Nissan Micra brake problem

chakota

Hi All,
Can anyone out there help me with a problem on my daughters 04' Micra . She is still a learner and last Sunday evening i was with her . She slowed down for traffic lights and lo and behold no brakes She went into back of car in front , not much damage but i limped the 2 mile journey home with some braking. We got the car checked out and the brakes are back to normal again. No fluid loss or leakage could be found , rear wheel cylinders are bone dry. They put it on rolling road and perfect. Because of what happened and no fault being found my daughter is reluctant to use the car. Has anyone any idea as to what could have caused the failure in the first place. Its a dilemna for me as i dont know where to turn next.

Many thanks to anyone who could help .

riget

I've been out the trade a few years, but never known an electrical fault to cause brake failure.
The link you put up seems to be about the brake light switch, can't make the brakes fail (unless you know better).

chakota, when you drove home were the brakes ok or still none or poor?
If we're saying the brakes definitely failed (not driver error) the best I could guess is they overheated, and when cooled they would work ok again.

chakota

Many thanks Bazonix,

I did not know you could have a switch that could fail and cause loss of brakes ... sounds a bit dangerous . Nevertheless i shall give them a ring tomorrow .............Cheers my friend  

chakota

Hi Riget,

My daughter is a learner driver and i was with her when it happened , all was working fine no hard braking or high speeds , so nothing to warrant heated brakes. She was doing about 15 mph coming up to cars sitting at lights and suddenly nothing! i tried the handbrake but too late I did notice when we parked up when i pumped the brakes it brought them up to efficeincy again , so with no apparent fluid loss and brake fluid still at normal level i am at a total loss why it happened .... possibly air in system , but how? the car has been well looked after and done 45,000 miles. I think best thing to do is new seals in master cylinder and a complete clean out of old brake fluid and bled again. What do you think ?

bazonix

no, its not right as correctly stated by riget... but the more im reading, id still have the diagnostics read... the prius had issues due to its electronics... Prius problems put spotlight on car electronics › Japan Today: Japan News and Discussion and mercedes have had a couple of electronic glitches, leading to brake failure...

but a nissan micra is a little wide of the mark.... wishful thinking i guess... the only reason i suggested it was because u told me the car had no mechanical problems, id go with the overheating one too, but i dont know how ur daughter was driving...

riget

The brakes do not fail even if electrically assisted, like if the servo goes, or the abs, the brakes still work.
I would still say they overheated, either the hand-brake left on, riding the brake pedal, or a faulty brake system, if they did overheat, you need to find the reason as the caliper or cylinder seals could be damaged.

car-man

The earlier model of Micra (K11) used to go through rear brake cylinders with alarming regularity, but never had brake failure unless the fluid level had dropped too low and allowed loads of air into the master cylinder, the brake fluid low warning light would have been on for quite a while, so you would have been warned.
The newer (K12) Micra has a different braking system, based on the brakes fitted to the Renault Clio (the K12 Micra has mostly Renault brakes and suspension.)
Brake failure is not very common these days as braking systems are split into seperate sections diagonally, so if one brake fails, you still have others that work.
The only thing I can think of is failure due to overheating of the brake linings or fluid (if the fluid is old, water can get in it and be boiled away leaving air in the system leading to brake failure, brake fluid should be replaced every 2 years.) Having said that, there would still be air in the system and would need to be bled out.

For peace of mind, I would....
1) Have the brake fluid replaced and the system bled.
2) I would have all the brake linings, including the pads checked for overheating...they will show signs of it, as will the brake discs....The discs will show a pink coloured tint to the edges.
3) If she is really very nervous about driving the car again, I would advise replacing the Brake master cylinder.

I would also advise adjustment of the rear brakes, especially if the handbrake comes up more than 6 clicks.

riget

just had a thought, it could be the master cylinder, to test it try pressing very lightly, and lifting off a little as you go.

chakota

Once again , many thanks lads for all your input, i saw the rear brakes with drums off and the wheel cylinders and linings were like new , front pads have been recently been done , discs were of minimal wear. i think the safest option is to renew the master cylinder and brake fluid , i know it will cost a bit to get this done but for safety of my daughter and other road users it would be a small price to pay.

                       Cheers my friends......

petrolheed

was there a pothole or sunken drain cover where it happened. I dont know if youve ever noticed but on a lot of cars if you hit a pothole or drain cover while braking the abs will push your foot off the pedal for a second or so maybe that threw her a bit. If there was air in the system it would likely have only affected one front and one rear wheel.