Ate calipers?

[macc nova]

Since putting my 16v brakes on i have noticed that when i first start the car up the brake peddle is solid (its hard to push down)! After ive braked a few times its fine and works as expected! It passed its mot with them on the other day so it cant be anything serious i hope! What do ya reacon it could be?

[Stoo]

its just the servo working

have you pumped the brakes with the engine off?

[meritlover]

maybe it is the pads being cold? what type of paddage are your calipers wearing?

[Stoo]

cold pads wouldnt make the pedal hard mr merit

[meritlover]

i know but i didnt understand what was meant by 'hard pedal' i took it to be it was requireing more effort to give the same braking performance as after they had been used.

[mikey14sr]

Mine used to do the same thing, if you turn off and restart the engine does the servo feel like it's working instantly? mine did and I tracked it down to the unobtainable 1-way valve in the servo hose being fubarred.

[Steve]

My mate had that before, was worse in the cold as when he went down the road and first applied the brakes the pedal was solid and didnt really stop!

After a couple of pumps of the pedal it wnet 'normal' again, never found out what caused it as he sold it but we suspect it was the callipers sticking as after abusing the brakes for a while they would sometimes go hard again.

[macc nova]

Mine used to do the same thing, if you turn off and restart the engine does the servo feel like it's working instantly? mine did and I tracked it down to the unobtainable 1-way valve in the servo hose being fubarred.

yeah its the same thing, after about 3 or 4 pumps of the pedal its fine :thumb: as long as its nothing to worry about.

[craig green]

If the 1 way valve has given up the ghost, change it pronto or you'll be needing a new servo. Not fun!

[meritlover]

why will having a failure NRV break the servo?

[craig green]

Its there to stop fuel vapours from the inlet entering the servo & perishing the diaphragm.

I had to swap my servo 3 times on my 1st Nova, which on 2 occasions meant changing the Master cylinder as I couldnt find matching types at the time. The non return valve is about ?3 from Vaux + some vacuum hose & clips.

[meritlover]

ah yes i see. i thought the diaphragm would have been a butyl rubber or some sort so it is not violated by brake fluid from a failure mastercylinder. but i guess not if your saying so. an NRV at ?3 is a very cheap fix!

[macc nova]

The non return valve is about ?3 from Vaux + some vacuum hose & clips.

Is the non return valve the Pressure regulating valve? And if so do i change both of them?

[meritlover]

it might be referred to as that but im not sure if they refere to it as a PCV. its the one inlines with the sero to the manifold on the plastic pipe.