A little strange but hopefully an easy fix.

Basically the brake pedal and brakes seem to go VERY hard and dont slow me down at all. Every time you pump them it gets harder and harder then eventually goes soft and cycle starts again.

When they are soft they work as it should, almost feels like pressure is being built up stopping something from working as it should.

Any ideas as to the cause and more importantly, the solution ?

Pads and discs are more or less new and brake fluid is nice and clean.

Thank you for any help or advice,

Joel

Seems like you've got a split brake servo vacuum pipe.

:(

Expensive ? Easy fix ?

I'd agree with the servo fault. Is it like pressing the brake when the engines off?

The pipe is in two parts, so around £40 ish in total and quite straight forward to fit. Have a look at yours and check for cracks/splits where the connectors are and you could temporarily tape it up.

I'd agree with the servo fault. Is it like pressing the brake when the engines off?

Yes mate.

Thanks for the replies, will have a butchers tomorrow but not 100% sure what im looking at lol. Dont suppose anyone has a picture to hand where they can label the area ?

If you look at the brake servo, the big round black thing that sits behind the brake hydraulic cylinder on the drivers side bulkhead, you'll see running from it a hard shiny black plastic pipe. This pipe is clipped to the bulkhead and then turns 90 degrees and connects to the vacuum pump on the passenger end of the cylinder head. There are various components within the pipe that are pushed into it, examine closely for any splits within the pipe.

Just to update:

Managed to have a look and at first all seemed ok. Got a friend to pump the brakes and got some major hissing then with another look and found the split.

Ordered what I hope is the right part come to about £26 I think it was.

Thanks for the help and will keep the fingers crossed

To finish and close up this thread

Replaced the servo pipe and brakes are now functioning again

Think I may have been driving with "dodgy" breaks for quite some time as every time I tap them now I get thrown into the windscreen lol.

They have literally never been this good. I would suggest for the small cost of this pipe £26+vat and ease of fitting to try this "fix" if your breaks feel not as good and have recently changed the pads / discs.

312's ftw

Brilliant, glad to hear you got it sorted

I'd hope this sort of issue would be picked up by an MOT tester. I do wonder if the brake roller tester rules supreme though, and if it gets a pass on that it doesn't matter. I suspect the braking force required from a car for the MOT is surprisingly low, otherwise many vintage cars with standard brakes would never pass.

Dont think it would get picked up on an mot, if anything it would come up on a visual inspection of the engine bay.

Dont think it would get picked up on an mot, if anything it would come up on a visual inspection of the engine bay.

It should be picked up on the MOT if they're doing it right. There should be a noticeable difference in pedal feel with engine running and not. Providing the car is fitted with a servo of course.

I always look at the servo hoses when doing a test and I've found a few defective ones, however as I'm not allowed to remove engine covers , access isn't always good. As well as the under bonnet check, the tester will exhaust any vacuum by pumping the pedal and then start the engine with pressure on the pedal to check if there is servo assistance.

The Roller Brake Tester (RBT) measures the weight applied by each brake. Each vehicle has a braking weight and a certain minimum percentage of this weight has to be acheived by the brakes. For the service (foot) brake it's 50% with each wheel making a contribution, imbalance on a steered axle within limits and no excessive grabbing or juddering. The parking brake has to make 16% or 25% depending on the type of hydraulic system fitted to the vehicle.

Brake servo pipes have been cracking for years on VW group cars, they had a recall for them on some Octavia 1 models, though given the same construction and materials still in use for them today, it's hardly surprising that they're still failing.

Thanks Fordfan, that's interesting information. Is there any guidance as to the pressure the tester puts on the brake?

To finish and close up this thread

Replaced the servo pipe and brakes are now functioning again

Think I may have been driving with "dodgy" breaks for quite some time as every time I tap them now I get thrown into the windscreen lol.

They have literally never been this good. I would suggest for the small cost of this pipe £26+vat and ease of fitting to try this "fix" if your breaks feel not as good and have recently changed the pads / discs.

312's ftw

where did you get the part?

Shann - I just ordered it through my local garage. Always friendly and knew what I was after as seems to be quite a common problem.

Re MOT - The breaks did work, they stopped me. However under lots of use they got harder and harder. Not sure how many goes they have but I reckon it would have passed if only tried a handful of times. May have also helped in having 312's on ? Maybe would be more obvious with using the standard set up ?

Thanks Fordfan, that's interesting information. Is there any guidance as to the pressure the tester puts on the brake?

Not really, but the pressure on the brake pedal is more than what would be normal and for a longer period of time. Another test that is done is closely inspecting the hydraulic system under pressure using an assistant. Over year later I still have a colleague moaning at me about the time that a metal brake pipe burst on his car whilst I was testing it.

A servo just provides assistance for the brakes, if it ceases to work it just means that you have to apply a lot more force to the brake pedal to get the car to stop. The problem is that these aids are taken for granted and when they're not there, people can't cope.

Just another update

This pipe seems to have fixed the engine shake when switching off, which I though was a clogged up egr lol and also the EML has gone off which was showing an open valve (or something similar) error. Also the recirculation air stays on rather than going off after 10 seconds and never coming back on

Joel I have the same symptoms do you have a part number for the one you ordered?

Sorry but dont know the part number :(

Just let the local garage know what I was after and they phoned their suppliers. On the invoice it is down as "S/F Brake Servo Pipe" and also written as "BSP Brake Servo Pipe"

Was told the part had been "modified" to prevent the problem in the future but looked more or less the same as the pipe I took off.

Will try and get a picture for you over the next few days

Thanks @joelk2010

Leaving over to the mechanic tonight to see if this is an issue on mine so will know better tomorrow afternoon!