Let's of break pedal pressure needed

L

Lewis&Clark

New member
My '08 T4R has, ever since I bought it two years ago, needed rather heavy pressure on the break pedal in order to remain stopped. Even slightly less than very heavy pressure and the car rolls forward. I just assumed is the way the car was built, but someone today told me otherwise.

Either way, is there anything I can do to make it need a little less pressure?
 
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One thing that will make a difference is if the A/C is on; bumps up the idle a bit and requires more pressure. This includes if def. is on (and maybe floor/def. combo? not sure) as the A/C is on then (even though the A/C light is not lit).
You can put it in neutral when stopped.
Aside from that I can't help you much.
 
It's pretty normal for 4th gens to take a lot of brake to hold at a stop, especially if the A/C is on (as SSt4r said). No great solution for that, sorry.

Turn off A/C
Shift into neutral
Swap to more aggressive brake pads

...that's about it though.
 
I disagree that this is normal, at least until you check a couple of things.

First, be sure the brake booster is getting the proper vacuum to give you the brake assist as designed. If there's a vacuum leak, it may not be boosting as it should.

Second, and much more likely, is that you have a frozen or stuck caliper and the reason for the hard pedal is that the piston in the caliper (or more than one caliper) isn't moving, and the ones that still work have to work twice or three times as hard to stop/hold the truck.

Get your calipers and booster checked before you accept this behavior as "normal".
 
emoore924 said:
I disagree that this is normal, at least until you check a couple of things.

First, be sure the brake booster is getting the proper vacuum to give you the brake assist as designed. If there's a vacuum leak, it may not be boosting as it should.

Second, and much more likely, is that you have a frozen or stuck caliper and the reason for the hard pedal is that the piston in the caliper (or more than one caliper) isn't moving, and the ones that still work have to work twice or three times as hard to stop/hold the truck.

Get your calipers and booster checked before you accept this behavior as "normal".
Click to expand...

The 4th Gen 4Runner produced for the North American market does not utilize a traditional Vacuum Assisted Brake Booster. It utilizes a Hydraulically Assisted Master Cylinder Unit that has an electric pump to pressurize a nitrogen filled accumulator pod to provide assistive force. This system provides a relatively input pressure vs. pedal travel and leads to many people mistakenly believing the system to have a "soft" or "spongey" brake feel. The reality is that the system provides a very consistent pedal stroke with minimal input force variation (i.e. instead of the pedal pressure increasing as you get further to the floor, you can easily push the pedal all the way to the floor with very little increase in over all pressure applied.)

The braking system is designed to be this "easy to operate", but it is a very different feeling than typical vehicles (even some Toyotas that have a different version of the same hydraulically assisted system since they tend to tuned differently), it takes some getting used to. It's very common to under apply the brakes (particularly in the V8's when the A/C is on) and have them "creep" because the pedal pressure is so consistent you can let up a little and not notice right away the brakes aren't "biting" anymore. There's other factors that can add to this such as glazed pads/rotors, seized/seizing calipers, ect. I know my 4Runner's brakes are a bit glazed and don't bite as well as I would like (will rectify that eventually one way or another.)

Bottom line, it's probably normal due to the way the braking system is designed and the low-end torque of the 2UZ-FE in an off-idle situation (i.e. A/C running) if you let off the pedal slightly. There's also the possibility that the brakes are not gripping well enough due to glazing and/or caliper issues; so it doesn't hurt to give them a look anyways.
 
Dont forget that in addition to glazed pads and rotors, that cheapie pads over exact OEM or high performance pads will have less than desirable braking effects.
 
Tooltime19 said:
Dont forget that in addition to glazed pads and rotors, that cheapie pads over exact OEM or high performance pads will have less than desirable braking effects.
Click to expand...

True. In my case, however, my truck is still running the original factory pads even after 115,000 miles. They still look pretty good and I have the break system checked once a year, and all the other parts look good. But I can't help but wonder if aging pads, decently thick and in good shape or not, might make the break pressure problem worse.
 
Lewis&Clark said:
True. In my case, however, my truck is still running the original factory pads even after 115,000 miles. They still look pretty good and I have the break system checked once a year, and all the other parts look good. But I can't help but wonder if aging pads, decently thick and in good shape or not, might make the break pressure problem worse.
Click to expand...

Do you not use the brakes very often? 115k on factory pads is a bit ridiculous, particularly if they are "decently thick." I find that hard to believe, I'm starting to wonder now if there's something else going on...
 
I disagree that this is normal, at least until you check a couple of things.
1c.jpg
 
BlackWorksInc said:
Do you not use the brakes very often? 115k on factory pads is a bit ridiculous, particularly if they are "decently thick." I find that hard to believe, I'm starting to wonder now if there's something else going on...
Click to expand...
115K on original pads? Are you like the Flintstones and use your feet to stop? I've never heard of such miles on OEM pads. Take them out and get the pads and rotors real hot to knock off that thick ol glaze. BUT, please make sure you do a proper cool down for an extended period before putting the car away with hot rotors and pads or your next post is going to be one of you calling me bad names for warping your rotors lol. But seriously, that will do the trick.
 
And dont forget to perform a brake fluid flush while you are at it. I flush my system every couple of years, or more depending on situations.
 
BlackWorksInc said:
Do you not use the brakes very often? 115k on factory pads is a bit ridiculous, particularly if they are "decently thick." I find that hard to believe, I'm starting to wonder now if there's something else going on...
Click to expand...

I can't explain it either. Never have I had OEM brakes run this long. I've heard the T4R uses the heavy duty brakes of the Tundra, but still, this passes any form of human understanding.

I posted a thread about this several months back to see if I was the only one. Turns out I'm not -- some others posted to say they'd had incredibly high runs with their factory OEM brakes too.

I do, however, wonder if there's something else going on too...
 
Tooltime19 said:
115K on original pads? Are you like the Flintstones and use your feet to stop? I've never heard of such miles on OEM pads. Take them out and get the pads and rotors real hot to knock off that thick ol glaze. BUT, please make sure you do a proper cool down for an extended period before putting the car away with hot rotors and pads or your next post is going to be one of you calling me bad names for warping your rotors lol. But seriously, that will do the trick.
Click to expand...

LOL. Seriously, I can't explain the pads. I'm not exactly a lightfoot either.

The rotors need to be resurfaced or replaced. Since the car is going on eight years old, I'm inclined to just replace them. They're not urgent, and three different mechanics including a Toyota dealer have all said as much. You can sometimes feel a slight shudder.

They'll probably be replaced in the next few months. I'm inclined to replace the pads too, even though I've been told by the same three dealers that I can probably go a little while longer without replacing them.
 
Here's the original thread about the insanity of my brake pads. That was last June, when they were measuring about 7/32 all around.

My most recent check (November / early December?) had them at 5/32 all around.
 
BlackWorksInc said:
The 4th Gen 4Runner produced for the North American market does not utilize a traditional Vacuum Assisted Brake Booster. It utilizes a Hydraulically Assisted Master Cylinder Unit that has an electric pump to pressurize a nitrogen filled accumulator pod to provide assistive force. This system provides a relatively input pressure vs. pedal travel and leads to many people mistakenly believing the system to have a "soft" or "spongey" brake feel. The reality is that the system provides a very consistent pedal stroke with minimal input force variation (i.e. instead of the pedal pressure increasing as you get further to the floor, you can easily push the pedal all the way to the floor with very little increase in over all pressure applied.)

The braking system is designed to be this "easy to operate", but it is a very different feeling than typical vehicles (even some Toyotas that have a different version of the same hydraulically assisted system since they tend to tuned differently), it takes some getting used to. It's very common to under apply the brakes (particularly in the V8's when the A/C is on) and have them "creep" because the pedal pressure is so consistent you can let up a little and not notice right away the brakes aren't "biting" anymore. There's other factors that can add to this such as glazed pads/rotors, seized/seizing calipers, ect. I know my 4Runner's brakes are a bit glazed and don't bite as well as I would like (will rectify that eventually one way or another.)

Bottom line, it's probably normal due to the way the braking system is designed and the low-end torque of the 2UZ-FE in an off-idle situation (i.e. A/C running) if you let off the pedal slightly. There's also the possibility that the brakes are not gripping well enough due to glazing and/or caliper issues; so it doesn't hurt to give them a look anyways.
Click to expand...

You know if FJ Cruiser is also set up in the same way?
 
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