Master Cylinder Adjustment?

[boabym]

Hello guys,

Does anyone know if there is any adjustment in the master cylinder piston rod? Or can the servo be adjusted in any way? Cars a Leon FR tdi. I've had a new cylinder fitted but sommats holding the brakes on. Garage is at a loss at the moment

 

[Muttley]

I'd be surprised if that was a master cylinder issue. Binding brakes is most often either a stuck caliper or handbrake linkage. Just possibly the pads are stuck on their tracks, but there would have to be serious corrosion or a build up of brake dust to make it noticeable.

Is it just one wheel or more? Slightly stuck on (warms the disc up) or full on (can't move the car)?

 

[boabym]

So far 2 sets of front calipers,a flexi pipe on nearside front and 2 master cylinders! And they are still binding on! Oh and 3 sets of brake pads as well. Seems to be mainly the front offside which is binding now and thats a freshly refurbed caliper.

 

[Mark300zx]

Have you done a vagcom, maybe the abs unit?

 

[boabym]

Not yet Mark,thanks for the suggestion.

 

[Steely]

have the rear calipers been dismantled at all?

make sure that the stepped slide pin and the smooth one are fitted the right way round which hold the caliper to the hub, causes slight binding,

I had this very same issue,

As for the servo and master cylinder theyre set, i replaced mine 18 months back,

 

[vtech]

pull out fuse for abs control unit and see. I hade one problem like that on passat b5. it turned out to be abs! when I scaned it for codes it was clear but still it was faulty

 

[Muttley]

The most likely thing to be putting uncommanded pressure on the caliper is the ABS unit. The master cylinder is spring-loaded in the off position and would in any case affect at least two wheels (from the diagonal split brakes circuits).

Other than that, maybe a warped disc, or the wrong spec of disc (too thick) mounted by mistake?

 

[Allan_84]

when the caliber is binding, try unscrew the air bleed screw at the caliber, if it stil is binding after this then its not a hydraulic issue, and you can forget about brake hoses and master cylinder and the abs unit.

maybe its the caliber carries that is warped

 

[boabym]

Thanks for the replies guys all good advice. The brakes had an almighty cooking a couple of weeks ago so the suggestion of warped disc is one to try. But a warped carrier?is that possible?
How do I check the abs unit? Pull out the fuse or vagcom? I was going to put it into a specialist VAG garage for a pressure bleed and fluid change just to rule that out. Would they activate the abs when they are pressure bleeding?

Sorry for the barrage of questions but I really am at my wits end with this not to mention at the bottom of my wallet!

 

[vtech]

As for checking abs unit just pull out the fuse. If its not the abs just clear the power suply code with vcds.

 

[Wilko]

Had this recently.
Replaced master cylinder, had front calipers rebuilt, new rear calipers.
Eventually replaced servo, and it sorted it. Pull the pedal up with your foot. Do the brakes release. If so, it's servo.

 

[boabym]

Yip the brakes release when I pull the pedal up with my foot. So new servo it is I guess Can you tell me a price for one?

 

[Wilko]

I picked up a used one for 40£.
Fitting is a bitch though. 3-4 hours on a mkiv golf. Access is a bitch

 

[Steely]

http://www.seatcupra.net/forums/showthread.php?t=256313&highlight=hissing+servo

my old thread

 

[boabym]

Cars fixed! Mechanic said there is a threaded bar in the servo which is adjustable. Screwed it in and no more.binding brakes Yippee!