Car jerkes when break is applied and released

[lahiruchandima]

Hi,

Sometimes when I apply brake in my Toyota Vitz 2007 and release the break, it feels like some invisible brake is still applied. If I do not accelerate after releasing break, the car jerks after some time as if the invisibly applied break is removed. This does not happen every time but some days this happens more frequently.

I thought this could be a transmission problem and changed transmission fluid. At first i thought it solved the problem but issue still exists.

What could be wrong with my car? Your help is highly appreciated

Thanks

[shorod]

Are you referring to the hydraulic brakes or the parking brake?

Does the "some days this happens more frequently" comment seem to have something common, such as "more frequently on rainy days"?

Have you checked brakes after a drive for one that might be getting hotter than the others?

When is the last time the brake system was flushed with fresh fluid? Typically this is recommended every 1-2 years. If you have never had the system flushed, you might have a brake hose that has collapsed internally and is not releasing one of the brake calipers/wheel cylinders freely.

-Rod

[lahiruchandima]

Thank you Rod for the reply.

I'm referring to the hydraulic break.

Actually I think the issue occurs more frequently in rainy days than normal days but there are some days this occurs more frequently even without rain.

I haven't checked whether a break gets hotter than others. I'll check that today.

I have only used the car for about 6 months so I do not know whether break oil has been changed recently. But I don't think the previous owner has changed the oil recently. Anyway, break oil level is OK.

Can you isolate the issue with these info?

Thanks again

[shorod]

I can't necessarily isolate the issue with the provided info, but might be able to refine the searching. If the brake fluid is more coffee color than clear like vegetable oil, you should flush the system and check for any brake pads that are worn more than the others. Look at both the inboard and outboard pads and make sure they are wearing evenly.

Since the issue may be more frequent during rainy days than non-rainy days, the issue if one pad or both pads at one wheel is wearing more than the others would likely be due to the lubrication for the slide pins/bolts of the caliper than due to brake fluid condition and a internally collapsed brake hose.

Does your Vitz have rear drum or rear disc brakes?

-Rod

[lahiruchandima]

Vitz has rear drum brakes.

Also, theres one more thing which I forgot to tell earlier. The front left wheel produces a repeating noise when I brake. Repetition frequency is higher at higher speeds and low at low speeds so I think there is a problem with the disk. But if the brake pads get stuck in front left wheel after I release the brake, shouldn't the car tend to turn to left side when driving?

Thanks

[shorod]

Yes, I would expect the car to pull to the left if the left front brake caliper were not releasing. The noise could be a build up of rust on the rotor or it could be something more serious. It's nearly impossible to determine how serious it is based on a written description of the noise. You might be at a point where you need to take the car to a professional to have them properly diagnose the jerking and the noise. Brakes are a rather critical safety system on the car and there are enough unknowns that the best thing would be to have someone local to you inspect the car.

-Rod

[lahiruchandima]

Thanks a lot Rod for your help. I also think its better to take the car to a professional.