I have a Carlton Estate, many miles under its belt but still a good workhorse that has started shuddering when braking hard.
As it is possible to feel the brake pedal fluctuating combined with a noise a bit like the ABS coming into effect I assume a warped disk.
Does anyone have any other suggestions before I start replacing all the disks to find out which one is the culprit.
Could I get this effect from a worn front wheel bearing? I believe I can detect a very slight amount of slack in one wheel.
Over to you experts!
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Jack the car up and see if you have any play in the wheel bearings or track rod ends .But the most common cause for your symptoms is a warped disc and you need to replace both with new pads.
regards Andy
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Tony,
You should also check the rear drums for ovality if drums are fitted. This is easily done by driving and gently pulling up the handbrake with the button depressed. If a drum is oval, you will feel the lever moving up and down.
I have a carlton which also has had juddery brakes, and they seem to be very critical on run-out. Try and borrow a dial guage and measure it. It does not want to be much more than 0.15mm.
If you do fit new discs, you MUST check the run out before you can be sure they are OK. A tiny piece of muck behind the disc on the hub will cause them to run out of true. This will lead to one part of the disc catching on the pads first, which will wear that part out. This gives rise to 'thick thin', where the thickness of the disc varies around its circumference, and causes brake fluid to be forced back to the master cylinder giving a juddery pedal. Warped discs just tend to make the steering shake on braking. Because a carlton has a steering box, with intrinsically more free play in the system, I think they are more prone to shaking than rack and pinnion cars.
Hope this helps.
Mike
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Thanks to the 2 Andrews, Mike and David for their good advice. I'll certainly take note if I need to change the disks.
I also wondered if the noise I hear "like the ABS operating" is actually that but operating at the wrong time, i.e when the wheel has not locked up. Has anyone experienced this problem with ABS?
Thanks for any further tips or advice.
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Tony - your symptom reminds me of something similar with a 89F 205 I once had. At about 15K miles the (front) discs were skimmed to cure pulsating brakes. Within another 12-15K the problem was recurring, so I assumed that the discs were of uneven hardness, and swopped them for new ones. I didn't keep the car long enough after that to prove that as the cause, but it is an idea.
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Tony - If the front disc(s) are distorted (suffering from DTV-Disc Thickness Variation - that's the technical term!) then the steering wheel will shudder and vibrate quite badly under heavy braking.
Mike is quite correct in his suggestion for checking for rear drum ovality - a problem with some Transit minibuses some years ago I recall with a grimace!!
ANY dirt between the hub flange and the brake disc will cause brake judder before long. It is VITAL to clean the hub/disc mating surfaces before fitment.
Even after fitting new discs on some models in our workshops, we are forced into skimming the new discs on the car with a special on-car lathe to achieve satisfactory run-out measurements!
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It is common to take the ABS warning light out on cars with an ABS problem ie sensor or computor especially auction cars .
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Hi all
I also have a Carlton. If Tony's is one of the later ones it will be fitted with disks all round. Therefore oval drums cannot be a problem
Just a thought :-)
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Alyn,
Yes I have an all disk model. No drum handbrake thank goodness.
Problem solved by changing the rear disks.
The outer, visible faces, of the disks were OK but the inner faces were heavily rusted. The car is used frequently but the symptoms appeared instantly, not an increasing problem but from one day to the next.
Regards,
Tony
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