Rough Running Engine and rock hard brake pedal

[pdockley]

We have had our Grand Carnival 2006 for just over 3 months its done about 6000 Km.

About 4 weeks ago the brake pedal would start becoming rock hard and then the engine would run really rough almost like a vacuum issue or something wrong internally in the engine.

Our dealer has had the car for 3 days and have said they have been as yet unable to reproduce although they are still trying.

Has anyone else experienced a similar problem and if so what was the root cause and how was it fixed

We really want our car back, i couldnt rave enough about how great we think the car is so this problem is disappointing

[ron1004]

The brake pedal going hard is a sure sign that it's lost vacuum.

I suggest checking the vacuum pipes from the inlet manifold to the brake booster and confirm that the check valve (non return valve) in this vacuum line is working properly.

If possible get a vacuum guage fittted, in just temporary, and monitor this - you can always use the vacuum guage later to guide you in driving economically.

[cpapashley]

Originally Posted by ron1004

The brake pedal going hard is a sure sign that it's lost vacuum.

I suggest checking the vacuum pipes from the inlet manifold to the brake booster and confirm that the check valve (non return valve) in this vacuum line is working properly.

If possible get a vacuum guage fittted, in just temporary, and monitor this - you can always use the vacuum guage later to guide you in driving economically.

I know that there are various tests you can do to isolate what seems to be a vacuum problem in the brake boosting system. Is the dealership having problems repeating the problem?

[pdockley]

After nearly a week of the dealer having the car the problem has been reproduced.

After much debate it looks like the problem is a master brake cylinder. But as usual there are none in the country.

Looks like we are without the car for another week at least. Total of 3 weeks off the road.