Thread: 3 Amigo's 'Option A+', the other end.

Hi,
I've had my Disco for around 4 months now, when I bought it it had 152,000ks on it. After about a month of trouble free motoring, thinking how wrong all the nay sayers were, the 3 amigos popped up, then went away for a while, they became increasingly regular visitors. Their appearance was totally random, coming on whilst driving down a smooth flat bit of road or after applying the brakes with no regular pattern.
I had Offtrack ( thanks Bro ) check the codes with nothing definitive being shown ( I cant remember the exact codes ).
I decided to attempt 'Option A' as this is the most cost effective and least intrusive 'fix' and the random nature of the fault suggested to me that the cause was likely to be a dry solder joint ( fingers crossed). I'd also be able to see if there were was any fluid leakage.
With my ipad in hand and the Landroverclubvi instructions loaded up I headed down to my barn to get into it.
I followed steps 19-30, avoiding disturbing the hydraulic lines, all the bolts came out fairly easily.
With the parts on the bench I checked the operation of the SVS, with a DMM, checked out OK with no signs of fluid leakage.
I then plugged the SVS into SVS circuit board and tested again with the DMM to see if the resistance was correct at pins 9 and 6., this is where the fault was detected, intermittent continuity, must be those pins need re soldering.
I went ahead and carefully removed the plastic to expose the circuit board, hmmm, the solder looked to be perfect with no detectable cracking around the pins, I re soldered them any way.
Tested them again with the DMM, still intermittent continuity but when the svs circuit board proboscis ( snout thing ) was flexed there would be continuity!

Arrg, I looked up the price of a second hand unit, contemplated that for a few moments, thought about the time it would take to get a replacement part, then thought about where the circuit board disappears into the modulator, there must be another soldered connection in there.
What was there to lose? So armed with a sharpish scalpel I dug into the soft potting on the outer face of the modulator where I thought the other solder join might be.
Aha, not far in I uncovered the joints, they had a covering of a clay coloured powder, some type of corrosion. Cleaned them up and re soldered those joint and tested the resistance again, all good, rock solid!
I re potted the area I'd cut out using some black Sikaflex, just happened to have some on hand.
Once reassembled in the car the repair is hard to see as it is hidden under the rubber mount.
I had not come across this part of 'option a' documented while I was looking for a solution to the 3 amigos. However on reading over the Falcon works web site since I did notice this clue that hadn't sunk in when I had originally read it.

" Find a very good explanation here, of how to repair or bypass the old part, noting that the solder joints at the other end of the SVS proboscis also fail ... and can also be repaired. "

So far I've driven over 400k's with out the 3 amigos,
cheers,
Steve.

Originally Posted by syncro

Hi,
I've had my Disco for around 4 months now, when I bought it it had 152,000ks on it. After about a month of trouble free motoring, thinking how wrong all the nay sayers were, the 3 amigos popped up, then went away for a while, they became increasingly regular visitors. Their appearance was totally random, coming on whilst driving down a smooth flat bit of road or after applying the brakes with no regular pattern.
I had Offtrack ( thanks Bro ) check the codes with nothing definitive being shown ( I cant remember the exact codes ).
I decided to attempt 'Option A' as this is the most cost effective and least intrusive 'fix' and the random nature of the fault suggested to me that the cause was likely to be a dry solder joint ( fingers crossed). I'd also be able to see if there were was any fluid leakage.
With my ipad in hand and the Landroverclubvi instructions loaded up I headed down to my barn to get into it.
I followed steps 19-30, avoiding disturbing the hydraulic lines, all the bolts came out fairly easily.
With the parts on the bench I checked the operation of the SVS, with a DMM, checked out OK with no signs of fluid leakage.
I then plugged the SVS into SVS circuit board and tested again with the DMM to see if the resistance was correct at pins 9 and 6., this is where the fault was detected, intermittent continuity, must be those pins need re soldering.
I went ahead and carefully removed the plastic to expose the circuit board, hmmm, the solder looked to be perfect with no detectable cracking around the pins, I re soldered them any way.
Tested them again with the DMM, still intermittent continuity but when the svs circuit board proboscis ( snout thing ) was flexed there would be continuity!

Arrg, I looked up the price of a second hand unit, contemplated that for a few moments, thought about the time it would take to get a replacement part, then thought about where the circuit board disappears into the modulator, there must be another soldered connection in there.
What was there to lose? So armed with a sharpish scalpel I dug into the soft potting on the outer face of the modulator where I thought the other solder join might be.
Aha, not far in I uncovered the joints, they had a covering of a clay coloured powder, some type of corrosion. Cleaned them up and re soldered those joint and tested the resistance again, all good, rock solid!
I re potted the area I'd cut out using some black Sikaflex, just happened to have some on hand.
Once reassembled in the car the repair is hard to see as it is hidden under the rubber mount.
I had not come across this part of 'option a' documented while I was looking for a solution to the 3 amigos. However on reading over the Falcon works web site since I did notice this clue that hadn't sunk in when I had originally read it.

" Find a very good explanation here, of how to repair or bypass the old part, noting that the solder joints at the other end of the SVS proboscis also fail ... and can also be repaired. "

So far I've driven over 400k's with out the 3 amigos,
cheers,
Steve.

I purchased a Nanocom in order to resolve the 3 Amigos, read the fault code "11-05 Shuttle valve switch electrical fail 011 times" and then got stuck into removing the brake modulator to undertake the fix as you posted.
Once the unit was out and on the work bench it was a WTF moment .............someone had already tried it!! :-)
As the unit was already out, I picked out the silicon and confirmed the soldering was fine, tested continuity between pins, etc.
Tested the two shuttle valve micro switches and the resistivity reading were within published acceptable ranges.
Removed the 8 valves and noted that the brake fluid in one valve galleries was lead grey in colour and looked as though it contained fine aluminum "dust" (for lack of a better word".
Cleaned it all out, re-assembled the modular, fitted it, cleared the existing SLAB faults (previously they wouldn't clear), primed the brake lines manually then via the Nanocom power bleed, then took the TD5 for a drive.
Drove along dirt roads, braking around corners, along straights, and undertook emergency stops on both dirt and asphalt. Previously the three Amigos would have appeared in these driving conditions.
Thus far, 1 day elapsed time, the three Amigos haven't returned and fingers crossed they wont.
I feel like a guy who has just won the lottery
Suspect the grey aluminum dust in the brake fluid didn't help and the investment in the Nanocom has been well worth while.