Brake pedal goes to the floor.

[pete681]

Hi, my sons 10 month old Polo has an intermittent fault with the brakes. Sometimes when he's stationary at the lights with his foot on the brake, it will suddenly go to the floor. The car is now with the local VW main dealer who say they can find no fault. We are reluctant to drive the car as no parts have been changed and we feel the car is not safe to drive. I have looked throught many posts on a number of different sites about this fault condition and the component that becomes the top suspect is the Main Brake Cylinder. The garage still insist that this would have shown up in their checks and won't budge. Can anyone suggest what he does next to try and get them to take some action.
Thanks very much.

 

[iain90210]

It is their responsibility to deal with this fault. You will have to persevere until you get satisfaction and not allow them to fob you off.

You will have to go up the food chain in the organisation until someone with authority decides to get this problem sorted. If the local manager won't do this then find out what the complaints procedure is and go to a higher level.

I would consider writing to a motoring journalist like 'Honest John' in the Telegraph. I am sure VW would be keen to avoid bad publicity. After all the car is not even a year old.

In these circumstances surely it wouldn't be too hard for VW to replace the hydraulic system in it's entirety.

 

[JohnD]

Your son will probably be insulted by the suggestion but it is not unknown for people to put their foot on the clutch pedal by mistake. Espcially people moving between Automatic and Manual cars. Obviously this does not apply the brakes. Volvo had a spate of this happening some years ago. If it ever happens again see if you can get him to apply the handbrake and look down at his feet to check (or even to apply the clutch with his left foot and see if he can).

 

[pete681]

Thanks iain90210 and johnD for your views. My son is reluctant to pursue the matter as he has been told that the back brakes were set too low and this would set the pedal height lower than it should be. Also told the master cylinder can not totally fail as two diagonal brakes would still operate.
I have spoken to various legal personnel and their view is a case is difficult to prove unless there is some sort of proof. With this in mind my son says that he will take a picture with his mobile when the pedal goes down again. The garage is happy to accept this and pursue the matter further but to what extent I wonder?
Once again thankyou for your inputs. I will let you know any development.

 

[libby lou lou]

while on this subject, my daughter, polo about 18mnth old, has complained to me of grinding on the front brakes, only happened about 4 times, no bad effects, just grinding,can't see nothing wrong, good pads etc, i know this post does not help your problem, it,s just concerning me what iv'e just read of your post, and felt i needed to mention this, with it being a new polo

 

[JohnD]

Is the brake cylinder on the driver's side, or is it built for a LHD car with a linking bar to convert to RHD? Linkages sometimes have lost movement (though the garage should know).

 

[pete681]

To answer to your question JohnD the brake cylinder is on the drivers side.
Thanks libby lou lou for your input, my son has also complained about a grinding noise but when it happens the cars brakes are not as effective and its stopping distance is increased. The dealer puts it down to rust forming overnight on the discs. Sounds feasible but they have heard it all before and seem to have an answer for everything.

 

[Belle427]

any rust that forms overnight is cleaned off pretty quickly when you start using the brakes so thats a load of *******s,id be looking at problems with the master cylinder or air entering the system to cause the problems you describe

 

[johnwr]

ch427 is correct about the rust that forms overnight, it's gone after the first application. The main problem is the brake pedal going to the floor, the only way to check whats happening is to fit a pressure gauge to each brake circuit and then see what happens, but not many people will have a couple of 140 bar pressure gauges to hand. If you press very lightly on the brake pedal and the pedal goes down, then fluid is leaking past the master cylinder seals. It's no good stamping on the pedal as this will force the seals out and make a good seal. I wouldn't take what main dealers say because there heads are up their fundimental orifice
hope this helps johnwr

 

[libby lou lou]

pete 681

can you tell me the mileage on the polo, does he drive the car heavy,like fast then slam on,have you had a service yet? it's just i can't get my head round the grinding, even less with your brake failure, would like a bit more info as i need to look into this a bit more, the more info the better, thanks. the master cylinder is suspect inmy head at the mo.

 

[pete681]

Thanks for your inputs ch427 and johnwr, and to answer libby lou lou, the mileage on the Polo is 5,200 and he doesn't drive it heavy. The grinding sound baffles me and like I said thats when his brakes are less effective? In my head I am trying to link the grinding noise with the brake pedal dropping but I don't know if its 1 fault or 2. He collected the car tonight, it was at the dealers five days during that time it had its first service and the braking fault was looked at.
I agree with what you said ch427 about the rust, as for the brake travel its got to be the master brake cylinder.
I have been told by the service manager that the car had been wired up and driven to and from the garage by one of the mechanics, so I guess this must be what you have mentioned johnwr, thanks for that because I didn't fully understand what I was being told by the garage. I know what you mean about the leaking past the seals, a mate was explaining the workings of the master cylinder last night and it seems the most likely cause. I asked the service manager to replace the master cylinder under warranty this morning and he said VW would not allow him to fit a replacement unless it was definitely faulty i.e. leaking fluid.

 

[libby lou lou]

thanks foryour reply, are you aware that your polo isn't due for it's first service until 20,ooo miles or, two years ?

 

[pete681]

No. but now you mention it my lad did show me a piece of paper and it the items listed did seem to be of a visual check. Do you know if this is chargable?

 

[needtonoplz]

to be honest, if you're really concerned go somewhere else for a second opinion, it can't hurt

 

[johnwr]

The service manager say's that they will only replace the master cylinder if it is leaking, what a joke, if the main seal on the front piston is allowing fluid to seep past it goes back into the reservoir, so it won't leak externally. What a moron. I think a few years training and going to a technical college might just give this plonker an understanding how cars work.