Hello 

Ive had my mk1 se for nearing a year now and since last week ive noticed.. When i come to press brake pedal slowely it goes all the way down to the floor with no braking effort but if i brake at a medium to fast pace it feels normal. Pads and disks all round are fine and there are no leaks. I havent yet checked fluid. Any ideas? 

Sounds like your master cylinder is shot and might be leaking fluid past the seals, check fluid level and check to see if there's any fluid in the servo.

1) - is  brake fluid level dropping.

2) one quick way ( I found out years ago ) to check for fluid in servo and hence leaky master seals is to do a quick stop and look for a bit or more of WHITE smoke (as brake fluid burns white) on braking or at take away . ( Not Maccy D).

This was on an older petrol model ,pre cat, so I don't know if CAT or ( as you do not say engine) if this would happen on a diesel .

13 minutes ago, VWD said:

1) - is  brake fluid level dropping.

2) one quick way ( I found out years ago ) to check for fluid in servo and hence leaky master seals is to do a quick stop and look for a bit or more of WHITE smoke (as brake fluid burns white) on braking or at take away . ( Not Maccy D).

This was on an older petrol model ,pre cat, so I don't know if CAT or ( as you do not say engine) if this would happen on a diesel .

 

No, a diesel uses a vacuum pump, there's no manifold vacuum so no telltale smoke.

sep- as Wino's sig says, it might be easier if ALL posters could give model details on avature. If OP's car is petrol ,then that test would work. If not as you say it wouldn't. I passed on my experience in case it might help to diagnose on symptoms rather than stripping things down.

1 hour ago, VWD said:

sep- as Wino's sig says, it might be easier if ALL posters could give model details on avature. If OP's car is petrol ,then that test would work. If not as you say it wouldn't. I passed on my experience in case it might help to diagnose on symptoms rather than stripping things down.

 

OP said it's an SE at the top of the thread, SE are all diesels.

 

Also OP self-identifys as a VRS SE called Ben, so he's double definitely a diesel.

Edited 16 October, 20196 yr by sepulchrave

Nuff said- but model and fuel might be better . I've only got Haynes for reference and it don't say anything about models- only petrol or diesel. i was trying to save OP the trouble of taking the master off and the hassle of getting a master or bleeding brakes & clutch and then  getting the part.

OP- as I've posted elsewhere on this site- ECP are doing an up to 50% discount for 7 days. Might be a cheap way to go ,if you need a mastr .

7 hours ago, sepulchrave said:

Sounds like your master cylinder is shot and might be leaking fluid past the seals, check fluid level and check to see if there's any fluid in the servo.

How do i check for fluid in the servo? 

 

How do i check for fluid in the servo? 

So my model is a 1.9 tdi se pd130 model how do i check that the servo is full of fluid? Also my clutch is fine if this helps the diagnostics? 

Just checked my fluid aswell and its bang on? Next step be to bleed them? 

4 hours ago, Bensvrsse said:

how do i check that the servo is full of fluid?

You don't; you check the brake (and clutch) fluid level in the brake master cylinder.

 

Since that appears to be OK, I'd suggest looking for a vacuum leak.

In

4 minutes ago, KenONeill said:

You don't; you check the brake (and clutch) fluid level in the brake master cylinder.

 

Since that appears to be OK, I'd suggest looking for a vacuum leak.

So basically need to check from the vac pump to whatever then to servo? 

First step would be bleeding the brakes with a pressure bleeder.

 

A vacuum leak from the servo or pipe work would cause a hard pedal with extra effort required to stop rather than pedal travel.

Okay so to my previous post about my brakes. Whats happening is if i go out on a journey and i spend a long time with out using the brake. If i was to apply the brake at a steady pace it would go down to the floor with very little braking effort but then if i take my foot off the brakes and then re apply they work perfectly? But if i keep my foot on the brake and apply pressure the pedal slowely depresses to the floor. Now ive stripped front and rear brakes. Cleaned and unseized everything and then bled up the system. The brakes are working loads better but still have this pedal issue? Theres no loss of brake fluid at all. Only thing ive noticed is the vacuum solenoid box above the drivers front top mount is buzzing? Is this normal? 

Any help is greatly appreciated thank you 

 

Have you bled the ABS block using VCDS? It's essential.

4 minutes ago, sepulchrave said:

Have you bled the ABS block using VCDS? It's essential.

No as i dont have vcds? 

1 minute ago, Bensvrsse said:

No as i dont have vcds? 

 

Then you have air trapped in the ABS block.

Just now, sepulchrave said:

 

Then you have air trapped in the ABS block.

I can get vcds. Is it a messy job? 

15 minutes ago, Bensvrsse said:

I can get vcds. Is it a messy job? 

 

Not at all.