My '97 Mondeo estate (80,000 miles) has taken to veering mildly to the left on braking. This turns out to be a failure of the Fr RHS brake to operate properly, and it seems that the difference between the 2 front brake would lead to an MoT failure. After checking out the system, it seems that the problem is caused by a failure of the ABS control unit - which I'm told will cost £700 + labour i.e. best part of £1,000 to put right. HJ hasn't mentioned this on C by C breakdown as a particular issue with Mondeos. Have any other Backroomers come across this?
This may be allied to the squawking noise that has occasionaly come from under the bonnet for years!
|
|
Look for the link to the Mondeo owners website in the C by C breakdown and try posting the question there (or have you tried that already?)
|
Thanks for the tip, Micky. I had a look on the Mondeo site, and couldn't find any previous reference. Maybe it is time to post the question there. Normally, the Backroom comes up with loads of replies to a Mondeo question, so I am assuming that this is a relatively rare problem. I guess if was a regular occurence, HJ would have mentioned it in the C by C breakdown
Waino
|
|
|
|
My '97 Mondeo estate has taken to veering mildly to the left on braking. After checking out the system, it seems that the problem is caused by a failure of the ABS control unit
What leads you to suspect the ABS unit? What symptoms does the car display? Does it make a strange noise when braking? Can you feel the brake pedal "pulsing" as though the ABS is activating? Does it do this only during an emergency stop, or every time you use the brakes in normal driving?
The ABS isn't capable of *gently* reducing brake pressure to one wheel, it can only completely release the brake on that wheel until the sensors report an increase in rotational speed, at which point it will allow full pressure again, at the rate of around 18 brake/release cycles per second.
If the o/s/f wheel was not braking at all, you would notice a *very* marked pull to the left, almost dangerously so. It sounds more like a seized piston or caliper to me, or unevenly worn pads or discs. In other words, a more mundane (and hopefully cheaper) brake problem.
|
I tend to agree with Dave that your mechanics do appear to have looked up the most expensive brake part in the book, will sell it to you at 100% mark up and then do the discs and pads, or caliper, or whatever, for free so that your problem is really solved.
Assuming they're right though... I know a lot of people want to keep everything main dealer, but if you're not one of them, and given that this doesn't appear to be a common problem, you could probably source an ABS control unit in a scrap yard and get it fitted by a trustworthy independent, all in, for no more than £400.
|
Thanks for he replies. For years I have known the mechanics who checked it - and it is definitely not a dishonesty job. They checked the brakes on a rolling road and confirmed the big difference - also that it was not the calipers, pads or discs. Suspect that it is solenoid/valve fault in the control unit- but this can't be proved without a great deal of trouble.
The 'pulling to the left' started after the ABS had operated on ice when we had that cold spell about a month ago. A few days later it seemed to correct itself. Then a couple of days ago it started pulling to the left after I had braked sharply - again the ABS had activated. At first there seemed to be no braking on the FR wheel (cold disc), but after a short run today, it seemed a bit better - I checked the heat of the disc and it had had most definitely been operating.
The only strange noise that I hear is the squawk from under the bonnet - usually after I have braked, gone over a bump or when I am just starting off.
Anyone any more ideas?
|
The only strange noise that I hear is the squawk from under the bonnet
Difficult to describe, this one, but a Scorpio I used to have access to always used to have the ABS trigger for the last foot or two travelled as you were braking to a halt. It sounded more like somebody running a stick along a stretched-out spring than anything else, a kind of "brrrrrr" noise that carried on "ringing" for a second or two after you'd stopped.
Is the "squawk" you describe anything like this? It does sound as though there is somethng very strange indeed going on with your ABS, the first port of call for me would be to check and clean up all 4 wheel sensors.
|
The squawk has been there (perhaps less pronounced) for a couple of years, but the brakes were OK previously. The noise is more reminiscent of a belt or water pump bearing going, but all of these things have been checked out.
|
|
|
|
Dave - had this on Rover Sterling, it was the casing of the ABS sensor which had split. New one was about £80 fitted (non Rover dealer), Rover wanted nearly £200 for same work.
|
|
|
|
|
