[DuncanNixon2004]

Car is one year old with 18,500 kilometres on it. It is my wife's car and she has reported that the brakes are grabbing. I have driven it and found no problem EXCEPT on those rare occasions when she is not using it; it is cold; and I am the first driver.

Having put the first 11,000 kilometres on it myself driving to and around and from the Yukon I am well aware of how the brakes should work.

She had no complaints prior to the brake switch recall performed.

Now, when the car is cold, even the lightest touch results in a "grabbing" feeling. Most uncomfortable!

Once the vehicle has been driven for a short period the brakes revert to their normal self and the "grabbing" disappears.

Any thoughts?

Back to the Yukon in a couple of weeks so if it is a real problem it should be seen sooner rather than later since the only dealer is in Whitehorse...

 

[KTPhil]

Check the switch adjustment. Did they replace pads/shoes or do any other brake work at the same time?

 

[DuncanNixon2004]

If they did any other work it was not noted on the bill.

I understand the switch was just related to when or if the brake light came on.

 

[KTPhil]

Not 100% sure, but I think the electrical portoin of the switch not only works the lights, but helps determine brake action through the ECU, doesn't it? That might make adjustment have an effect on braking action.

 

[An04Prius]

what you describe sounds like dampness in the brakes which dissipates with a couple of stops. Has the weather been unusually rainy ? damp ? high humidity ? any reason to suspect water getting into the wheels ? from washing, etc ?

driving thru any flood zones lately

 

[DuncanNixon2004]

You will notice that I am located in Victoria. While usually referred to as the 'wet' coast of Canada, Victoria itself is not unusually wet. If you want wet go to Vancouver or Prince Rupert.

The 'wet' portion of the year was essentially over before the brake recall was effected. So maybe the resultant grabbing is consistent with the adjustment.

I do have a great deal of difficulty believing that a simple light switch could control brake action. Presumably all 2004's have had this recall. The only other comments I have seen have been related to the sensitivity (or lack thereof) after the fix, nothing about brakes being affected.

 

[mikepaul]

I can make my brakes grab by 'hitting' the pedal with my foot while attempting to 'press' it, but no more than before the brake switch recall.

If that first 1/4 inch of pedal movement happens too fast (accelerometer?) the car thinks it needs to stop NOW...

 

[An04Prius]

I noticed no difference in braking after having the brake swithch recall done.

 

[mrv]

Not 100% sure, but I think the electrical portoin of the switch not only works the lights, but helps determine brake action through the ECU, doesn't it? That might make adjustment have an effect on braking action.

My husband had to take his 2004 back to the dealer after they botched the brake light switch recall.
Go over a bump, brake lights go on. He couldn't use cruise control because the brakes were constantly shutting off the cruise on him...
The brake lights would go on by themselves after he left the car parked somewhere, just by the weight of the brake pedal itself. He'd constantly be asked by co-workers if his car was OK... Then one day he needed a jumpstart because his car wouldn't start, so that pushed him to take time off work to have the recall work fixed...
(Usually the brake light switch recall complaint is that the interior light dimmer wheel switch was disconnected, and occasionally that you'd have to floor the brakes to get the new brake switch to catch... My husband seems to have the only reported too sensitive installed switch...)

Otherwise, on my 2001, if I leave it parked for the weekend, particularly if it has been damp/wet out just before parking it/that weekend, I find that my brakes will sieze up on the brake dust. I have to use the accelerator to brake free and inch out of my garage, squeaks a bit, but is usually fine by the time I'm out of my driveway...

 

[DuncanNixon2004]

What MRV describes is what I believe my wife is telling me.

The only difference is that it doesn't have to be parked over the weekend, just overnight. Oh, and that it's a 2004.

 

[Pepa]

I've also noticed the "grabbing" effect, for example after rain, when braking at very low speed while the computer transitions from the generator braking to regular brakes. That is normal - the computer has no way to figure the braking effect of the pads, and so the "transition" may not always be smooth.

And I'm also experiencing reverse effect - going downhill while gently braking, the braking force drops considerably when the engine shuts down at 40pmh. I have to press the brake pedal harder.