ABC Newbie

Johnte

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New SL Owner with ABC fault, if anyone could offer advice please..

Having searched the forum, I think I need to replace valve block seals ( car is sinking on drivers side when parked, but losing no fluid ) unless any other suggestions..

I've found lots of help and advice on dismantling the valve block, but can't find anything on removing it from the car, releasing pressure etc. Could anyone help please ?

I'm just a bit baffled why both front and rear both sink, would this still suggest valve block ?

Thanks in advance.
 

John Laidlaw

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So, sinking on drivers side both struts- front and rear?
What happens when you cycle the height? Does it raise back uniformly....
Warning on dash?
Craig on here has valve block seals but we need to establish it is the valve block....
Also how’s the fluid looking?
 
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Johnte

Johnte

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All struts and pump have been replaced over the last four or five years, ABC fluid and filter were changed at the last service.
I would say does raise uniformly when cycling heights.

Sorry forgot to mention.. I have Autologic report in the file that came with the car that states -

ABC:Active body control REAR RIGHT suspension strut moves although locking valve is closed.

Would that suggest valve block ?
 

alexanderfoti

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All signs point to valve blocks. They can have the seals replaced, speak to Craig on here.

Sometimes the valves get stuck and you have to then replace the valve body.
 

Craiglxviii

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Hiya...

If the strut is moving when the locking valve is closed then that points to the locking valve not cycling. This is, I'm sorry to say, Not Good News. The valve shuttles are not available separately and must be purchased as a complete valve block assembly as Alex has said. They are around £1k each (2 x "Standard Repair Units" for a 500- it helps to think of things this way...)

The Good News is that you CAN test the valve to see if its solenoid actuates by applying a 12V feed to it, once removed from the car.

I do have seal kits available, for £50 per axle. To rebuild the valve block you will need to build yourself a clean room space, most people use two plastic stacker boxes with lids, one for cleaning the block out (using Pentosin CHF.11S as a cleaning agent, and a toothbrush) and the other for reassembly. You may need more than two depending on how much gunk has built up- it's safer to throw away a dirty box and use another @ £1.50/ea than clean it out and risk missing a speck of gunk. You'll have to put the car on axle stands while you do this and ensure that the ABC lines have plastic end cars fitted covering the threads. Not a single speck of dirt can be allowed to enter or the whole thing's scrap.

If you want the seals please let me know as I have a really busy few weeks ahead. They're top quality with many satisfied customers on here (and a few others who don't know they have my seals in their cars too).
 
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Johnte

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Oh no.. I've gone and jumped in and ordered a seal kit off ebay - I'm sure you're going to tell me the quality is inferior, and I did pay more money !! But I didn't realise they were available on here.

The whole of the drivers side seems to sink, would the faulty rear locking valve cause this ?
 

alexanderfoti

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Oh no.. I've gone and jumped in and ordered a seal kit off ebay - I'm sure you're going to tell me the quality is inferior, and I did pay more money !! But I didn't realise they were available on here.

The whole of the drivers side seems to sink, would the faulty rear locking valve cause this ?

You must have leaking lock valves front and rear for one whole side to drop.

I think the seals on ebay are the wrong sizes and the wrong material, so whilst they work, they only do so for a short period of time. Craig will confirm.
 

Craiglxviii

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Craig, where do you get your seal kits from?

I source them direct from the aerospace industry Steve. This is an area I have some small experience in- when I needed my own, I looked at the quality standard for automotive hydraulic O-rings. Then after I picked myself up off the floor and stopped gibbering, shaking, crying and rocking back & forth a while, I went to my old contacts in aerospace and sourced proper stuff that won't self-immolate within 1000 cycles.
 

Craiglxviii

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You must have leaking lock valves front and rear for one whole side to drop.

I think the seals on ebay are the wrong sizes and the wrong material, so whilst they work, they only do so for a short period of time. Craig will confirm.
They're a false economy for sure. I bought a kit to have a look and, well, it's still in my toolbox. Actually, tell a lie it's under the stairs and my 14mth old is using it as a toy at the moment. They are the right sizes- although I have doubts about the compressibility of the material- but the material itself is very much not correct. Depending on the colour, it's either not stable in light oil, not stable above maintained 60 C, not stable below maintained 5 C, and/ or not stable under movement.
 

Steve@Avantgarde

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I source them direct from the aerospace industry Steve. This is an area I have some small experience in- when I needed my own, I looked at the quality standard for automotive hydraulic O-rings. Then after I picked myself up off the floor and stopped gibbering, shaking, crying and rocking back & forth a while, I went to my old contacts in aerospace and sourced proper stuff that won't self-immolate within 1000 cycles.

I could be interested in a set for my SL55AMG.
 

John Laidlaw

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Sorry, off line for a bit but Alex and Craig are looking after you much better than I could now...

Regard the valve block seal kits, my local indy bought a set off ebay to do another SL (not mine!) and gave up eventually on the valve block rebuild...ended up with a recon valve block I believe. So not only wrong sizes and material but didn’t seal at all!

Guys, just wondering on accumulators?
 

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What are you wondering about them? :)
Would they cause one side to dip, e.g. return fluid- or is it purely the valve block seal (or lack of) that isn’t giving sufficient pressure? :) I wonder on loads of stuff Alex, not often from a completely knowledgeable position!! :)
 

alexanderfoti

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Would they cause one side to dip, e.g. return fluid- or is it purely the valve block seal (or lack of) that isn’t giving sufficient pressure? :) I wonder on loads of stuff Alex, not often from a completely knowledgeable position!! :)

Ah I see!

Failed accumulators cause a very brief "ABC - Visit workshop" in red when hitting bumps and undulations in the road. They are there to keep a continuous supply of pressure to the struts for instantaneous demands when the pump cannot cope.

Failed return accumulators will cause ruptured pipes, hose leaks etc.
 

Craiglxviii

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Would they cause one side to dip, e.g. return fluid- or is it purely the valve block seal (or lack of) that isn’t giving sufficient pressure? :) I wonder on loads of stuff Alex, not often from a completely knowledgeable position!! :)

They affect one axle not one side/ corner, and they don't quite work in the way you suggest- they're an immediate fluid reserve for management of shock loads. If there's an individual wheel sinking with engine off then it has to be the lock valves.
 

Craiglxviii

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