Replacing TD5 shuttle valve switch????

**Patchy** · 17th August 2015, 11:21 PM

Ok so I have a 2004 TD5 110 that has the not so famous 2 amigos that has progressivly gotten worse were now its on more than its off, plug the nano onto it and shows the shuttle valve electrical fault same same as what disco guys get

So thought id do same fix and try replace the shuttle valve switch under the pump not so easy as I found out tonight on a defender as a disco.

So to my question has anyone replaced this little plastic switch with ease and not had to remove the whole pump to access it or are us defender owners forced to struggle and make a small job big. If you've replaced it or know an easy way please walk me through im all eyes

Really hoping there is a simpler way but looking at the stupid place they levered it into im not holding my breath.

Cheers in advance Brian

**Pedro_The_Swift** · 18th August 2015, 06:21 AM

will option B work on Defenders anyone?

Tombie · 18th August 2015, 08:50 AM

Originally Posted by Pedro_The_Swift

will option B work on Defenders anyone?

Option B is a wiring connector bypass - it does not fix the shuttle valves if they are faulting.

The Option B fix takes the 2 contacts internally out of the circuit (which have been known to get high resistance or break from vibration). creating a direct link to the Shuttle valve switches themselves.

If the switches are failing - usually due to brake fluid leak down from the shuttle valve cartridges themselves, then replacing them is the only long term solution.

**CraigE** · 19th August 2015, 08:14 AM

They can be a PIA. I had mine out a while back to try the bypass, it did not work as the shuttle valve itself was cactus (no resistance or at least not to spec). I got a new shuttle valve a while back and was waiting for my new disc rotors to arrive before doing it all at once. Including caliper refurbishment. They have now arrived so will now begin when I have time.
I have been advised even with the new shuttle valve to do the bypass straight up.
Now it is not as simple in a Defender to replace in situ and to remove can be tricky, but can be done.
This is the way I did it.
1: Syringe out all brake fluid from reservoir (I used syringe and 18g needle).
2: I cracked the brake pipes on the WABCO unit and then syringed out unit. (next time I may just crack the bleed nipple at the caliper and pump out that way).
3: Unbolt WABCO unit, can require some patience and small hands.
4: Now comes the fun bit, if you want to remove you need to rotate until you find a position that it will clear the guard etc. If you have some small bolts or threaded caps fit these to the WABCO unit pipe inlets as will stop some spillage. Took me best part of 20 minutes, fluid residue leaking everywhere. As soon as removed gave a good degrease.
5: If you are not going to remove you can just rotate until the shuttle valve faces up and remove the shuttle valve.
6: If doing the bypass either use existing shuttle valve if ok or new one.
7: Refit and if doing the bypass connect up wires.
Cheers
CraigE

**CraigE** · 19th August 2015, 08:18 AM

Originally Posted by Pedro_The_Swift

will option B work on Defenders anyone?

Yes, but there is only scant information on them for the Defender. There are a couple of UK posts that have indicated it works fine.
While the Defender Shuttle valve is not listed and technically they appear to only sell the complete WABCO unit complete, that is in fact incorrect.
The Discovery Shuttle Valve is identical to the Defender one.
Not sure if it is an over site or LR just trying to rip off Defender drivers.
I have a pic somewhere on my personal computer where someone has done a variation of option B where they have tapped into the wiring and left the wire in place rather than cutting and running separately. May be the way to go.
Cheers
Craig

**Patchy** · 19th August 2015, 11:05 AM

Thanks Craig not exactly what I wanted to hear but was thinking I was going to have to remove the unit to get to the switch underneath was looking at if its possible to remove the inner guard to get under the valve. Give me the excuse I surpose to replace my brake lines I've been putting off.

when you do option B does the traction control still work as normal or does it just trick it so the lights dont show on the dash?

cheers Brian

Tombie · 19th August 2015, 11:54 AM

Patchy... Read my post....

Option B - does not fix anything but the broken connector issue.

Failed shuttle valve switches - are a separate issue.

To see if the connector pins are faulty a multimeter will let you know....
If it passes the connectivity test after replacing the shuttle valve switch assembly you don't need to do option B.

On the units I've repaired, Option B would have achieved nothing as the connections were solid, but the switches were outside their correct values.

**CraigE** · 19th August 2015, 06:03 PM

Hey Brian,
It is certainly not a difficult job, just a PIA to work out how to get out and getting it in the right position to come out. Having said that it does not have to completely come out to replace the shuttle valve, just rotate it in situ and replace. Just a bit messy and tight. Removing the inner guard would be overkill, though yes it did cross my mind.
As Tombie said option B is not a fix for a buggered shuttle valve itself it is about fixing or preventing a dry solder crack that causes the lights to come on when there is actually nothing wrong. It is an electrical fault. It is my understanding that the option B fix will not stop the ABS or Traction Control, on the contrary it will enable it to work as it should. Part of the issue is when the lights do come on ABS and Traction Control stop working, due to either a buggered shuttle valve switch or as for Option B a dry solder crack. The shuttle valves still work in the Option B scenario.
In my case the shuttle valves themselves were buggered, not giving correct resistance readings, so Option B will not fix this, a new shuttle valve is required ($86 I think mine cost). However if you are getting correct resistances at the micro switches Option B may work.
The next question once you have worked out what the issue is, is which way to go? Do you just replace the whole switch if the resistances are wrong or do you do option B as preventative maintenance? If the switches are in spec just do option B. The only issue is if you do option B the wiring can be need a bit of work to revert back to original if you change your mind and want to go back to original. As mine is set up for Option B anyway with the wires spliced and grounded I will probably go that way.
Cheers
Craig

Originally Posted by Patchy

Thanks Craig not exactly what I wanted to hear but was thinking I was going to have to remove the unit to get to the switch underneath was looking at if its possible to remove the inner guard to get under the valve. Give me the excuse I surpose to replace my brake lines I've been putting off.

when you do option B does the traction control still work as normal or does it just trick it so the lights dont show on the dash?

cheers Brian

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