Yaris ABS sensor replacement

[Travelbuddy]

According to our garage as a result of an MOT, our 19 year old Yaris auto which was built in Japan and purchased new from a UK dealership, has developed a fault with the front offside ABS sensor. When braking at a low speed the sensor thinks the offside front wheel has locked up, so the ABS kicks in.

Is it an easy job to replace the sensor? Can replacing the single sensor lead to other issues with the onboard chip? Any tips would be much appreciated.

[sproutdreamer]

The problem with the ABS sensors at the front is that the housing in the hub becomes very rusty (forged steel) and they can be difficult to remove without breaking them. The front ones have a single small bolt holding them in position and you will be lucky not to shear the bolt. I would make a start with a good dose of penetrating oil (not WD40) for a few days. If you do shear the bolt it is easy to access and drill and retap 5/6mm. A flat screwdriver tappped at the joint with a hammer will part the sensor from the hub. You may just find the ring in the hub is totally fouled with rust chippings and this is stopping the sensor working which is what I found, but as I had bought new sensors I replaced them anyway.. The sensors are only £10-18 each on  e bay not the silly Toyota prices. You will see left and right sensors but they are both the same apart from the small bracket that fits on the brake pipe stanchion, which is handed but you can re-use this.

I have replaced 3 of my sensors (trying to find the fault!) and all is well afterwards. Good luck with it, just try and be gentle with the securing bolt.

 

 

[Travelbuddy]

Thank you Sproutdreamer for the quick and detailed response, which has filled in the majority of my missing knowledge. 

One more clarification, do you know whether there is any difference between the ABS sensor fitted to the Japanese bult and imported vehicle and that built in France and imported to the UK? I ask this as the garage who quoted for doing the repair said they would need to charge me for 2 types of sensor i.e. japan built and french built at approx £40 each, as they were unable to determine using the vin number as to which sensor would fit. BTW the labour charge would be in the order of £150+vat. Also they would not guarantee that changing the sensor would rectify the problem or fail to trigger other brake sensor issues.

 

[sproutdreamer]

As far as I recall there was no difference in the part numbers for the French or Japan built sensors. If you are looking at a cost of about £260 for the garage to do it I would have a low cost go at it myself.

It only involves jacking up the car front nearside, blocking it up for safety. The sensor is very accessible and is only a 5 minute job to remove and at only £15 off e bay is worth a go yourself. Remember that if the garage twist off the head of the bolt securing the sensor they will then charge you for drilling it out and retapping the hole, probably another hour at another £70?

Whatever you do it is still worth soaking in penetrating oil as it will save you money and time. You do not have to jack up the car to soak the bolt just put it onto full right lock and you can get at it to put on penetrating oil from a can.  253155337988 See e bay item number - Ihave bought from these people without problems.

[furtula]

As mentioned above, equip yourself with some penetrating oil, and if possible, soak it up the day before, or few hours before, if you can get to it without jacking the car 2x.

And be careful when unscrewing, do not force it, but try to wiggle it slowly until it starts coming out.

 Better few more minutes here, than an hour trying to fix the mess of a broken bolt.

 

The garage charging such a hefty sum and refusing any responsibility regarding the replacement is a bit cheeky, considering the price for such a simple job.

[Parts-King]

I don't know what the EXACT difference is BUT the Jap and French models have DIFFERENT part numbers, so there is a difference

[Travelbuddy]

My thanks to Sproutdreamer, Furtula and Parts-King for your feedback. I've now taken the step of contacting the eBay supplier with details of our Yaris and are awaiting their confirmation that they are able to supply the correct part. Also I researched penetrating oil and found a 50 / 50 mix of acetone and transmission fluid is the answer to loosing rusted bolts. Need-less to say I will post another update once I've undertaken the work. Fingers crossed and once again thank you for your support.

[Gerg]

I tried the d-i-y acetone/ATF mix a while ago.  When I tried it, my mix was just like trying to stir water and oil, so not very successful.  Hopefully yours is better.

If you are near the North Herts/Beds border, then I have a jam jar full of genuine 'Plus Gas' penetrating oil (taken from a 5 litre can) that you are welcome to have.

[Travelbuddy]

Thanks Gerg for your very kind offer, which i am keen to take up. I live in the south east corner of hertfordshire but next Monday, 13th May we are visiting Bletchley Park, so was wondering if it would be convenient to collect the Plus-gas either on our outbound or inbound journey? 

Regards Steve.

[bathtub tom]

2 hours ago, Gerg said:

I tried the d-i-y acetone/ATF mix a while ago.  When I tried it, my mix was just like trying to stir water and oil, so not very successful.

 

I think you'll find you have to give the mix a damn good shake just before applying it as the two liquids aren't miscible. The idea is (AIUI), the acetone creeps into the the join, dragging the ATF with it. Seems it's the best penetrating fluid known.

I also have a container of plus-gas which I try first. I've never had any ATF to try the alternative.

[Gerg]

I put the two into a small jar and shook it like heck.  I hoped it might turn into an emulsion, but mine wouldn't, just red blobs in a clear liquid.  No one mentioned that on the websites that the recommendation came from.  I already had the acetone and the ATF, so it was no great effort to try this out.  

9 hours ago, bathtub tom said:

I've never had any ATF to try the alternative.

If you are ever over Henlow direction, then I can give you some Morris Liquimatic D2 ATF, or bring a jar if you only want enough to experiment with.

[Travelbuddy]

Gerg, thank you for the offer of some plusgas and atf, which i had intended to collect whilst out tomorrow visting Bletchley Park. Unfortunately my other half has contracted a really nasty cold so we will have to cancel our plans. 

I'm very grateful for the offer and the feedback, hopefully the eBay supplier will get back to me confirming the correct part.

Will update this posting in due course. Cheers.

[sproutdreamer]

It would be interesting to hear the outcome of this-half the interest of the Forum is hearing about problems...but the other half about results is more revealing!

[Travelbuddy]

Ok here's an update. I heard back from the recommended eBay supplier, so went ahead and purchased the front left and front right sensors. Total cost £37 ish, which is less than the cost for a single unit quoted by a garage. Also bought from an eBay supplier 500ml of acetone (£4.99), which i plan to mix with auto transmission fluid and use this to free up any rusted bolts. Next hopefully i can borrow an axle stand, as searching for mine has reminded me that they were borrowed but never returned some years ago. The target start of the job, under the watchful eye of a friendly and former mechanic (thanks to being a member of our local U3A cycle group) is mid June.

Will be in touch.

[Travelbuddy]

On 5/18/2019 at 3:55 PM, Travelbuddy said:

Ok here's an update. I heard back from the recommended ebay supplier, so went ahead and purchased the front left and front right sensors. Total cost £37 ish, which is less than the cost for a single unit quoted by a garage. Also bought from an ebay supplier 500ml of acetone (£4.99), which i plan to mix with auto transmission fluid and use this to free up any rusted bolts. Next hopefully i can borrow an axle stand, as searching for mine has reminded me that they were borrowed but never returned some years ago. The target start of the job, under the watchful eye of a friendly and former mechanic (thanks to being a member of our local U3A cycle group) is mid June.

Will be in touch.

 

OK here's my latest and final update. I searched the garage loft and found the 2 axle stands, the hydraulic jack that I thought had been not been returned and some old auto transmission fluid. The eBay supplier did confirm that both the near side and offside sensors they were selling would suit both French and Japanese built cars. So I went ahead with the purchase as well as 500ml of acertone.

Over the past week the Yaris has been up on the axle stands with both front wheels removed and over a period of 72hrs, a 50/50 mixture of transmission fluid and acertone (well shaken) has been brushed onto the holding bolt and the sensor surrounds.

Today I applied a 10mm socket / ratchet and the bolt and sensor per wheel came loose without trouble. In fact the oil had penertrated almost to the tip of the thread.

Relieved that it had gone well, I withdrew each sensor only to find each had heavy deposits of dust partially covering the electrode. With a clean cloth sprayed with WD40 I cleaned the sensors and pushed them to one side. I then put a small rolled up piece of rag into the sensor chamber and set about cleaning around the lip of each chamber.

It quickly became evident that parts of the once flat surface had rusted and lifted the surface thus pushing the sensor away from the rotating hub. I cleaned these areas with a file and medium emery paper to remove the high points and then with fingers crossed reassembled.

Glad to report that the test drive went well with various speed braking proving that the sensors were now picking up the rotation of the hub and no ABS kick in was evident, nor was there any change to the dash board warning lights, which I was worried about having just cleaned the electrodes.

Ok I have lashed out on 2 replacement sensors, which were not needed. But I'm more than pleased with the result. Finally my thanks to all that contributed to this posting.