Member Since: 09 Sep 2005
Location: Scotland
Posts: 619
Shake/Vibration When Braking At Driver Side Front
On using my vehicle for the first time for a couple of weeks, due to coronavirus, there is now a severe low frequency shake/vibration (approximately 1 Hz) coming from the front driver's side suspension, which is particularly severe at low speeds as the vehicle comes to a stop. A slight pumping effect can be felt on the brake pedal.
If the vehicle is driven in reverse and the brakes are applied the problem does not occur.
When the vehicle was first started the special programs off message was displayed and various warning lights came on when the starter motor was turning over the engine, but these disappeared when the engine started (due to the battery not having sufficient charge to maintain voltage when the starter is drawing the high current in order to start the engine). The suspension had also probably dropped bit in the time the vehicle was left standing.
Any thoughts on what the cause may be?
26th Apr 2020 10:28 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4627
Most likely brake caliper sticking causing excess heat which can cause a hot spot and ultimately warp the brake disc, hence the pulsating sensation.(disc buckled)
It can occur if a vehicle has been unused for a prolonged period. You might get away with strip / clean and lubricating the sliders. Also, make sure the tyre pressures are correct, but it is likely it will need new discs and pads.yµ (idµ - eAµ) ψ=mψ
26th Apr 2020 11:51 pm
Globetrotter448
Member Since: 21 Mar 2017
Location: Londonderry NSW
Posts: 1782
+1 on the brake disk, but could also be a wheel bearing
27th Apr 2020 4:50 am
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13611
Plus 1 , ^^^^^^^
Also Apologises in advance, never heard a noise being described in Hz Before and was curious
Quote
What is the normal hearing range for humans in Hz?
Humans can generally hear sounds with frequencies between 20 Hz and 20,000 Hz (the audio range or hearing range) although this range varies significantly with age, occupational hearing damage, and gender. Most human speech communication takes place between 200 and 8,000 Hz and the human ear is most sensitive to frequencies around 1,000-3,500 Hz.
Gary ... as i read it, the noise (which may be of any frequency itself, so you would hear it) is happening about once per second.
27th Apr 2020 6:55 am
Bungle
Member Since: 07 Apr 2015
Location: Wanborough
Posts: 254
A wheel bearing would have to be very bad if you could feel it like that.
I'm with the votes for sticking caliper causing the disc to warp.
27th Apr 2020 9:24 am
zig
Member Since: 09 Sep 2005
Location: Scotland
Posts: 619
The vehicle had only done 3/4 of a mile before I noticed the problem and on touching the wheels and discs there was very little in terms of a temperature rise and they all seemed to be much the same.
However, I suppose the problem may have occurred on my last trip prior to the coronavirus shutdown and I might not have noticed it with my radio on. My last trip being 40 miles of motorway driving followed by 2 miles on A road. This trip occurred late evening with little else on the roads so the usage of the brakes would have minimal anyway (only 3 sets of lights and they may have been green in my favour).
I have checked the tyre pressures and they were fine. I did have all tyres replaced at the end of January so I will check all the wheel nuts. I will also remove the driver's side front wheel and check in that area.
To better describe the problem I am encountering I am getting a short burst of shaking/vibration which is occurs approximately once a second once once the brakes are applied.
I apologise for using terminology in describing my fault that some users of this forum may not be familiar with. A Hz is 1 cycle per second. Hz is an abbreviation of Hertz which was named after Heinrich Rudolf Hertz who proved the existence of the electromagnetic waves, as predicted by James Clerk Maxwell. Hz can be used to define the frequency of any phenomenon.
27th Apr 2020 12:07 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4627
Given you had the wheels off in January it might be worth having a look at the inner wheel boss mating surface. (where the wheel meets the hub/disc mounting surface)
It's unlikely as you have been driving the car since the wheels were off, but any damage or contamination between these surfaces can cause your symptoms too. When it happens its usually a small fragment of stone or other foreign matter has attached itself to either surface, which prevents the wheel mating correctly and causes an imbalance.
You say its pulsating @1 r/sec, is this at a particular speed, or is it the same rate when braking at higher speed?
A wheel bearing / ball joint is a possibility too, but this should be obvious if you jack up that corner and try to rock the wheel whilst holding it in the 9 & 3 O'clock position, and again in the 12 and 6 O'clock. There should be no free play and no coarse feel / noise when the wheel is rotated.yµ (idµ - eAµ) ψ=mψ
27th Apr 2020 1:57 pm
zig
Member Since: 09 Sep 2005
Location: Scotland
Posts: 619
Problem was caused by corrosion on disc which had built up due to vehicle not been used for a couple of weeks due to coronavirus. Sorted by fitment of new front discs and pads.
19th May 2020 8:23 pm
Admirable
Member Since: 19 Jul 2015
Location: Fife
Posts: 1011
Due to the lack of use, the brake pad has been in the same position for a number of weeks. This will result in the pad sticking to the disk, any dampness or wet weather driving on the last journey will add to the issue. I would suggest driving a few miles and applying the brakes gently for a few seconds, not stamping on the pedal, this will remove the imprint of the pad left on the disk which is causing the vibration.
19th May 2020 8:58 pm
Admirable
Member Since: 19 Jul 2015
Location: Fife
Posts: 1011
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