SL55/63/65/R230 AMG: ABC hissing sound
09-28-2016, 02:41 PM
#1
Member
Thread Starter
ABC hissing sound
Hi all,
- From day one I've bought this SL, i always hear a hissing sound (air leak) from the front driver side near the tire. Everytime I raise/lower the car the sound stops for a couple of seconds and come back again. Tried to jack the car frlm front and open the abc reservoir and turn the steering couple of times. But that did not work.
- Also yesterday, the abc reservoir started to flow fluid, and over a bumpy road, the ABC drive carefully popped and disappeared. And I feel a vibration from the driver seat.
- I've changed the pulsation dampener before that problem occurs as a preventative maintenance.
From reading here, I guess i have to change front and rear accumlators. Should I change the return accumlator too ?
What about the hissing sound ?
Thanks in advance
- From day one I've bought this SL, i always hear a hissing sound (air leak) from the front driver side near the tire. Everytime I raise/lower the car the sound stops for a couple of seconds and come back again. Tried to jack the car frlm front and open the abc reservoir and turn the steering couple of times. But that did not work.
- Also yesterday, the abc reservoir started to flow fluid, and over a bumpy road, the ABC drive carefully popped and disappeared. And I feel a vibration from the driver seat.
- I've changed the pulsation dampener before that problem occurs as a preventative maintenance.
From reading here, I guess i have to change front and rear accumlators. Should I change the return accumlator too ?
What about the hissing sound ?
Thanks in advance
Last edited by mAMG; 09-28-2016 at 11:30 PM.
04-18-2017, 03:38 PM
#2
Member
Thread Starter
Any help ?
ABC Visit workshop appeared now in white/blue. It comes randomly, sometimes it shows up once you start the car and sometimes it goes when you restart.
Changed the Tandem pump, still the same problem.
Checked it through DAS it shows the travel plunger sensor is dedective .. ? Mechanic says its not, and he insists its the rear valve.
Done the Redo test, the rear is not smooth .. Doesnt raise/lower smoothly.
Any idea ?
ABC Visit workshop appeared now in white/blue. It comes randomly, sometimes it shows up once you start the car and sometimes it goes when you restart.
Changed the Tandem pump, still the same problem.
Checked it through DAS it shows the travel plunger sensor is dedective .. ? Mechanic says its not, and he insists its the rear valve.
Done the Redo test, the rear is not smooth .. Doesnt raise/lower smoothly.
Any idea ?
04-19-2017, 02:24 PM
#3
Super Member
on an 03 all 4 accumulators need replaced just due to age (they are merely rubber spheres with a nitrogen charge in them that degrade over time). That could fix the problem with the blue message, but possibly not. regardless you should do it as prevent maint to lower the stress on the hoses. the hissing sound is most likely a valve block that is bad and liquid is going past the orings in the locking valve causing noise. If you sit the car and let it idle for 10-30 min you might see a corner slowly rise or fall b/c of this. The noise is going away when you are raising/lowering b/c the locking valve is now open and letting fluid either in or out. In the valve block there are 2 valves for each strut. One locks and prevents any fluid from going in or out (this occurs when you are at a stop or parked the car) and the other tells fluid either to go into the strut or out of the strut (this valve is constantly acting when you are driving).
The other issue you might be having is that a hose is starting to weep and about to go causing pressure loss (if its not a problem now it most likely will be soon given the age of the vehicle). check the ends of your pressure hoses, especially the 2 that run under the radiator that go to each front strut as well as the one that goes from the tandem pump through the engine compartment and to the pressure regulator in the drivers wheel well. these 3 hoses are usually the first to go due to engine heat and you will see fluid weeping near the crimped ends or bubbles forming in the hose. in my 03 all 3 were about to go bad. I have an extra rebuilt one that goes from pump to pressure regulator that i'd sell. It has AN fittings in place of the crimped ends so the rubber hose parts can just be replaced in the future without having to remove the entire line. With that particular hose you also have to remove the AC compressor to get the hose in/out if you don't have removable flex hoses like what I did. To remove the old one simply cut the rubber parts and it will come out easy without the need for AC compressor removal. Then you can assemble the whole thing with the removable hose I made.
if its the rear valve block you have 3 choices
1) rebuild it
2) buy a rebuilt one
3) buy a new one, which is a slightly different design and also requires replacement of 2 ABC hoses as the hookups are different on the new design vs. the old (FYI the front block can be updated to the new without having to change hoses but not the back)
The other issue you might be having is that a hose is starting to weep and about to go causing pressure loss (if its not a problem now it most likely will be soon given the age of the vehicle). check the ends of your pressure hoses, especially the 2 that run under the radiator that go to each front strut as well as the one that goes from the tandem pump through the engine compartment and to the pressure regulator in the drivers wheel well. these 3 hoses are usually the first to go due to engine heat and you will see fluid weeping near the crimped ends or bubbles forming in the hose. in my 03 all 3 were about to go bad. I have an extra rebuilt one that goes from pump to pressure regulator that i'd sell. It has AN fittings in place of the crimped ends so the rubber hose parts can just be replaced in the future without having to remove the entire line. With that particular hose you also have to remove the AC compressor to get the hose in/out if you don't have removable flex hoses like what I did. To remove the old one simply cut the rubber parts and it will come out easy without the need for AC compressor removal. Then you can assemble the whole thing with the removable hose I made.
if its the rear valve block you have 3 choices
1) rebuild it
2) buy a rebuilt one
3) buy a new one, which is a slightly different design and also requires replacement of 2 ABC hoses as the hookups are different on the new design vs. the old (FYI the front block can be updated to the new without having to change hoses but not the back)
04-19-2017, 08:32 PM
#4
Member
Thread Starter
on an 03 all 4 accumulators need replaced just due to age (they are merely rubber spheres with a nitrogen charge in them that degrade over time). That could fix the problem with the blue message, but possibly not. regardless you should do it as prevent maint to lower the stress on the hoses. the hissing sound is most likely a valve block that is bad and liquid is going past the orings in the locking valve causing noise. If you sit the car and let it idle for 10-30 min you might see a corner slowly rise or fall b/c of this. The noise is going away when you are raising/lowering b/c the locking valve is now open and letting fluid either in or out. In the valve block there are 2 valves for each strut. One locks and prevents any fluid from going in or out (this occurs when you are at a stop or parked the car) and the other tells fluid either to go into the strut or out of the strut (this valve is constantly acting when you are driving).
The other issue you might be having is that a hose is starting to weep and about to go causing pressure loss (if its not a problem now it most likely will be soon given the age of the vehicle). check the ends of your pressure hoses, especially the 2 that run under the radiator that go to each front strut as well as the one that goes from the tandem pump through the engine compartment and to the pressure regulator in the drivers wheel well. these 3 hoses are usually the first to go due to engine heat and you will see fluid weeping near the crimped ends or bubbles forming in the hose. in my 03 all 3 were about to go bad. I have an extra rebuilt one that goes from pump to pressure regulator that i'd sell. It has AN fittings in place of the crimped ends so the rubber hose parts can just be replaced in the future without having to remove the entire line. With that particular hose you also have to remove the AC compressor to get the hose in/out if you don't have removable flex hoses like what I did. To remove the old one simply cut the rubber parts and it will come out easy without the need for AC compressor removal. Then you can assemble the whole thing with the removable hose I made.
if its the rear valve block you have 3 choices
1) rebuild it
2) buy a rebuilt one
3) buy a new one, which is a slightly different design and also requires replacement of 2 ABC hoses as the hookups are different on the new design vs. the old (FYI the front block can be updated to the new without having to change hoses but not the back)
The other issue you might be having is that a hose is starting to weep and about to go causing pressure loss (if its not a problem now it most likely will be soon given the age of the vehicle). check the ends of your pressure hoses, especially the 2 that run under the radiator that go to each front strut as well as the one that goes from the tandem pump through the engine compartment and to the pressure regulator in the drivers wheel well. these 3 hoses are usually the first to go due to engine heat and you will see fluid weeping near the crimped ends or bubbles forming in the hose. in my 03 all 3 were about to go bad. I have an extra rebuilt one that goes from pump to pressure regulator that i'd sell. It has AN fittings in place of the crimped ends so the rubber hose parts can just be replaced in the future without having to remove the entire line. With that particular hose you also have to remove the AC compressor to get the hose in/out if you don't have removable flex hoses like what I did. To remove the old one simply cut the rubber parts and it will come out easy without the need for AC compressor removal. Then you can assemble the whole thing with the removable hose I made.
if its the rear valve block you have 3 choices
1) rebuild it
2) buy a rebuilt one
3) buy a new one, which is a slightly different design and also requires replacement of 2 ABC hoses as the hookups are different on the new design vs. the old (FYI the front block can be updated to the new without having to change hoses but not the back)
It turned out to be the rear left sensor.
My car does raise from the right front as you said, although the mechanic did rebuild the front valve. So now i guess i need to change the valve to fix it and fix the hissing/air noise?
Lastly, there is a flutter sound like exhaust/headers leak from the front left, the mechanic said its the ABC hose at front left strut. I did change it (#A2309977082) , but the sound is still there. The sound appears under engine load (partial to half the throttle pedal .. ) ?!
11-03-2020, 06:51 AM
#5
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Join Date: Sep 2020
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SL55
Abc Hissing sound and raising slowly itself
on an 03 all 4 accumulators need replaced just due to age (they are merely rubber spheres with a nitrogen charge in them that degrade over time). That could fix the problem with the blue message, but possibly not. regardless you should do it as prevent maint to lower the stress on the hoses. the hissing sound is most likely a valve block that is bad and liquid is going past the orings in the locking valve causing noise. If you sit the car and let it idle for 10-30 min you might see a corner slowly rise or fall b/c of this. The noise is going away when you are raising/lowering b/c the locking valve is now open and letting fluid either in or out. In the valve block there are 2 valves for each strut. One locks and prevents any fluid from going in or out (this occurs when you are at a stop or parked the car) and the other tells fluid either to go into the strut or out of the strut (this valve is constantly acting when you are driving).
The other issue you might be having is that a hose is starting to weep and about to go causing pressure loss (if its not a problem now it most likely will be soon given the age of the vehicle). check the ends of your pressure hoses, especially the 2 that run under the radiator that go to each front strut as well as the one that goes from the tandem pump through the engine compartment and to the pressure regulator in the drivers wheel well. these 3 hoses are usually the first to go due to engine heat and you will see fluid weeping near the crimped ends or bubbles forming in the hose. in my 03 all 3 were about to go bad. I have an extra rebuilt one that goes from pump to pressure regulator that i'd sell. It has AN fittings in place of the crimped ends so the rubber hose parts can just be replaced in the future without having to remove the entire line. With that particular hose you also have to remove the AC compressor to get the hose in/out if you don't have removable flex hoses like what I did. To remove the old one simply cut the rubber parts and it will come out easy without the need for AC compressor removal. Then you can assemble the whole thing with the removable hose I made.
if its the rear valve block you have 3 choices
1) rebuild it
2) buy a rebuilt one
3) buy a new one, which is a slightly different design and also requires replacement of 2 ABC hoses as the hookups are different on the new design vs. the old (FYI the front block can be updated to the new without having to change hoses but not the back)
The other issue you might be having is that a hose is starting to weep and about to go causing pressure loss (if its not a problem now it most likely will be soon given the age of the vehicle). check the ends of your pressure hoses, especially the 2 that run under the radiator that go to each front strut as well as the one that goes from the tandem pump through the engine compartment and to the pressure regulator in the drivers wheel well. these 3 hoses are usually the first to go due to engine heat and you will see fluid weeping near the crimped ends or bubbles forming in the hose. in my 03 all 3 were about to go bad. I have an extra rebuilt one that goes from pump to pressure regulator that i'd sell. It has AN fittings in place of the crimped ends so the rubber hose parts can just be replaced in the future without having to remove the entire line. With that particular hose you also have to remove the AC compressor to get the hose in/out if you don't have removable flex hoses like what I did. To remove the old one simply cut the rubber parts and it will come out easy without the need for AC compressor removal. Then you can assemble the whole thing with the removable hose I made.
if its the rear valve block you have 3 choices
1) rebuild it
2) buy a rebuilt one
3) buy a new one, which is a slightly different design and also requires replacement of 2 ABC hoses as the hookups are different on the new design vs. the old (FYI the front block can be updated to the new without having to change hoses but not the back)
