Too much Brakes

Over the weekend I did the following:

1. Replaced both strut assemblies, both leaking
2. Replaced drivers side inner and outer tire rods due to slop in both of them
3. Replaced sway bar end links on both sides, both worn with slop in them

Here’s the question on the brakes; I’ve noticed the last several times that my truck has sit for a couple days without driving the first couple of times I hit the brakes they almost throw me through the windshield. After they are engaged 4 or 5 times they are fine.

Any ideas on what may be causing this appreciated.

Thanks in advance,
Griff04

 

Could the brakes be developing just a little bit of corrosion from sitting? On my mom's car the brakes are a lot louder for the first few applications after it sits, but that's really only if it's been a week or more, or if it's rained.

Also- this started after you replaced the struts, tie rods, and end links? Or was it happening before?

 

It’s always been like this, even before the weekend work.

 

Never heard of a temporary overly sensitive brake issue. That’s typically not an issue for our trucks. That said, I’m not sure what’s causing it.

 

I find the same, I just can't remember if they're soft at first, then normal, or firm first, then normal.

I want to say it's firm first, then normal. Maybe it's just a later-year thing?

 

I have the same thing although not as noticeable and it's worse after any kind of rain or snow. I like @FiatRunner explanation, makes sense to me.

 

I'm not sure how helpful this information is, but I figured it was worth noting-

The brake calipers on my little Fiat 124 don't slide very well, and after the car sits for a week or two, it takes a couple good stabs at the brake pedal to get them loose. The brakes will drag and the pedal will be touchier. I think this is similar to the light corrosion idea, maybe things just need to loosen up a bit?

Do you know when was the last time the brakes were replaced? Are they in good condition?

 

Your Fiat brakes are little different design than the Tundra brakes. Fiat has (from my google search) a single piston with sliding caliper pins. The sliding caliper pins are what I believe you are refereeing to sticking a bit at first.

The Tundra has 4 piston calipers, 2 on each side. Because there are pistons on both sides there is no need to have it on sliding caliper pins. As such, it is rigidly mounted to the knuckle. No sliding pins to stick.

I am 100% with you on slight corrosion after sitting creating this increased braking feel. I've experienced it many times on multiple vehicles. Though surprisingly enough I don't experience it much on my Sequoia.

 

Man, you're completely right. For some reason I pictured the caliper with slide pins, despite having pistons on both sides. Total brain fart moment.

I think it could still apply though- it sounds to me like something is sticking or not working as smoothly after sitting.

 

It’s definitely not a show stopper for sure, just thought it was a little odd. Maybe it’s just the corrosion thing that Fiat mentioned.

thanks for the replies.

 

The T100 had 4 piston with sliding pins, probably other toyotas of the same era

 

Got a picture of one? I'd be interested to see how it's set up.

All I can find are single piston with sliding pins (2WD), and 4 piston with no pins/solid mounted (4WD).

 

Had a similar issue in mine - turns out one of the calipers was sticking. Not so bad that it dragged, but you could feel it if you lifted the front wheel off the ground and tried to spin it after the truck sat for a few days. Determined it was a good time to just upgrade the brakes to WLs and bought calipers, rotors, pads.

 

Richid, stupid question here, what does the acronym “WLs” stand for in your reply?

 

I can answer. WL is the last two letters of the brake caliper model. WL, WE, WG are common brake caliper suffixes for the year rangle SUV/Truck these are.

Earlier models of 1GT I think are all 13WE. My 2006 have 13WL calipers as should yours. I might have this a bit off, but you get the gist. The caliper model number is embossed on the caliper, same side as the hard brake line.

 

Thanks Shifty.

 

Yes - I think there are some threads around here on this. Early 00-22 came with WE, after used the larger WL. They are direct replacements and there was a TSB for user complaints regarding WE brakes where the dealer would upgrade to WL. They are direct fit, but larger - so swapping requires rotors, calipers, and pads.

Not sure the difference is that much, but I figured to upgrade as soon as I needed a part - so the stuck caliper motivated me.

 

Now that I re-read your comment maybe I misunderstood. The T100 had pins that hold the brake pads in place and the pads slide along the pins as the pads get worn. Not sliding pins like a single sided caliper.

In my awesome paint picture the red is where the pins go.

 

Think rotors are the same but the pad surface is physically bigger right?

 

That’s correct.

 

This is the frozen piston problem. Mine was always the drivers side outside lower. Replaced it twice. Current caliper has held up for the last few years without freezing up. But now when I rotate my tires I take some channel locks and squeeze them all to check them.

 

You have to burn through half the pad before the surface area is bigger. & even then, its not by much.


When i was first going down this rabbit hole i was seeing that 13we rotors were 199mm & 13wl were 231mm, but that doesnt seem to be the case?

 

The rotors appear the same, but pads are apparently .6" longer - I think you can get tapered pads from different vendors. Ya - they would have less surface area until worn down.

Realistically, I got way more brake out of adjusting the LSPV arm and the rear brakes. Of course, I had to replace the adjuster and clean the bell cranks to get everything working back there.

Like @KNABORES, my drivers side caliper had been the problem. Haven't seen it with the WL, but I'm not expecting it to be the resolution.

 

My WE OEs did it first. I replaced everything up front with the upgraded WL, rotors, calipers and new pads. 12k miles later the same thing happened. Replaced the driver's caliper again, and about 20k later, it did it again. Damn. Replaced again and haven't had the issue since (about 30k miles on current caliper). These are not OE calipers, but maybe remans of OE. I've been using the channel lock pliers to move all the pistons (squeezing the frame of the pads on each side to compress slightly) at each tire rotation.

 

Those are caliper length dimensions, not rotors. 13WE and 13 WL rotors are the same, 319mm diameter.

Looks like friction coefficient is the same on both pads (FF), caliper pistons are the same diameter on WE and WL, pad height is the same, and pad length is slightly longer on WL's. Honestly surprised it makes much of a difference.

Edit: though the friction coefficient is a range. F is 0.35 to 0.45 so the WE pads could be closer to 0.35 and WLs closer to 0.45....

 

Oh - great idea! I think I'll start doing this as well as it drags just enough to hang up and not return all the way.

 

Not the case anymore if you go with the generic Toyota OEM ceramic replacements I just did. They got rid of that bevel you see.

 

So I finally got around to pulling the tires and checking for a sticking caliper…bingo, passenger side is definitely the culprit.

Plans are to replace both sides to include rotors, pads, and calipers.

Any recommendations on where to purchase just “stock” parts for this along with manufacturers. I’m really not looking to upgrade anything, the stock brakes work fine for me.

TIA,
Griff04

 

If you're OEM just rebuild. Unless this looks too complicated (it's pretty easy, take your time, have fun). This is your EXACT caliper, so all details are accurate to what you'll do:

https://www.youtube.com/watch?v=qoQlAW4DPnA​

 

Thanks Shifty, the video was definitely worth watching…pretty straightforward, I think I can handle that.