Need to step harder on the pedal to brake after tire change

[karyins]

Got a new set of tires last week. And immediately afterwards I must step harder on the braking pedal to brake as before. Didn't think much of it since I could still brake, and I thought it might be related to the new tires?

But last couple of days I was driving another car and the brake was super responsive. Today I got back to the 4runner and, call me crazy, but I feel that I have to really step on it to make it stop. So it got me concerned.

What might have caused this?

Thanks!

 

[LC2013]

Did you go up in size?

 

[karyins]

Did you go up in size?

Nope, same size.

Just googled this:

"Ask a mechanic to test your brake power boost unit. A faulty brake power boost unit causes the brake pedal to depress more than usual in order to activate the brakes. "

Could tire change damage the brake power boost unit?

 

[LC2013]

Shouldn't....... Have you checked your brake fluid?

 

[karyins]

Shouldn't....... Have you checked your brake fluid?

Checked. It's a little bit over the max line and yellow-brownish.

 

[The Grand Wazoo]

seeing how they messed with your hubs, i would check your wheel bearings. they can cause the pedal to feel soft.:shrug:

 

[karyins]

Just went testing drive a bit. Overall it's still OK. I can still stop fast. No pulling when braking. Brake padel does not go to the floor. When I step down on the pedal the braking power increases gradually.

I just need to step on it a little harder(or perhaps deeper?) to get the same braking power as before the tire change. For example, at the stop sign or in a traffic, before the tire change I just needed to rest my foot on the pedal. Now I need to consciously press down a little to keep the truck from moving.

Any idea?

 

[2014 Warthog]

Just went testing drive a bit. Overall it's still OK. I can still stop fast. No pulling when braking. Brake padel does not go to the floor. When I step down on the pedal the braking power increases gradually.

I just need to step on it a little harder(or perhaps deeper?) to get the same braking power as before the tire change. For example, at the stop sign or in a traffic, before the tire change I just needed to rest my foot on the pedal. Now I need to consciously press down a little to keep the truck from moving.

Any idea?

My 5th gen takes more brake pedal pressure than most other cars and has since new. That's just the way it is. When switching between the runner and any other regular car it's quite noticeable.

But also, even if you stayed the same tire size, you have worn off the tread of the old tires making them smaller in diameter and easier to brake over time. New tires would suddenly make it somewhat harder to brake, not much, but you may be just able to tell because of the sudden change.

Finally, were they the same tire? Different manufacturers actually have slightly different diameters for their tires even at the same size. A combo of the new tread and possibly larger diameter to start probably would be noticeable.

 

[karyins]

My 5th gen takes more brake pedal pressure than most other cars and has since new. That's just the way it is. When switching between the runner and any other regular car it's quite noticeable.

But also, even if you stayed the same tire size, you have worn off the tread of the old tires making them smaller in diameter and easier to brake over time. New tires would suddenly make it somewhat harder to brake, not much, but you may be just able to tell because of the sudden change.

Finally, were they the same tire? Different manufacturers actually have slightly different diameters for their tires even at the same size. A combo of the new tread and possibly larger diameter to start probably would be noticeable.

I think you nailed the problem. Old tires were bridgestone H/T 840D with 4/32" thread and new tires are continental LX20 with 13/32" thread. So a little over half inch bigger in diameter.

 

[CoupeDeGras]

I'm no mechanic so I would get it checked if you are unsure but here's a thought to look in to. If you are experiencing sticking calipers your breaks may have a much stiffer pedal and when they are free it can get much softer but still stop just fine. I didn't notice mine pulling much bc both sides were sticking depressed. When the new ones were in it felt like the pedal went through the floor compared to before.

 

[karyins]

I'm no mechanic so I would get it checked if you are unsure but here's a thought to look in to. If you are experiencing sticking calipers your breaks may have a much stiffer pedal and when they are free it can get much softer but still stop just fine. I didn't notice mine pulling much bc both sides were sticking depressed. When the new ones were in it felt like the pedal went through the floor compared to before.

My pedal isn't stiffer, nor is it softer when free. So it does not seem to be a caliper problem. Other than the new tire, only thing I can think of is bubbles in the braking system. People describe it as "spongy". Does that mean when you step on the pedal it feels soft and not pushing back?

My pedal does not feel soft and the more I step down the more force it's pushing back. It feels like there is lubricant between the braking pad and the rotor and you just need to apply more force to make it stop.