Hi guys.
For a while now I've had a strange problem with (what I assume to be) the ABS kicking in for no reason whatsoever. It doesn't happen very often and It's never happened while going any faster than maybe 10-15 mph, but only ever happens when I quickly depress the accelerator pedal and then quickly depress the brake pedal with a very short time period in between. I'm talking less than half a second from pressing accelerator to brake.
Just to explain a little more... The first time this happened was when I pulled out of a car park junction quickly and then noticed there was a speed bump in front of me, so had to quickly hit the brakes after I had just quickly accelerated out of the junction. ABS kicked in and I got the obvious vibration on the pedal but it really hindered my braking speed and I hit the speed bump faster than I wanted to.
It feels strange because the three or four times it's happened, it kicks in even when I'm 101% sure that the wheels were not going to skid anyway.
As said before, it doesn't happen very often, but I'm concerned for the fear that one day, it may not be a speed bump in front of me but something that I really do not want to hit such as a pedestrian or even worse.... another MR2. s:roll: :roll: s:roll:
Does anyone have any ideas where I can start looking or heard of this happen before?
Thanks for the help in advance.
Once again I'm jumping on the bandwagon of the ABS posts because I've had this a few times as well. But only since going onto coilovers.
Are you on stock suspension woody?
The current setup is stock with lowering springs. I never had this issue on my PFL over the two years It was on the road. That car was bone stock.
I know Jonbill had a similar issue. At the time, I suggested that he lean the muck out of the ABS rotors.
I don't recall what the result was. Knowing Jon, he will respond to this with whatever info he has.
I suggest you slow down, be more observant & drive within your limits.
Quote from: "phaeton"I suggest you slow down, be more observant & drive within your limits.
s:lol: :lol: s:lol: s:lol: :lol: s:lol: s:lol: :lol: s:lol: Harsh! Even by my standards.
What tyres, what pressures, how old are the tyres?
When was the last time the brake fluid was refreshed?
What disks, are all calipers working correctly?
Brake fluid changed last year. All brakes absolutely fine.
In fact, did a brake test last week for laughs from 60mph to full stop and abs barely kicked in. Stopped like hitting a wall.
Tyre pressures peachy on low mileage AD08Rs
Quote from: "phaeton"I suggest you slow down, be more observant & drive within your limits.
As stated, 10-15 mph may be a fair few leptoms, but I'm almost certain that these speeds are within my limits. I appreciate your concern none the less.
Tyres are T1Rs 30psi front 34psi rear and replaced full set in January.
I'm not so sure on when the brake fluid was replaced, I checked the level which is OK - good shout though, I will look into this. How can you tell if your brake fluid has degraded/needs replacing?
I've just replaced all disks, pads and dismantled and re-greased all the calipers.
I'll have to have a look if the ABS rotors are gunked up. Thanks for the advice.
Ok, start with tyre pressures, thnkfully your tyres are all quite new, try setting them to 26fr and 36rr
Brake fluid does degrade over the years, best to replace every 5 years or so.
Disks and pads are also fresh so they will be very bitey, best to smoothly wear them in rather than stamping on the brakes because you're rushing to the stop line.
Give it a couple of hundred miles and see what they're like then.
ABS is usually solidly reliable on these cars, the only time where i had problems was with oversized wheels and rubber that had gone hard on the front but was fresh on the back ... so I was basically getting different levels of grip, which is what abs is all about.
Good luck
It's a real strange one. When I said the brakes were new, I meant new-ish. Maybe 600 miles on them now. I'm really not sure what it is. It's strange how it only ever happens in very specific circumstances.
I'll definitely have a go at changing the tyre pressures. I've played around with different pressures over the 3 years I've owned MR2s and each gives a different feel. Thanks for the advice.
I drove Jonbill's car when it had the problem. Remarkably similar symptoms. You could PM him.
I think Mr Roadie 2 had the same symptoms and his mechanic found there was a crack somewhere in one part of the brakes ! can't find the post but the post was only about 6 months ago as I can remember
Jim
Thanks for the help guys. I'll have a good look when I'm on my shift break. I'll try and get a hold of Jonbill too. I really appreciate all the advice. You're a good lot really, no matter what they say...
Out of curiosity, which pads? I've had pads on the daily that where very grabby and caused the ABS to trigger too early, making for very long stopping distances.
They are mintex discs and pads. They stop well and had no issues even when I used them on the PFL.
It's a hard problem to explain because it happens so prematurely when the ABS should not even be near coming on. Can anyone, very simply, explain where I can find the sensors or any other components which may be worth checking? Thanks.
I'm on eBay mtecs. Have been before these issues started.
Mine literally started pretty much as soon as the BCs went on
Ah, Mintex!
I have Mintex M1144 pads on my Lotus.
When the weather is particularly cold or wet they are very wooden when you just start using the brakes. Excellent when there's a little warmth in them but crap when cold and / or wet. I am pretty certain this will be a good part of your problem. You just have to learn to treat them with respect until you have a little warmth in them.
Funnily enough, I still have my problem but I'm planning to have a go at it today, so I'll report back.
I'd characterise my symptom as ABS kicking in about 40% of the time when braking from 10 or 15 mph. So yes, similar!
Please let me know If you find anything out of the ordinary, Jon. I'll then have a look myself and report with my findings too.Thanks
Ditto
Do you get any lights (ABS or otherwise) coming on when it happens? I've been without my car for three weeks but I'm sure my brakes used to feel strange at 20 or below. Part of me thought it was the gearing in these cars which seems to do far more of the braking than I'm used to, so I tried knocking into neutral a few times rolling up to lights and found it more pronounced.
Been doing a bit of research.
number one cause is build-up of dirt on the face of the sensor.
number 2 build up of rust/corrosion collecting in rotor teeth.
number 3 sloppy wheel bearing changing distance from sensor to rotor.
number 4 sensor not fully seated.
Quote from: "Carolyn"Been doing a bit of research.
number one cause is build-up of dirt on the face of the sensor.
number 2 build up of rust/corrosion collecting in rotor teeth.
number 3 sloppy wheel bearing changing distance from sensor to rotor.
number 4 sensor not fully seated.
They all seem logical options, along with
driver hitting brake too hard despite their protestation that they don't feel a wheel is locking
Warped discs causing grab
Slightly sticking caliper/piston causing grab
I'm following this too, as have the same symptoms, although I have put it down to winter tyres and a slightly sticking caliper.
Will see what its like with my summer tyres over the weekend! s:) :) s:)
When I said I did some research: I googled 'ABS operating at low speeds'. The subject came up with one highly technical paper in two parts, that studied it all with oscilloscope traces and ended up finding corroded parts causing the problem. The rest were forum after forum for every kind of car that has ABS.
I looked though them and came up with that list representing what these forums reported.
Reading our own thread: I drove a car with the symptoms, and I've driven my two cars that don't have the symptoms. It's not the driver. Knowing Schazzle and Jon it won't be warped discs or sticky calipers.
It is an amazingly common problem. Almost always on older cars.
Let's see what Jon comes up with.
I still find it odd that it started in my case with the addition of coilies.
But I seem to be alone in this so I guess it was a coincidence. Looking forward to Jon's findings
Quote from: "Carolyn"It is an amazingly common problem. Almost always on older cars.
It's strange because my new '2 is from 2006. Yet my PFL MY2000 never had the problem. And all my scalpers and sliders were cleaned up and re greased so they shouldn't be a problem.
Anyone know where I can find the sensor to check it out?
On the end of the wire going to the hub.
I feel the weight of expectation. [emoji3] I didn't get very far yesterday I'm afraid. I did fix the arb drop links on my datsun tho.
Just to add, if the wheels ARE actually locking not just abs kicking in (you can test this by pulling the abs fuse).. it could also be what I had which was the ABS unit itself failing its job as a bias valve due to getting gunked up, most likely because I got lazy and fitted new pads quickly and just pushed the calipers back rather than letting the fluid and any gunk in the caliper out the bleed nipple... So when the disks/pads were done if you did similar it could also be the issue.. though it does sound a bit more like its the ABS rings.
That is how I last did it to be honest... And every time before that. It is laziness.
Standard practice isn't it if you let the fluid out just remember to replace it
I had a go at mine yesterday and couldn't budge anything so I gave up on just inspecting all 4 corners.
I'm waiting on some diagnostic kit to help me see if one wheel is showing different speeds from the others so I can zero in on which wheel to hit with a hammer.
So, wheel speed sensors seem to be all showing about the same speed when the abs kicks in, so not an obvious reason so far.
I'll have to see what I see on longer use when the car comes of sorn.
Be interesting to see what a real soaking all over with brake cleaner and a thorough blow-out with an air-line would do. I'm suspecting a bit of filth somewhere.
Quote from: "Carolyn"Be interesting to see what a real soaking all over with brake cleaner and a thorough blow-out with an air-line would do. I'm suspecting a bit of filth somewhere.
I'm sure Shnazzle will be along soon [emoji2]
Sent from my iPhone using Tapatalk
Are you saying I'm a little bit of filth?
Quote from: "shnazzle"Are you saying I'm a little bit of filth?
Maybe, just a little...
Sent from my iPhone using Tapatalk
Quote from: "Carolyn"Be interesting to see what a real soaking all over with brake cleaner and a thorough blow-out with an air-line would do. I'm suspecting a bit of filth somewhere.
It looks like I have to dismantle quite a lot of rusty stuff to be able to clean anything - so I'd rather do it to only one corner if I can.
Supports the idea there's some crap between reluctor teeth: m https://www.picoauto.com/library/case-s ... -abs-fault (https://www.picoauto.com/library/case-studies/low-speed-abs-fault) m
I read that one too. A lot of stuff to wade through to get to 'unbolt some stuff to find muck and rubbish'.
I thought (could well be wrong) it was front offside on your car....
Yes, thats what we both thought, but I still have in the back of my mind that it was left rear that I'd tried to remove when I took the engine out, so I suspect that one too.
Ah... might not be properly seated?
Quote from: "Carolyn"Ah... might not be properly seated?
It never moved a mm, it was rusted in solid. But maybe some rust dropped in the reluctor ring. Thats my thought anyway.
Ok so I know what my ABS problem is.
(https://uploads.tapatalk-cdn.com/20170422/5a92034207364bfef26792e2f976f10d.jpg)
Rear left reluctor ring broken.
I think I've seen a pic on here before like that, so maybe not uncommon.
The prob is either the extra separation between those two teeth or possibly that the ring is now loose on the hub and can move relative to the sensor.
In the (probably vain) hope that its the latter, I've glued the ring in place and I'm going for a test drive.
Bugger. So it was the ring. I was at The breaker's today, could have picked up a drive shaft for you...
Well done finding it, you can buy just the rings FLEECEBAY (http://www.ebay.co.uk/itm/TOYOTA-MR2-ABS-RING-ABS-RELUCTOR-RING-DRIVESHAFT-ABS-RING-00-02-/130990774235?fits=Car+Make%3AToyota%7CModel%3AMR+2&hash=item1e7fa897db:g:wf8AAOSwGtNXiJbL) I did them on a Peugeot just tap them into place nice & steady.
Thanks - I've just ordered one. Nice and cheap.
I'll have to read up now on how to get the shaft out of the hub.
How are you getting on with this one?
No progress I'm afraid. I'm away this weekend anyway, so will research it next week.
New reluctor fitted and I reckon it's fixed. No sign of a problem on a run round the block.
(https://uploads.tapatalk-cdn.com/20170506/083dcfcdc7f18b4f3107de23e7f55f45.jpg)
Excellent news, thanks for the update, that's a useful thing to know about.
Was it easy to remove the hub?
Quote from: "lamcote"Excellent news, thanks for the update, that's a useful thing to know about.
Was it easy to remove the hub?
yes, pretty straightforward TBH the hardest bit was reassembling the handbrake link - both caliper & Cable aren't in great shape.
Very interesting.
I have occasional problems with this. Much more noticeable on loose surfaces/dirty roads. On track you're kissing the windscreen before the ABS kicks in. I guess I'll have to check these out.
Quote from: "jonbill"Quote from: "lamcote"Excellent news, thanks for the update, that's a useful thing to know about.
Was it easy to remove the hub?
yes, pretty straightforward TBH the hardest bit was reassembling the handbrake link - both caliper & Cable aren't in great shape.
How does the ring fit onto the shaft?
Quote from: "StuC"Quote from: "jonbill"Quote from: "lamcote"Excellent news, thanks for the update, that's a useful thing to know about.
Was it easy to remove the hub?
yes, pretty straightforward TBH the hardest bit was reassembling the handbrake link - both caliper & Cable aren't in great shape.
How does the ring fit onto the shaft?
Must... not... comment... move away, nothing to see here!
Sent from my iPhone using Tapatalk
In this instance it was a genuine question. [emoji38]
Just a really poor choice of words on my part!
Quote from: "StuC"How does the ring fit onto the shaft?
[emoji52] it's a slight interference fit, so gently drifted on with a plastic mallet.
That's as I thought. So the part is installed with some inherent tension. I was just wondering why your part had failed, thats all.
Thanks.
Quote from: "StuC"That's as I thought. So the part is installed with some inherent tension. I was just wondering why your part had failed, thats all.
Thanks.
Yes. I think the root cause is a little corrosion under the ring. Rust increases the tension and it fails.
I spent a few mins rubbing the shaft down before I put the ring over it.
Fnar.
I was told that it can also be caused by frost, small amount of damp gets in then freezes & causes expansion, whether that is true or not no idea.
That sounds very possible too.
I'm just adding to this with my similar problems.
I started off with very similar symptoms of the wheels skidding and the ABS kicking in when slowing to almost stop.
I too had put it down to a broken wheel bearing causing the ABS ring to get confused.
I replaced both rear wheel bearings but broke one of the ABS sensors (or it could have been the problem) all along!
Wheel bearings arrived before sensor so put them in first. Car was great with no rumbling but obviously ABS light was on and disabled. Drove the same roads I usually do and never locked up once in the placed I previously would.
ABS sensor now replaced but light still on. Exactly the same as before.
Couple of days later ABS light went off on it's own accord. Now whenever I come to a complete stop the ABS kicks in, brake peddle vibrates and makes that horrible ABS noise, but the car does not skid!
Anyone any ideas what's up now?! s:( :( s:(
Well- there's a great bit of software called techstream that Toyota dealers and perhaps some others have. It will show the operator what the wheel sensors are reporting and what the ecu has decided to do with the solenoids.
Such a session helped me diagnose mine [emoji16]
Quote from: "jonbill"Well- there's a great bit of software called techstream that Toyota dealers and perhaps some others have. It will show the operator what the wheel sensors are reporting and what the ecu has decided to do with the solenoids.
Such a session helped me diagnose mine [emoji16]
Cheers. I thought that would be the answer. Getting plugged into Techstream on Ding Day so hopefully get the answer then. Just wondering if anyone else had any thoughts!