SL/R230: changing abc fluids
Thread Starter
Junior Member
Joined: Jan 2017
Posts: 40
Likes: 1
2007 sl 55 amg 2007 cls
changing abc fluids
2 years ago I had the fluids changed. Still wasn't sure it was all removed every year I drain the reservoir tank and refill it. That way i am constantly mixing in new fluids. good or bad idea thanks
Senior Member
Joined: Feb 2003
Posts: 443
Likes: 118
'03 S55 (79K miles)
Good
Changing ABC fluid (Pentosin CHF-11S) is always good, regardless of how you do it. Sucking out the reservoir fluid with a turkey baster or mighty vac and refilling with fresh fluid is a good practice.
The more you can get pumped out through the recirculated section near the pump, the better.
With engine off, removed the filter attached to the reservoir return pipe and extend the pipe to a catch bucket. Get some fresh bottles of fluid ready. Turn on the car and let the pump dump the old fluid that comes out of that hose into the bucket, while pouring fresh fluid into the reservoir, while a helper cycles the car’s up and down buttons. You will gradually see the dumped fluid becoming clearer green color as the fresh fluid recirculates. Then turn off the car and reassemble the filter and check levels. It is fairly safe to do this because this is a low pressure return line when the car is running. See several YTube videos.
But that doesn’t remove old fluid stuck out at the branches of piping to each wheel, or their accumulators, or at the shocks, or even at valve blocks. Those are under extremely high pressures when the car is running, so you cannot safely use the pump to help you for those.
For those sections, you can turn off the engine and disconnect each tube at the valve blocks and find a way to push fluid through til it flows out of the bleed nipples at each wheel well. Alternatively, without disconnecting any tubes at the valve blocks, I have had the car up on jacks with the 4 wheels hanging, slowly raised each wheel with a floor jack while cracking open its corresponding bleed nipple to bleed out the old fluid. Close the nipple and did the next one.
That makes room for a little fresh fluid. Not worth the effort unless you are also swapping out pipes and valve block and accumulators.
The more you can get pumped out through the recirculated section near the pump, the better.
With engine off, removed the filter attached to the reservoir return pipe and extend the pipe to a catch bucket. Get some fresh bottles of fluid ready. Turn on the car and let the pump dump the old fluid that comes out of that hose into the bucket, while pouring fresh fluid into the reservoir, while a helper cycles the car’s up and down buttons. You will gradually see the dumped fluid becoming clearer green color as the fresh fluid recirculates. Then turn off the car and reassemble the filter and check levels. It is fairly safe to do this because this is a low pressure return line when the car is running. See several YTube videos.
But that doesn’t remove old fluid stuck out at the branches of piping to each wheel, or their accumulators, or at the shocks, or even at valve blocks. Those are under extremely high pressures when the car is running, so you cannot safely use the pump to help you for those.
For those sections, you can turn off the engine and disconnect each tube at the valve blocks and find a way to push fluid through til it flows out of the bleed nipples at each wheel well. Alternatively, without disconnecting any tubes at the valve blocks, I have had the car up on jacks with the 4 wheels hanging, slowly raised each wheel with a floor jack while cracking open its corresponding bleed nipple to bleed out the old fluid. Close the nipple and did the next one.
That makes room for a little fresh fluid. Not worth the effort unless you are also swapping out pipes and valve block and accumulators.
Senior Member
Joined: Nov 2008
Posts: 324
Likes: 37
From: Wichita
Plays With Cars
I just did this last weekend using the drain into a bucket method. To drain the shocks I am fortunate enough to have a four post lift, so I just opened the drain valves at each corner and let the weight of the car force the fluid out. Worked great!
