Brake Pedal Hard On Start Up.

[mrmungy]

I have a C5 2.0HD exclusive on 03 plate

 

I have just had the Head Gasket done.

I got the car back on Monday

Yesterday Morning, the brake pedal was as hard as a rock when first started the car up, then after a short while (less than 30 seconds) the brake pedal was functional.

 

The same happened when I left work in the late afternoon and again this morning (Friday)

 

From what I can see the vacuum pipe is bolted on tightly

 

Has anybody ever had this problem either after having a head gasket done or otherwise.

 

Thanks

[mflynn1971]

This used to happen to me in the wet(pretty scary) when on the move in a 2002 406 with very similar engine set-up though I think this is probably a different problem.

If anything affects your vacuum in brake booster this can happen. Its a long time since I worked on it but i rememberer there is a check(one way) valve  to maintain vacuum in the booster while engine is off and for repeated braking. If this valve starts leaking you will notice a hard pedal for a while after starting. Its simple to replace . 30 secs seems long though for vacuum recovery. From memory it was easy to pull it out. If you suck on it from booster side nothing should come through.. 

hope this helps...

Mike

Edited April 17, 2015 by mflynn1971

[coastline taxis]

sound advice from mflynn.  Have u checked all pipes for security/leaks//splits

[mrmungy]

Thanks for the advice, I will be seeing what the mechanic does when he comes back to me and maybe show him this message.

[Landmark]

Hi, In addition to the advice above, a quick check to see if the servo is working is, with the engine OFF, press the brake pedal several times to exahust the vacum.Then, with foot still on pedal, start the engine and you should feel the pedal go down slightly.

Griff

[paul.h]

The vacuum pump may have been removed when doing the head gasket so check if this is fitted properly, it is not rattling, if the hoses to it are fastened and not damaged or full of oil and its seal is still in good condition. Normally the vacuum would remain in the servo overnight so for some reason it is leaking air in - you may even hear air being sucked in somewhere with the engine running or just after stopping it to remove the engine noise.