No Brakes

[Alias]

Hi,

My girlfriends just called me from work and said that when moving the car around the car park the brakes just failed on her. She said they now seem fine again but this is now the second time this has happened, both times theres been a complete loss of brakes but then they quickly return and feel fine.

The first time we thought it was just because it was about -5 and they seemed fine directly afterwards so didnt really think about it any more. However its 8 degrees today and the car has been used this morning so thinking it might not be a random one off.

both times she's said that the pedal has felt normal when the brakes failed and they have quickly returned again afterwards.

Any help is muchly appreciated.

 

[slob]

What ever you do get to a garage and get them checked out. Two days after i bought my 172 i was driving a long a fast road up to the motorway in edinburgh and went to put my foot on the break and felt nothing (not a nice feeling) after a few panicked pumps they started to work again luckily ther was no traffic backed up is all i am saying as thier normally is at this section. The breaks were then working again but i knew something was wrong so was taking it easy. About seven miles later i went over a man hole cover near my house and heard metal bouncing about i then lost all breaking whatsover and managed to pull of the road and got a mate to collect me with a trailer. Turns out the pads were so worn they actually fell out with the brake fluid gushing out after them. No mention of this was in the MOT two months earlier apart from Advisory " passenger side jacking mount slightly damaged" good MOT station eh. Spent £550 on new discs and pads and new rear callipers wasnt taking the chance after that scare. So take a look at the pads but just be warned, I didnt think a cars brakes would fail that badly was just lucky i was in a thirty. For the record it was my rear nearside pads that fell out and are still lying around somewhere on captains road:dapprove:

 

[Dave..]

Brake fluid would not be gushing out if the pads fell out.

My advice would be to get the brakes bled. Being the cheapest and simplest option, then if that doesn't solve it, you'll know the problem lies deeper.

 

[slob]

Well i dont know what that fluid was that was lying around at my rear tyre. Must have been melted ice cream or something.

 

[Dave..]

Brake pads don't hold the fluid in

 

[slob]

Well the other junk that does I was basically left with just a calliper I am no mechanic so I don't know the exact names ect.

 

[Alias]

She's going to get the fluid checked today before coming home again so can at least rule the cheapest option out first. Upon quick glance the brake pads seemed ok but I'm not 100% on this.

Presume bleeding the brakes is a case of loosening a nipple and pumping the peddle gently until there's no bubbles in the fluid coming out?

Does the 172 use dot 4 or 5.1 as standard?

 

[Dave..]

Dot 4 will be fine. As will 5.1, don't use dot 5, as it's silicone based.

 

[DrR]

I've had my brakes "not work" it's usually after washing it though.


slob your use of break and brake offends me.

 

[jenic]

Dot 4 will be fine. As will 5.1, don't use dot 5, as it's silicone based.

I was told the same so got 5.1, whats wrong with 5?

 

[Dave..]

Damages every seal it comes across.

 

[Alias]

Does 5.1 have an real advantage if you've not upgraded brakes and got braided lines etc?

She's had a quick look today and said one of the discs has rust on it and doesn't look like the pads in full contact with it - did forget to ask her if it was front or back though!

 

[Alias]

So Soph came home from Norwich late last night and the brakes gave up twice on the way home - at much faster speeds than previous times, again after a second or two they worked fine again but think the cars going to have to stay off the road now until it gets seen next week. then got to figure out getting it from Chelmsford to uxbridge with unreliable brakes!

 

[slob]

@ rollo i was pritty pissed when i wrote that so not to bad:approve:

 

[justin_]

it could be air lock in the system bleed the brakes and check pads. then if you havent brought new calipers check the piston and seals inside the caaliper.

 

[Bassplayer]

Quite a common problem. Almost certainly the master cylinder. Easy test. OK, press fairly hard on the pedal, then release it slightly, just a gnats, then press again. The pedal will probably drop. You can almost "ratchet" it down to the floor like that if this is the fault. It is caused by wear in the seals allowing the fluid back into the resevoir. The reason it fails intermittently is because she is probably braking lightly, releases the pedal a bit and then, bingo, no brakes. Air in the system wont cause this. Only other cause could be old fluid. Be safe, change the master cylinder and the fluid!