abs sensors no a circlip

[spudd]

bugger me bought 2 front abs sensors as abs light always coming on.they sheared off trying to remove. paid local mehanic to remove hubs and drill out old sensors. £40 not bad saved gettin me hands dirty.he did drivers side when he removed cap on n/s fixed hub he found the clip that holds the shaft in was missing.so the shaft was drifting in and out upto 20mm+.so sensor ring was drifting away from sensor and causing abs to cut in.so i spent £245 on new sensors plus the mechanics £40 for the sake of a poxy circlip:lol.
have to laugh or i cry.

 

[macabethiel]

Okay its hindsight but doing a resistance check is always worthwhile before you start spending serious money on new sensors.

I bought a 4 WD Estate car some years ago and when I bought it all four sensors were new and yet the ABS would trip in at the last minute when you were stopping. Turned out to be rust on the reluctor rings sending a false signal. Wire brushed the ring and improved it by about 80%. Unfortunately the rings were part of the front driveshafts and at over £900 each I lived with it till I sold it 3 years later.

 

[spudd]

had a resistance test done all seemed ok.on the bright side it was the wifes money and i got 2 shiny new sensors.

 

[macabethiel]

hinsight

had a resistance test done all seemed ok.on the bright side it was the wifes money and i got 2 shiny new sensors.

So if the resistance test was okay why go on to replace them its pointless like replacing a bulb that works when tested and not looking at the switch, wiring etc?

 

[spudd]

because i assumed sensors were knackered . if i disconnected the sensor reconnect sometimes it would stay off making me think it was a sensor.obviously when the resistance test took place the drive shaft would have been in the right place and not affecting sensor so i thought intermittent sensor fault.lets be honest how many people would have said hold on before i buy a new sensor i must check drive shaft circlip.

 

[glen]

You might have tried this worked for me, you might have seen the missing circlip

REPAIRING SENSORS

your old sensor can easily be repaired the sensor very rarely goes wrong its the wiring that connects it that breaks down and can be replaced by a competent DIY person or an auto electrician with very little kit needed you need a multimeter a soldering iron and solder some heat shrink (resin sealing is best) and some cable.

1. Too find the faulty sensor jack up and support the front of the vehicle on axel stands and remove the front wheels.

2. disconnect both front sensors from behind the rubber splash guard (follow the cable to the chassis) and unbolt the brackets that hold it to the suspension (do not remove the sensors from the hub as they will be rusted solid and you will damage them getting them out )

3. switch on your multi meter and set it to ohms connect the two leads to the two connectors inside the plug of the sensor lead (it doesn't mater which way round ) you should get a reading (1.1ohms to 1.3 ohms off the top of my head) get some body to hold the plug and multimeter leads while you wiggle the cable if the reading on the multimeter changes that is the faulty sensor you may have to bend the cable quite tight to find the broken wire its usually in the last bit of protective sleving (rubber hose ) before the sensor.

when you find the faulty one lay it on a piece of cardboard and mark the positions of the sleving and the brackets as you will need to remove these and put them back on later you can prixe the metal brackets off with a screw driver and after cutting the plug off the end of the sensor lead (leave a bit of cable to reconnect it) you can slide the sleving off with a bit of wd40

cut open the protective casing of the twin core cable and strip it back revealing the two cables work your way to the sensor you will probably see the broken wire just after the break cut the cable and find a length of new cable of the same size (this is important) there are plenty of car electrical shops that will help you solder the new cable onto the sensor and cover the join with heatshrink i use one that seals its self with a resin when you shrink it to make it water proof then cover both cables in heatshrink to form another protective layer and replace the rubber sleving anf support brackets and solder the plug back on the end and use heatshrink to seal it again reattach the support brackets and reconnect the plug replace the wheels and the job should be done make sure you check both sides as they may have both gone.

when you test it switch on the ignition and start the engine the light will come on for a few seconds then go out the pump under the bonnet will hiss once then stop road test the vehicle the light should stay off and the pump should not hiss under the bonnet.

hope this helps if not you will have to search the breakers for a second hand one which may not be in any better condition and they are as rare as rocking horse pooh trust me i have looked for one!

another thing that can effect it is the slotted ring that turns with the front hub the sensor has a magnet inside it and when this slotted ring turns it senses it and tells the abs Ecu the speed at which the wheel is turning the Ecu monitors all the wheel speeds if the abs senses that a wheel is about to skid it turns the brakes off it activates the abs mode on that wheel. The trouble is the slotted ring gets clogged with mud grease and metal fillings from the brakes and the sensor is fooled into thinking the wheel is skidding.

POWER SUPPLIE FUSES
Check fuses, 21-10amp, 25-10amp, 28-10amp, 49-20amp and fuse 50-10amp these are power supplies to NATS and the ECM.

Glen

 

[spudd]

cheers for that will save for next time. i still wouldnt have found the missing clip until i removed the dust cap on my fixed hub.the wheel had been off like a whores drawers trying to suss sensor.at the end of the day i cost me (wife) money only me to blame. but it really was one of those thing you only discover on strip down.the reason i posted was so at least others can think back and say hold on neil had a clip missing best check that.

 

[laurieash]

bugger me bought 2 front abs sensors as abs light always coming on.they sheared off trying to remove. paid local mehanic to remove hubs and drill out old sensors. £40 not bad saved gettin me hands dirty.he did drivers side when he removed cap on n/s fixed hub he found the clip that holds the shaft in was missing.so the shaft was drifting in and out upto 20mm+.so sensor ring was drifting away from sensor and causing abs to cut in.so i spent £245 on new sensors plus the mechanics £40 for the sake of a poxy circlip:lol.
have to laugh or i cry.

I feel for you spudd you dont seem to have a lot of luck with that vehicle,i would have set about it with the hammer by now. i just hope is the last of your probs:thumbs Laurie. did you sort that scrach?

 

[spudd]

Cheers for that. yes i hope i cracked it.just the leaky fuel tank to change at the weekend. no not sorted scratch yet. have a body session after this saga is sorted.