot of money and might not help. To do it correctly, it cost about $900.00. The pump could still fail and then I'm out the $900.00 plus doing it again.

I talked to three Mercedes dealers that said not to mess with it and two independent shops that said not to mess with it.

If the pump fails, I'll post and tell you the milage.
 

·
Registered
Joined
·
239 Posts
Discussion Starter #5
as above..........mercedes for the longest time also said never change the transmission fluid..........they are in the business of selling new cars.....

just change it........
I traded in my last to E class Mercedes with about 125,000 miles. Never did anything to the trans.

Really, the only maintenance I did to those two cars was break pads, engine oil and spark plugs. Changing the plugs didn't change the way the car performed at all. I could have let that one go.
 

·
Registered
Joined
·
79 Posts
You are welcomed to do what you want to

I'm not going to change it. After a lot of research I've decided that changing the fluid can't hurt, it cost a lot of money and might not help. To do it correctly, it cost about $900.00. The pump could still fail and then I'm out the $900.00 plus doing it again.

I talked to three Mercedes dealers that said not to mess with it and two independent shops that said not to mess with it.

If the pump fails, I'll post and tell you the milage.
As for me, it makes sense that the ABC system needs to run clean. And the fluid does get dark, if not maintained. If it is a sealed systems and it cannot get dirty, then what makes the fluid dark? Do you think the system can condense? I believe those that say if you keep the system clean, water free, and maintained, it will last the life of the car. Sure you might replace struts or accumulators here and there. But cleanliness is your ABC systems friend. Your pump and valves will love you. Of course your dealer won't be too happy to lose your business.

I did the flush myself with my wife helping me. Cost about $160 for 8L of Pentosin CHF11S. Hardest part was bleeding the struts. But if you don't want to do that, you'll get 90% of the fluid out with a standard flush and poor mans rodeo. My wife really enjoyed doing that. She felt like a low rider.
 

·
Registered
Joined
·
199 Posts
I think MB is giving you a theoretical answer...not the practical one. Yes the system is sealed. But all moving parts within the system generate friction and shed debris at the microscopic level into the fluid as they do their job. That is what is turning the fluid black.

This gunk starts to accumulate on surfaces within the system, and it especially loves to gum up the valve blocks. Not keeping the fluid clean will only mean the infamous corner sagging issues will come visit you sooner rather than later. More importantly...the rate of wear within the system accelerates the darker the fluid gets. This extra gunk results in more friction, generating even more gunk, creating even more friction, and so forth.

Paying a few hundred dollars now and every few years may very well save you multiple $2K+ repair bills later on.

My 2-cents...for what it is worth.
 

·
Registered
Joined
·
79 Posts
To do it correctly, it cost about $900.00. The pump could still fail and then I'm out the $900.00 plus doing it again.
Maybe you have done a lot of research. But might want to research the price of the fluid change. Go to a few specialty independent shops and ask their prices. Shop around. Dealers may well charge $900 for the fluid change. But they also charge $50/liter for the fluid that can be bought for $20/L.

While doing the job yourself is most simple and cheapest, I would bet you can find a good independent shop that will do it correctly for less than $400.

Or if you want to do it yourself, for $900 you could buy the SDS plus the computer, and the fluid, filter, a jack, and jack stands, and a set of wrenches for bleeding the struts, and have money left over for a few beers afterward. in four hours you'll be done. And next time (20,000 miles later) it will only cost you $200 for the fluid and filter. And beer. Because you have all the rest of what you need.

And you'll have a very happy car.
 

·
Registered
Joined
·
338 Posts
B15M,

Those of us who have chosen to get and keep our ABC systems as clean and fresh as reasonable wish you great success in your 'economical' approach to driving/servicing an automobile that was very expensive when new and whose dealers have very expensive parts when repairs are required.

In my 60+ years of buying and driving automobiles, I've concluded that good maintenance is more cost effective than repairs.

Best wishes and Good Luck!!
 

·
Registered
Joined
·
79 Posts
I'm not going to change it. After a lot of research I've decided that changing the fluid can't hurt, it cost a lot of money and might not help. To do it correctly, it cost about $900.00. The pump could still fail and then I'm out the $900.00 plus doing it again.

I talked to three Mercedes dealers that said not to mess with it and two independent shops that said not to mess with it.

If the pump fails, I'll post and tell you the milage.
You might want to consider....the antithesis of your logic...If you don't change your fluid, your pump WILL assuredly fail. If you do change and maintain you fluid, your pump likely WILL NOT fail.

In my case if the chances are 50/50, I'll lose 97% of the time. So to keep the 50/50 probability, someone out there has to WIN 97% of the time. Maybe that person is you?:smile
 

·
Registered
Joined
·
239 Posts
Discussion Starter #11
You might want to consider....the antithesis of your logic...If you don't change your fluid, your pump WILL assuredly fail. If you do change and maintain you fluid, your pump likely WILL NOT fail.

In my case if the chances are 50/50, I'll lose 97% of the time. So to keep the 50/50 probability, someone out there has to WIN 97% of the time. Maybe that person is you?:smile
I'm not sure that this is true. The pump might fail. You guys are giving me a lot of doubt about my decision.
 

·
Registered
Joined
·
338 Posts
To my 'old and simple mind', if the fluid has abrasives (minute small pieces of rust) as it is likely to have with old dark or even black ABC fluid, it is much more likely to wear the pump than is clean well filtered new green fluid.

I guess I'd say the same about the engine oil - bearings are more likely to wear with oil that has been there for 40,000 miles (about 1,200 hours and 6-10 years) than it is with oil that has been there less than 10,000 miles (about 350 hours and one year). Same with auto trans fluid, supercharger oil, differential oil, etc. etc. New is usually less abrasive than really old/used/dirty fluid.

Just my 'old school' beliefs.
 

·
Registered
Joined
·
9 Posts
Hydraulic oil change

Changed my very dirty oil a while ago. It's a breeze and will do it again without hesitation. Used a turkey baster to remove the oil from the pump. Cleaned the little divot out at the bottom of the container. Removed the return line and added more plastic tube and drained to a pail on the floor. Topped up the pump with fresh oil. Started the car and let it pump into the pail. Being careful not to let the levels in the pump drop and starve the pump(very bad news). Cycled the car height continuously (second person helps)and added fluid until expelled fluid ran clean. Shut off car and reconnect hose. Cycle and drive and recheck levels to ensure happy motoring. :grin
 

·
Registered
Joined
·
404 Posts
The new replacement filters for the ABC system are considerably more restrictive than the old ones - and they're measured in microns. I would think that such a change in the filter requirement via Benz would only happen out of necessity. This ABC system obviously does not deal well with contamination and it appears to contaminate itself over time and use. The fluid simply has to be replaced every 2 or 3 years with use - or not, suit yourself.

After watching the C3 star machine do a rodeo, the 'poor man's rodeo' doesn't compare as an assist in flushing the fluid, but it's better than nothing.

kev - A 'poor man's rodeo' simply involves manually raising and lowering the vehicle with the height adjust control button while the fluid is being drained and replaced into the reservoir at the same time. I think there's a youtube for it.
 

·
Registered
Joined
·
239 Posts
Discussion Starter #17
I had the oil changed at the dealer the other day on my E350. While there, I asked about the hydraulic change in the SL. I talked to a guy that's been there for a long time. He told me not to change it. Mercedes reps words, not mine. "You could stir up more trouble than you could help." I said, "How about just changing the filter" He said, "I wouldn't"

So, I'm not touching it. The car has 30,000 on it. I'll trade it in around 70,000. We'll see if I make it.
 

·
Registered
Joined
·
1,606 Posts
B15M, so you are offloading problem on the next sucker. Knowingly too. This why these SLs depreciate that much, because people like you.

Please post your VIN # so the rest of us could avoid stumbling over your soon-to-be-expensive beater.
 

·
Registered
Joined
·
1,606 Posts
"You could stir up more trouble than you could help."
Edited to be nicer to B15M.

Your alternatives are:

a. Do nothing
b. Change the fluid.

Advantages of a: It is free.
Disadvantage of a: While problem normally don't appear before 80K, your car could be an outlier.

This choice can be boiled down to: I bet x, where x if cost of fluid change, that I won't experience ABC failure that would cost me 10x before I sell the car. I will let next owner pay 10x.

Advantages of b: On a 30K car you unlikely to uncover hidden damage that service rep is warning about. Fluid change is not going to damage your car, rep is only warning you about discovering ongoing damage.
Disadvantages: It isn't free. Procedure is not complicated, but tech can mess up since they don't perform these every day.

This choice can be boiled down to: I will preemptively address the problem by paying upfront fraction of costs, also increasing resale value of my car if sold to a knowledgeable purchaser.


So why do you have to change this "lifetime" fluid? Well, there is no such thing. While ABC system is sealed when the car rolls out of the factory, time, weather cycles, and use all compromise this process. Tires are also "sealed", yet you don't act surprised that you have to add air maintain tire pressure.

Seals deteriorate, allowing humidity in. This causes condensation and rust. Mostly attacks valve bodies. Changing fluid purges all accumulated water.

Internal moving parts experience wear and tear, this results in very fine particles free-floating in the fluid. This changes fluid properties and puts additional stress on the pump. Changing fluid and filter purges all accumulated junk.

The same also applies to your hydraulic fluid used to operate your power top. I would recommend you change them BOTH.

In closing - keep in mind that "lifetime" refers to the life of the factory warranty. The problems I described impact these cars at 6+ years old and 80K+ mileage. Often when they are on second or third owner.
 

·
Registered
Joined
·
479 Posts
B15M - as SinSL says that flluid should be changed - the whole filled for life mumbo jumbo is exactly the same as the 'ole tranny filled for life oil saga - if you asked merc reps back then they would say the same - no dont change it - we all know how that worked out.....

Any fluid - change - it is easy and great preventative maintenance......
 
1 - 20 of 40 Posts
Top