Plenumotron
 

Hi all
Another question, why does my brake pedal now feel wierd when i go from accellerating hard to braking, i mena it feels like its been pressurised with air, and theres like a balloon have to crush before the brakes work, is quite scary at 120 mph

It happened when i changed the cracked leaky tube from the plenum chmaber to the servo assist beastie

Keeping it fresh for 2007

are you talking about the hose that goes from the upper intake manifold to the brake booster?

That hose has a check valve built in so the brake booster only gets vacuum. If you replaced it with a non-Mazda part, you probably eliminated the check valve.

In the US, there was a recall done on that hose which moved the check valve and changed the design. If you have a RHD car, that's a whole 'nuther story, I'm not sure where to source that check valve.

Regardless, you need to get that fixed pronto - that's a BIG safety problem.

Dale

Correct, or the check valve could be faulty, or the vacuum assist chamber or hose could have a leak. You are feeling either no vacuum assist or positive manifold pressure (resistance instead of assist) until the manifold vacuum builds up and assists braking again.

Dave

Yes I am, the bit i removed looks just like a piece of pipe, are you saying there is a concealed valve in here? What should i do?

Replace it with the factory part.

Legend

The sleeve