Brake Pedal Suction Noise?

MaddoxPics

MaddoxPics

New member
Looking for a little help on this, and hoping I didn't screw up anything serious.

Did my brakes yesterday. Changed both the rotors and pads. I admittedly have never done this before, however read and watched a ton of videos to where I am certain I did everything correctly.

Jacked up vehicle, sat on jack stands. Removed brake line bolt to allow for more flex. Put the caliber that I was working on on a jack stand. Used old brake pads to compress the caliper piston. Grease on the back of the shims. Put back together. Factory torque specs. Done.

Pumped the brakes multiple times after finishing and they will not stop going to the floor. Thought maybe it was because the vehicle wasn't on (being it's an electric motor). Did the same, same results. Drove around block, it slowed down, but very slowly.

When I got back I could tell there was a distinct suction noise coming from the pedal area after I would release.

Trying to figure out what my issue could be?

I don't see how the brake booster or master cylinder would have gone out from a brake change? But maybe I'm wrong?

Air in lines? But I didn't bleed brakes or remove the nipple so not sure how that would happen without a crack in the line. And I am experiencing zero leaks anywhere.

Any tips or possibilities of where I may have gone wrong? I have a trip next week so trying to pinpoint stuff before I take it to a shop (assuming it's a simple fix).

Brake fluid is also level so don't see it being low on fluid.
 
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I'm a noob, and I recently bought a 2019 with 21k miles. Mine makes that swoosh sound as well when releasing the brake pedal.
As long as the brake pedal isn't squishy, and brakes are actually engaging, it may be nothing but a heightened perception and increased attention to the brakes that you just worked on.
 
awaywego said:
I'm a noob, and I recently bought a 2019 with 21k miles. Mine makes that swoosh sound as well when releasing the brake pedal.
As long as the brake pedal isn't squishy, and brakes are actually engaging, it may be nothing but a heightened perception and increased attention to the brakes that you just worked on.
Click to expand...

It's definitely not normal. It goes to the floor, and when test driving it stops, but takes much longer to. I keep being told by auto buddies to bleed the brakes because air is likely in the lines. This could be true, but not sure why this issue wouldn't have happened before doing the brakes if that was the culprit.
 
jp.vegas said:
You should bleed brakes after a pad change. Try that.
Click to expand...

That's my next plan. I assume I'd have a code if it were a booster or cylinder going out/out. I did a bunch of long pumps earlier with the vehicle off and it brought back some pressure, which makes me suspect it is air.
 
I fail to see how you've damaged anything assuming you're not seeing brake fluid leaking. Changing pads and rotors is crazy easy and really difficult to screw up. If you screw it up, usually things don't back together correctly and/or you get lots of noise and the wheel likely won't move freely.

Toyota brake pedals have total crap initial feel. I've noticed this in all Toyota rentals I've had and my wife's 2020 4runner is the same. It always takes me a few minutes to adjust to the 4runner's pedal when coming from my BMW M235 or Outback 3.6R. When you initially depress the brake pedal on the 4runner, there is a hiss/suction/swoosh noise as the pedal travels 1/2" before I feel any real meaningful bite from the brakes. This goes for every Camry, Avalon, RAV4, Venza, etc. I've rented in the last decade (and there have been many).

I think the sound you're hearing is normal; you've just now paid attention to it because you had never changed pads/rotors and and you're worried you did something wrong.

There is absolutely no reason to flush the brake fluid on a rotor and pad change. There's also NO possibility of air getting into the lines during a pad/rotor replacement assuming you didn't open the bleeders or let brake reservoir was super low or slice/break a line.

As for weak brakes, the likely issue is the rotors and pads need some bedding. When you replace pads and rotors, brake feel on the first drive can be scary. Brakes really come to life after you do a few hard braking events. I'd do 3 to 5 50mph to 10 mph back to back near stops and then drive to cool off the brakes. You'll be surprised by the increase in bite and feel once they are bedded.

Did you clean the rotors with brake cleaners or some other solvent before installing? The rotors have a rust inhibitor that should be removed before install. If you don't remove it, it can make braking real sketchy and weak. The inhibitor can get into pad and will take a long while to burn off. Again, you'll need to do some hard braking to get them really hot burn the stuff off.
 
you always bleed every brake pad change. when pushing the piston back, you also need to open the bleeder in the caliper and open the cover from the reservoir. that way, the fluid has a place to evacuate. if you did not do that, you might experience hard to push piston.

bleed it first and make sure to bleed all wheels and make sure the reservoir is always full, not going too low during the bleeding.
 
I agree with CharlesBronson above. Been changing my pads the way you did for the past 30 years. Also replaced rotors on my runner the same way.

Is there a chance you loosened a bleeder screw or left the cap open on the reservoir?
 
1. When you push the caliper pistons back, the fluid behind them goes back to the master cylinder reservoir, so it can over flow. You have to expect that. Usually you need to suck some of the fluid out before compressing the pistons.
2. After the new pads are in place, it can take a lot of fluid to push them back against the disk. Thus, you may run out of fluid in the master cylinder, which will put air in the lines.
3. As others have said, you always need to bleed the system to get rid of that air.
4. Since brake fluid is hydroscopic (absorbs moisture from the air) it is recommended that you do a brake fluid flush every two years. When you change brake pads is a good time to do that. If there is too much moisture in the brake fluid, it will turn to vapor when the brakes get very hot. Vapor acts like air and you will have lost your brakes. Moisture in the brake fluid can also cause rust inside the metal brake lines.
 
Last edited:
MaddoxPics said:
Looking for a little help on this, and hoping I didn't screw up anything serious.

Did my brakes yesterday. Changed both the rotors and pads. I admittedly have never done this before, however read and watched a ton of videos to where I am certain I did everything correctly.

Jacked up vehicle, sat on jack stands. Removed brake line bolt to allow for more flex. Put the caliber that I was working on on a jack stand. Used old brake pads to compress the caliper piston. Grease on the back of the shims. Put back together. Factory torque specs. Done.

Pumped the brakes multiple times after finishing and they will not stop going to the floor. Thought maybe it was because the vehicle wasn't on (being it's an electric motor). Did the same, same results. Drove around block, it slowed down, but very slowly.

When I got back I could tell there was a distinct suction noise coming from the pedal area after I would release.

Trying to figure out what my issue could be?

I don't see how the brake booster or master cylinder would have gone out from a brake change? But maybe I'm wrong?

Air in lines? But I didn't bleed brakes or remove the nipple so not sure how that would happen without a crack in the line. And I am experiencing zero leaks anywhere.

Any tips or possibilities of where I may have gone wrong? I have a trip next week so trying to pinpoint stuff before I take it to a shop (assuming it's a simple fix).

Brake fluid is also level so don't see it being low on fluid.
Click to expand...

My gm cars made that suction noise, my dodge ram makes the suction noise, my 4runner makes the exact same noise and is way more noticeable when it's cold out once the cabin warms up it goes quiet


I really don't think you need anything up and Toyota brakes are mushy compared to other brands, but I like the ABS better than all of them I prefer the clicking as compared to the pulsing
 
The sytem is sealed like others have mentioned so air shouldnt be in the system. On the other hand if you already had air in the system before your brake job then you must bleed the system. After doing the brake pads pump the pedal to push the pads against the rotor and then bed the pads into the rotors. A few stops from 45mph. Also quick slow downs from 60 to 45 mph.
 
4r-4ever said:
you always bleed every brake pad change. when pushing the piston back, you also need to open the bleeder in the caliper and open the cover from the reservoir. that way, the fluid has a place to evacuate. if you did not do that, you might experience hard to push piston.

bleed it first and make sure to bleed all wheels and make sure the reservoir is always full, not going too low during the bleeding.
Click to expand...

Huh? I've probably changed 100 sets of pads on my cars and friends cars over the last 30 years and this includes swapping pads for race days too and I've never changed the fluid during this work. When my BMW was under it's free maintenance, BMW didn't change the fluid when they replaced my front pads and rotors.

You should open the brake reservoir on a pad change, but there's absolutely no need to open the bleeder and would never recommend it. If you open the bleeder while pushing in the piston, you'll certainly get air in the system which will be a monumental pain to clear out Yikes
 
So I never opened the reservoir cap while doing the brake change. Is that looking to be my culprit? Am I going to need to just completely flush the brake lines? It's never been done before so I'm guessing it's not a horrible idea?
 
Jivewalker said:
I agree with CharlesBronson above. Been changing my pads the way you did for the past 30 years. Also replaced rotors on my runner the same way.

Is there a chance you loosened a bleeder screw or left the cap open on the reservoir?
Click to expand...

Nope. Only brake line screw I did anything to was the one attached to the spindle so it wouldn't have a lot of stress on the line. Cap on the reservoir was closed, but some saying I should have had it open?

fkheath said:
4. Since brake fluid is hydroscopic (absorbs moisture from the air) it is recommended that you do a brake fluid flush every two years. When you change brake pads is a good time to do that. If there is too much moisture in the brake fluid, it will turn to vapor when the brakes get very hot. Vapor acts like air and you will have lost your brakes. Moisture in the brake fluid can also cause rust inside the metal brake lines.
Click to expand...

I'm long overdue for that anyways so hopefully this is the issue and I haven't caused any damage anywhere else.

Tbasse01 said:
I really don't think you need anything up and Toyota brakes are mushy compared to other brands, but I like the ABS better than all of them I prefer the clicking as compared to the pulsing
Click to expand...

Good to know on noise, but I can tell you the pedal is going way too low and not having enough resistance when being pressed. Something isn't right.


spartacus said:
The sytem is sealed like others have mentioned so air shouldnt be in the system. On the other hand if you already had air in the system before your brake job then you must bleed the system. After doing the brake pads pump the pedal to push the pads against the rotor and then bed the pads into the rotors. A few stops from 45mph. Also quick slow downs from 60 to 45 mph.
Click to expand...

I did the latter stuff, and similiar to it. The only thing I do know is I had rear brake lines put in, so perhaps air got in during that time.
 
MaddoxPics said:
So I never opened the reservoir cap while doing the brake change. Is that looking to be my culprit? Am I going to need to just completely flush the brake lines? It's never been done before so I'm guessing it's not a horrible idea?
Click to expand...

Opening the cap reduces the effort of pushing the brake pistons back. Though not ideal, pad replacements can be done with the cap on, it just takes a bit more effort and the pistons are slower to push back. The cap is not air tight, hence the reason brake fluid takes on moisture over time. I can't see why not opening the cap would be the cause for any of your problems.

Is the truck driveable? You make it sound like you have no brakes. If the truck has brakes, then check the reservoir fluid level to make sure it is at the correct level. Then carefully drive to a secluded area or long parking lot and do some panic braking as I noted above to get the pads and rotors bedded and see if the brake come to life.

What brand pads and rotors did you use?
 
[QUOTE
The only thing I do know is I had rear brake lines put in, so perhaps air got in during that time.[/QUOTE]

If they didn't bleed the brakes or did a subpar bleed after installing the lines then that would be the culprit.
 
spartacus said:
[QUOTE
The only thing I do know is I had rear brake lines put in, so perhaps air got in during that time.
Click to expand...

If they didn't bleed the brakes or did a subpar bleed after installing the lines then that would be the culprit.[/QUOTE]

I would think braking would have been crap prior to the pad and rotor replacement if there was already air in the lines.
 
Charles Bronson said:
Is the truck driveable? You make it sound like you have no brakes. If the truck has brakes, then check the reservoir fluid level to make sure it is at the correct level. Then carefully drive to a secluded area or long parking lot and do some panic braking as I noted above to get the pads and rotors bedded and see if the brake come to life.

What brand pads and rotors did you use?
Click to expand...

Yes I can drive it, but I wouldn't want to go over 40 in fear of not being able to stop in time if something were to happen. Even at 40 I'd probably stay further back because it takes longer than normal.

Reservoir is still at full. I'll find a lot tonight and test out what you think can work.

I went with Remmen Brakes.
 
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