Thread: ABS Module - Need your Thoughts

Steve,
I have studied the WSM fluid flow diagram in the modulator and am completely satisifed that running the ABS pump will circulate fliud through all passages. This is not the case if bleeding is achieved by pressing the brake pedal or via a pressurised feed from the top of the reservoir. Running the pump draws fluid through passages that do not get bled by conventional methods.

Originally Posted by Graeme

I found and fixed my D2's ABS modulator fault this afternoon. The post for the pins for the shuttle valve switch wire sockets would loose contact on 1 wire with the main harness socket if the post moved a little, suggesting faulty contact at the circuit board. I dug out the sealant directly behind the base of the post and resoldered the pins. After reassembly and checking that it was now fixed, I refilled the hole with new sealant and refitted the modulator, bled the brakes then gave the modulator a rigourous ABS and TC workout.

Resoldering can be done without disconnecting any pipes or removing the shuttle valve switches, but by only removing the modulator from its mounts enough to get access to the sealant below the front mounting stud, although disconnecting the brake lines to the wheels may give better access. It would be very worthwhile for anyone who has intermittent (or permanent) open circuit on the shuttle valve switch circuit to resolder these joints and see if that fixes their problem.

Pics of the resoldered joints:

Graeme,

Can you elaborate on what side of the ABS modulator you removed to expose the valve switch that needs soldering? Or can you take another picture further out to understand what part of the modulator it is?

Can see the two switch holes that the switch plugs into, just trying to work out where the two points are that need soldering.

I have a spare modulator on the bench at home and will do this ontop of the switch replacement before I put it in.

Thankyou.
JB

Ditto to JB's comment above - I would be interested in giving this a go before I send mine off to the UK for refurbishment.

But it is unclear to me what to pull apart to get access to the pins needing soldering.

Thanks
Keith

Just done this on a friends D2 yesterday, symptoms were shuttle valve switch on nanocom, switch was replaced but only fixed it for a few months, 3 amigos returned in avengance lol.......I removed the ABS modulator and split it down on the bench

after testing the pins at the socket I had an "open" circuit on the other end, where the 2 pins go into the shuttle valve switch. Its encased in plastic, but a hot knife as posted in the PDF file a while back works a treat, got access to the pins re soldered and so far so good.

pins 6 and 9 will test for continuity to the plug as well

Went out in the vehicle yesterday off road in the mud, vehicle has no CDL but got loads of ABS TC and HDC action and the 3 little buggers are still no where to be seen !!

a few piccys if it helps anyone for ref of whats what...

heres the unit "split" in half....



Heres the front of the "split" half showing the 2 pins where the shuttle valve switch connects to the main body. This is out of the "repair kit" Land Rover do containing the split half and the shuttle valve switches. I bought this kit incase "one day" mine goes wrong, but may never need it now lol



And apologies for the blurry piccy, but you should be able to make out the bottom of the 2 pins and see where I removed the plastic to access them for re-soldering, like in the PDF posted earlier in this topic.





Interesting to see the other end failed "open" on the post above, will keep that in mind if the fault returns or for the next one.

Urban, looks like Graeme has actually soldered the opposite side of the pins, eg if you note his picture, there is exterior dirt etc around the plate on the side he has soldered. If you look furtherthe part in which you have soldered on yours in on the opposite side of Graeme's pic.

Are there two different sections to solder? My perception is where Graeme has soldered is where the two pins plug in for the shuttle valve switch, obviously though I must be wrong.

I am really keen to try this so want to get the process right, if anyone is keen may be worth posting a tutorial then we can put it up in the "Good Oil", merley a suggestion though.

Sorry to be pushing further specific's, this is not something that I am knowledgable in however, all these posts are extremely helpful and appreciated.

Yes your right he has.

The Black rod is where the "body casting" containing the rod with the pins on the end is where the shuttle valve switch actually plugs in. This is where my "open" circuit was, at the other end of the rod, is where its soldered to the "board" inside the ali casting, this is where Graeme had his problem.

Its the same piece. It would depend on where you fault actually is. Graemes job is the first one I have seen done on that side / end of the rod. My outer pin was loose in the socket which when wobbled would break the continuity, so thats why I dug away at it to get to where the pins are physically soldered to the black rod.

Heres a couple more piccys which I hope will help..

This is one half of the unit, its where its actually plugged into the car, the pump is on the other half.



This is the famous shuttle valve switch.... the "cheap" bit. notice the 2 pin plug in the middle.



and thats where the shuttle valve switch is actually plugged into the ABS unit, it goes "through" the body of the other half, its very self explanitory when you dis-assemble it. One of the 2 pins you see on the end of the black rod is where my issue was.



Heres where I soldered v where Graeme soldered on the SAME part. I just resoldered the pins into the rod, and Graeme re-soldered the rod back to the internal board.



Hope that helps a bit more.

Hi All I thought I would continue on the back of this thread as there is a wealth of info that I keep referring to, so maybe worth looking at going on the good oil under the three amigo's threads Pedro?

Anyway I finally got the opportunity to do some work on the ABS modulator. Firstly replaced the switch on the modulator in my D2. No Luck...... Tested the switch I removed and it was also registering fine on the Ohms meter.

Next step pull apart my spare modulator make the changes as per the threads above, then swap over modulators on the car.

Not good news. Firstly the spring on the left hand side is sprung off a plastic rod coming out of the unit. The plastic rod has snapped off. Secondly the second picture the plastic prong that comes out with two small pins only has one pin sticking out and connected. The second pin is sitting in the opposite side of the unit, which highlights the soldering that Graeme undertook in the previous post.

I have rendered the unit beyond my ability to repair, as it looks significantly more damaged than the other units that have been posted previously, particularly with the plastic rod holding one of the tensioned springs broken.

The upside is I am heading over to the UK second week of Feb so my plan I think will be to take the spare unit over and swap it with a reconditioned unit from:

Land Rover Discovery ABS Pump/Module ECU WABCO - eBay, Land Rover, Car Parts, Vehicle Parts Accessories. (end time 23-Jan-10 00:15:33 AEDST)

I will have them send the unit to me in the UK, when I get over send them the unit I have locally. Currently with the exchange rate being the best it has been in years (56c) the reco unit will cost me approx $430. Then cost of someone to fit it when I get back.

A bit of a shame really as I was looking forward to having a crack at repairing it myself, however as stated it's beyond my skill base which is limited.

Anyway hope the additional info helps on what we are all seeing when pulling these units apart.
Cheers
JB