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Let us revive this excellent thread.
I’ve gone through it several times and always find something new. Now I’m very much interested in how it works or to be more precise -
What happens when the on signal is sent to the pump, how it engages? Is there hydraulic or electromagnetic clutch in there?
No clutch, the pump is direct drive like any p/s pump. There is a PWM valve on the inlet side referred to as a restrictor valve or suction valve, it opens to allow fluid in, I believe it defaults to open position and closes as needed but I may be mistaken on that.
I'm mid rebuild on me ABC pump for a 2004 SL500. I have replaced the O rings but the actual failure lie in one of the HEX nuts. I've inquired at an MB dealership but can't get the part there. Does anyone know where these could be purchase or is anyone sitting on an old pump that they could part?
Well, the 2003 CL55 AMG has long been out of my possession but I wanted to give some thoughts about what I had to do to get the car running again. This is merely a DIY post of rebuilding the entire ABC system to factory conditions.
TLDR: Proceed to ABC delete and get yourself a worthy coil-over conversion kit. They are are cheaper, lighter, and a fast solution to get your ABC-problem car up and running sooner. You may need an ABC bypass module to get rid of the dash problem or find a way to unplug ABC fuses or sensor, I don't know the proper solution.
1. The pump rebuild is only a temporary band-aid to the entire solution. The ABC suspension system is great when it works, but it is horrible and expensive when it fails.
There are tons of o-rings and improper lubrication of the system will cause parts to grind leading to bits and pieces within the ABC system to one-day clog up a line.
2. The pump was rebuilt and it was in great condition but like the ABC service bulletin each part of the system should be inspected.
3. To ensure the entire ABC system functioned like it did here are some things I did:
- Every valve block was rebuilt, cleaned with gasoline/brake cleaner, o-rings replaced with nitrile based o-rings.
- Accumulators were all replaced
- Each strut was removed and replaced with remanufactured Arnott struts. The quality of the Arnott struts were great and I compared the struts to be identical to the original AMG struts I had at the time.
- CHS-11S Pentosin oil leaked everywhere but was basically flushed and bled at every strut where a nut can be loosened to release power-steering fluid.
4. The enemy of the reconditioned ABC system is air. Bleeding the system will first prime the system and you can do this by releasing a nut found near each strut..
- Despite bleeding, rebuilding pump, changing struts, rebuilding valve blocks, and accumulators the ABC service indicator on the dash still came up.
- What I think is that the ABC computer detects the pressure throughout the system especially at each strut and if the sensor does not receive acceptable data it throws the ABC service light.
- What I did: I let the car run until the oil was hot, I turned the steering wheel from left to right countless number of times. I used the hydraulic function to raise the car up and down countless times.
- Eventually, the ABC service light went away but intermittently flashed throughout the test drive on day 1.
- My thought is that again the computer is detecting the new pressures and I repeated the same steps of waiting for the oil to heat up, steer left to right, raise the car up-and-down.
- It should be obvious that the pulley also runs on the same engine belt and when the engine revs to high RPM it also spins the ABC pulley. I left the cap to the reservoir off and would gas the engine occasionally in hopes it would get rid of air in the system.
Conclusions:
- This last post is basically a DIY of replacing all the essential parts of the ABC system besides the ABC hoses.
- After completing the entire DIY the car was as smooth as the day I got the car and before all the ABC problems started. No ABC warning on DASH and no need to buy an ABC bypass module.
- The ABC system is difficult to maintain and anything can go wrong. I'm sure the life and reliability of the system also depends on driving styles and how often the filters and power steering pump oil are appropriately changed.
- Rebuilding the pump is only temporary and you need to also check the rest of the system. The boot for each of my struts were worn and I'm sure they were nearing the end of their life at 110k miles which is why I replaced them.
- Once you truly know the failures of the system and what it takes to get the ABC system to work, it simply isn't worth it. The suspension was fantastic throughout the time I've had the car but it was time to let it go. I've never driven a vehicle that turns so smoothly at the steering wheel.
- All in all, if you want to drive a beast with the ABC system I'd recommend ABC delete and converting to coil-overs with whatever modifications to improve the experience ex. sway bars.
Last edited by alvintran12; 12-24-2020 at 12:00 PM.
Reason: misspelling and a period
I seem to have an intermittent problem with my ABC service liked it comes and goes when I start the car. I noticed that it pulls to the right when the light is on but what’s interesting is when I have the car on an uneven surface it doesn’t seem to have a problem Error message goes away. It seems to always come on when I’m on level ground in my garage. Does anybody have any idea what could be causing this. What noticeable is when it’s on and I drive the card pulls to the right. When I’m on an uneven surface and I start the car the air message goes away in the message box and drives perfectly normal.
08-25-2019, 04:04 PM
