Why does my Maruti Jimny's brake pedal stiffen after I park the SUV

I would have been ok if the pedal felt hard to press after 2-3 days of inactivity. But in my case, the pedal goes hard in less than an hour of parking the car.

BHPian dr_TJ recently shared this with other enthusiasts.

So, I took delivery of a Jimny Alpha AT on 2nd of July. Owing to discounts on MY2023 Jimnys. Mine is September 2023 Manufactured.

PDI was done. But my bad, I couldn't detect the problems that I am facing now.

So, the Jimny brake pedal goes hard after the car is parked and the engine is switched off.

I know that once the engine is switched off, with no active vacuum generation from the intake, the car brake booster will eventually run out of vacuum or if we pump the brake pedal 3-4 times with the engine switched off. Then the brake pedal goes hard.

But in my case, the brake pedal goes hard after I park my car, switch off the engine. I have not touched the brake pedal after the engine was switched off. I would have been ok if the pedal went hard to press after 2-3 days of inactivity. But in my case, the pedal goes hard in less than an hour of parking the car.

Once I press the hard brake pedal and start the engine. The brake pedal depresses and works like normal. Although I feel the braking happens with the pedal pressed 80-90%. Stopping power feels good but not much of stopping power is felt with just a slight press of the brakes. Maybe this is normal, I am not sure.

But the brake pedal going hard in under 1 hour of inactivity is not normal for sure. I suspect a faulty check valve or a failing brake booster. Also. I don't stay in some high altitude location so thin atmosphere and so less vacuum can't be blamed.

I have been driving the car since the weekend only. At first, I thought I might be overthinking or might have made a mistake but no, sadly, it has this problem.

Now, the second issue is the wheel alignment. The car has a left pull. With the steering at the center, the car just fails to go straight. It pulls to the left. I thought this might be because of the slant of our road from the divider to the left of the road but on a flat road, I do find the steering wheel not pointing straight when I Intend to go straight albeit to a lesser degree.

I will send my car to Nexa service tomorrow. Will update here.

Any other BHPian facing a similar issue?

Here's what BHPian Bsilver had to say about the matter:

I don't get what is the problem here with the vehicle. If it is not showing any signs of any failure when the engine is running and is functioning properly then there is no need to worry about it.

The pedal going hard is normal in all vehicles unless there is a fault with the braking system or non-functional pedal assist at engine running, then you may need to look into it, until then why bother if functioning properly?

A proper alignment and road force balancing can fix the issue with the car pulling to the left, if after doing this, it continues to pull in any direction then you need to look into the steering track rods, suspension etc. But try to get the basics correct in the first place to eliminate any other issues.

Happy Motoring!

Here's what BHPian saket77 had to say about the matter:

• Check valve vacuum pipe.
• Leakage from brake booster.

I can think of these two. Please update us when you get a diagnosis done.

Here's what BHPian nova.19_exe had to say about the matter:

Okay, I don't see a problem with this. My dad's 2004 Elantra GT also has this phenomenon!

When I asked my dad about this, he said it's due to ABS, IIRC.

It's not a big deal. This is normal behavior.

Here's what BHPian NomadSK had to say about the matter:

This is quite normal in my opinion. Power brakes use vacuum power from the engine's RPM to multiply the force applied to the brake pedal.

As soon as the engine is switched off, the pedal would get hard immediately with no vacuum power.

During engine running, Only If the brake booster fails or if there is a vacuum leak, it will not work properly, resulting in a hard brake pedal. Even if it fails, you will still be able to brake, but only with your own physical strength, although that's very unsafe to do so.

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