VRS Brake Servo Part

[VrsMad]

The VRS has developed the dreaded  N/S/F / O/S/R brake drag problem which after a bit of fuss has been trial and error identified as a brake servo fault.

 

Skoda / TPS want £200 for a new servo (part only). Is anyone aware of any after market / cheaper solution? I don't want to fit a used part on the braking system

 

 

[DanHam]

Are you sure the calipers aren't sticking / seized?

[VrsMad]

Are you sure the calipers aren't sticking / seized?

I'm not 100% sure that it is the servo but everything is pointing that way, changing the rear calliper / hose with new parts has not made a difference. Neither has changing the front with a used calliper from a donor car that was working OK.

 

I wish it was something simple, but taking everything into account including posts on  Fabia/Polo/Ibiza forums (inc. this one) it does seem to point to the servo. It's a fairly expensive part from Skoda and it involves removing the engine mounts/lowering the engine, not the best job al in all!

[DanHam]

Have you checked any of the vaccum pipes aren't split or anything? Mine have split 3 times now!

[ric04vrs]

I'm not sure how the servo could affect just one diagonal of the brake hydraulic circuit,

On the calipers which are binding, have you undone a bleed nipple to see if there is pressure there and whether the binding frees off ?

Sent from my iPad using Tapatalk

[VrsMad]

On the calipers which are binding, have you undone a bleed nipple to see if there is pressure there and whether the binding frees off ?

 

Yep, done that, they release.

 

It's a bit of a strange one. Research on it seems that it isn't that uncommon for the pushrod in the servo to detach from one of the four little clips which locate it in the servo. This allows it to move about and sit forward a millimeter or two. This applies the brakes slightly and covered the pilot holes in the cylinder preventing the heated, expanding fluid returning to the reservoir as the brakes overheat aggravating the problem. 

 

Can't be 100% sure its this, it could be the master cyl, but there don't seem to be many reports of these causing this problem where as there are for the servo.

[VrsMad]

Have you checked any of the vaccum pipes aren't split or anything? Mine have split 3 times now!

Yep, they are OK, I have changed the servo one once. A split vac pipe is unlikely to cause drag it is more likely to cause the opposite as far as I know, which isn't very much!

 

Cheers for the help though

[felicia16v]

you could try slackening the master cyl nuts off a bit once the brakes are dragging, if it free's then yea its the servo if it doesn't then it's possibly master cyl.

[ric04vrs]

you could try slackening the master cyl nuts off a bit once the brakes are dragging, if it free's then yea its the servo if it doesn't then it's possibly master cyl.

Yeah, do that, as that will eliminate the master cylinder

Sent from my iPad using Tapatalk

[VrsMad]

you could try slackening the master cyl nuts off a bit once the brakes are dragging, if it free's then yea its the servo if it doesn't then it's possibly master cyl.

 

Cheers, will have to give this ago, Doesn't seem easy to get to the bolts with the expansion tank/pipes still in place but if could be worth doing.

[felicia16v]

But still easier than changing the servo to find it still does it? Do you have the release tool to get the servo off the brake pedal? As it is a royal pain to do without

[VrsMad]

But still easier than changing the servo to find it still does it? Do you have the release tool to get the servo off the brake pedal? As it is a royal pain to do without

I don't have the tool, I was looking to make something (e.g. from an exhaust clamp) like the Haynes manual suggests but I'll probably by another clip just in case that doesn't work & it needs to be drilled/cut out! Have you done it, if so how did you manage it?