2002 Tacoma Brake Sensitivity

[yodta]

Hey fellas,
just picked up a used '02 Tacoma and have a question about brake sensitivity.

I'm coming from an '87 4wd pickup, which is clunkier and the brakes have a more "mechanical" feel - more pedal travel, less boost than the '02, etc.

My question is, where in the pedal travel do you guys find that your truck begins to brake?

on the '02 I have, it requires very little pressure to bring the truck to a stop, basically seeming like an alarmingly super sensitive pedal to me.

Is this normal? I would imagine it's great for carrying loads or towing, but it's unlike any other vehicle I've driven.


I'm pretty sure none of the hydraulics are seized at this point; I'm not finding any drag at any of the wheels.

Booster checks out good.

Comments/ideas?

 

[liljlandon]

Trade? Mine feels soft and rather wimpy. Especially compared to my 84 with the LC brake upgrade.

 

[yodta]

does yours have ABS?
mine doesn't.

ever tried the Harbor Freight vacuum bleeder? works great for pulling fluid through the system. fixed the squishy brakes on my '87.

 

[adventureamericas]

wish i had the same problem. my brakes suck.

 

[liljlandon]

Nope. Non abs.

I purchased one from oreillys, only way to bleed the 40 Chevy we have effectively.

I may need a good bleed, its often overlooked.

 

[yodta]

wish i had the same problem. my brakes suck.

what do yours feel like? squishy, or just relatively slow to brake?

Nope. Non abs.
I purchased one from oreillys, only way to bleed the 40 Chevy we have effectively.
I may need a good bleed, its often overlooked.

Yes, it is. as is frozen hydraulic components. I've had it happen to me on my older truck, usually if sitting for a while and with remanned components. looking back, I've found that I didn't notice it happening because it was so slow, but when it worsened, I smelled the burning brake, the wheel was hot, and it pulled to one side when braking. once I replaced the bad caliper, I then realized that my pedal was hard before, too

====================================

do you guys have much pedal play before the braking begins? mine has no "dead" area. like right off the pedal seat it begins to brake significantly. I checked out all the rear hydraulics manually yesterday, just as a longshot and to cover my bases. they move manually, so not seized. then vacuum bled the system, again, just to rule out basics. same. scratching my head on this. the only thing I can think of now, are possibly incorrect adjustment of the booster pushrod, which requires two Toyota SSTs to check and adjust. I always try to rule out the simple stuff first. this is definitely one of the weirder problems I've ever come across, but you figure all this stuff is set properly from the factory, or properly maintained along the way. one of those is not true, just which?

if this is the case, and it ever was properly set up, I would think that at some point along the way, either this thing got the incorrect master cylinder installed, and that it's got preload on the master cylinder piston. or, the booster was replaced and the rod not properly set, if that's required of a replacement unit. that or it's the wrong one. maybe either/or the booster/master cylinder are different for the ABS model, and mine's non-ABS.

thanks fellas, appreciate the input so far.

http://i125.photobucket.com/albums/p47/msgvb/car-truck/Screenshot2012-06-10at93107AM.png

 

[yodta]

another thing I thought of as a way to check for preload on the master cylinder was to loosen the mount nuts to see whether it popped forward. I did that real quick earlier, and it did not significantly move. I even wiggled it some to see how much tension was on the component due to the hydraulic lines. some. this is not a conclusive check, I understand, as the force required to over come the hydraulic lines tension and resistance of the master cylinder on the mounting studs could be greater than that required to move the master cylinder piston through some range of initial travel.

I'm gonna schedule an appointment at the dealership and try to get some feedback from the service guys.

all of these questions are based on my A$$umption that the brakes are incorrectly set up, that this pedal feel is not normal for this model truck. it could very well be that this is the way they're designed. I'm just not used to this and no other vehicle I've ever driven had brakes this tight, responsive, and effective, old or new.


will post back when I have more information.

 

[liljlandon]

So I bled my brakes today. Very little air in the system, still sucking.

I have no braking until the pedal is 25% depressed or so. Then it acts like normal, until the end. Where it would lock up before is just a gradual stop.

Pads/shoes are new within 6k, booster passed tests. Meh, ready to do the big brake up grade.

 

[yodta]

are you bleeding furthest to nearest?
are you using your vacuum bleeder?

I had my Dad help me bleed the system on my older truck a week or so ago because I was having exactly the same issue you were talking about, only we used the "pump up the brakes, bleed, repeat" method. it was okay for a day or two, but then got sucky again. I just this past week vacuum bled the system and now it's got a good firm pedal that starts after a little free play at the upper range, and will lock the wheels up no problem.

I was concerned that the vacuum tubing I was using wasn't creating a good enough seal, so I went to the hardware store and got some smaller inner diameter stuff that fits more snugly around the bleeder screw. I get everything connected and apply vacuum to the brake bleeder kit and make sure that vacuum holds relatively well before I open the bleeder port.

I pull some fluid down for a bit, then close it all off, and go check the reservoir to make sure I'm not going empty.

try it again. it took me two runs to do mine to the point where the pedal's staying.

if none of this works, you may consider "bench bleeding" your master cylinder. I'm sure you know this, but you don't need to remove it for this; just disconnect the output lines, cover with a thick rag or towel to catch the fluid, have someone slowly depress the brake pedal, cover the holes, release. repeat 3 or 4 times. replace the lines, then bleed the system.

I swear I would have run mine empty a couple of times while vacuum bleeding, and that simply vacuum bleeding until I got fresh fluid out of the system pulled all the air out.

 

[yodta]

I just test drove another 2002 quickly a little bit earlier. It's an automatic, but otherwise the same; no ABS, etc. Brake pedal feels normal in that vehicle, so now at least that confirms that what I'm experiencing is not normal for this vehicle.

Been on justanswer.com earlier with a couple of Toyota pros, and have a couple of things to try. The best suggestion was to now try moving the LSPV upward in its bracket to disengage the spring rod from the valve piston to take the LSPV out of the equation. Then said next step will be to verify the booster rod position using the SST noted above, which I will have to order. I'm going to try the LSPV thing tonight, and if no success there, dropping it off at the dealership tomorrow for them to check out.