Power Steering Failure: Causes & Solutions

Hello, unfortunately, the brake assist system on my Mazda 6 diesel completely fails when the engine is warm and I brake with the clutch pedal depressed, meaning the engine is then in a low RPM range. When braking without the clutch pedal, everything is fine, and also when the engine is not yet warm. There could be several causes for this, so do you have any tips?
It could be the brake booster, the hoses, or the vacuum pump. How can I rule out any of these possibilities?
When heated, all materials expand, which could potentially cause a leak.
Please help me understand how I should proceed.


Best regards,
Martin.

Hello Martin,

I took the liberty of removing some unnecessary question marks from your post.
I don't know your car, but it's likely that the power brake booster works normally using vacuum.

A slightly thicker vacuum hose runs from the brake booster to a vacuum pump on the engine. This hose may, for example, have been gnawed on by a rodent, and depending on the material, it may also be partially made of stiffer, brittle plastic components.

Of course, the vacuum pump itself could also be defective.

If other components, such as those for EGR (Exhaust Gas Recirculation) or turbocharger boost pressure control, are operated via vacuum, the hoses and connectors associated with these systems must also be inspected.

Best regards, Rainer.

This is my first diesel car, and unfortunately, I don't know how it would manifest if the EGR system or the turbocharger were not properly supplied with vacuum pressure from the vacuum pump.
Perhaps you can help me with that?