My forever brake issue

I've had shit brakes since I got the truck new. They feel like there's air permanently in the lines. I've bled literal gallons of ATE Typ 200, both old-school style and on the stealership machine, with virtually no change. Thinking maybe they're under-sized for my weight (6,200# empty), I upgraded to T4R fronts a couple years back. Only change that gave me was a new quirk: I get fucking fantastic, race-car-sensitive brakes if I step on the brakes during the last 30% of a freeway cloverleaf (lateral shift of weight), but only while turning. Other than during lateral weight shifts, the only time I get brakes approaching normal is when I pump them up, which is now my normal mode of braking (so much so that I find myself doing it in my F250 and my wife's Rav4, neither of which need it).

An old thread that's still valid: https://www.tacomaworld.com/threads/brakes-dont-seem-to-want-to-bleed.429073/#post-20467898

Anyone figure this one out? Anyone want to diagnose this before I take the family into the Maze at the end of March?

Dunno if it will help, but I've got another thread in the Suspension forum about alignment that won't stay set. And rather than typing up my extensive list of mods, you can get a sense of them over there: https://www.tacomaworld.com/threads/alignment-settings-wander.651299/#post-22647917

 

Have you ever replaced the calipers? Like put new ones on? Look at the bleeder valve, they have to be on the top of the calipers and not the bottom. I've seen people run into problems like this where they install the right caliper onto the left side and the left on the right side so the bleeders end up on the bottom.

You'll never be able to bleed the air out period; it'll feel squishy until the calipers are swapped from left to right so that the bleeders are at the TOP of the caliper and not the bottom. Just a thought, if yours are correct then your problem may be the master cylinder is going bad, there is a seal in there that overtime will fail.

 

Calipers are a year old, if that. Installed correctly.
Same issue since day one. Unless it's been a bad MC out of the factory, I'm doubting it's that. I may just throw parts at it, and hope for the best.

 

I'm honestly considering just yanking the ABS out completely.

 

Sounds like a lot of frustrations; At this point if I was you, I would've set fire to the truck already. (not saying you should lol)

Well, I am not sure what to tell you; looks like you've done basically everything anyone would do

 

Have you ever driven a different Tacoma?

 

Not long-term. But I've driven enough different vehicles, including Toyotas, for enough decades that I know my Taco brakes are shit.

 

Man....Sorry to hear about your issues and headaches! Hoping the folks here on TW can help...

Wondering if the brake lines are leaking.....and or have your checked the master cylinder yet?

Keep us posted - good luck.

 

I only asked because every Tacoma I've driven that has stock brakes their brakes completely sucked and didn't compare to any other vehicle's brakes that I've driven. My stock 1950 Chevy pickup stopped better than a Tacoma.

But your reply reads like you have driven other Tacomas for at least short term so that throws my thought out the window.

 

Try a new Factory Toyota M/C is what I would do next.

 

I've never really considered a MC, but maybe I'll look into it.

Just a couple hours ago I crushed my DR brake line while pulling the leaf pack to swap bushings. So now I need to do brake work anyway. May as well add a MC to the project.

 

Are u using cheap parts or oem? That makes a difference also...

 

My experience with brakes that require pumping has has always been master cylinder.

Here is my first hit on Google when searching for "failing master cylinder",

 

Adjust the rear ratcheting stars in the drum brakes. Ensure you can't turn it more than 180* by hand. This will pull the brake pedal up and allow for a firmer and more consistent brake engagement.

Also check the bolts in the MC to brake booster. Also ensure vacuum seals in the line going to the brake booster. Albeit the brake booster relies on vacuum pressure eot operate so any compromised rubber lines may contribute to your issue.

 

Read through PO's last post before reading this, an internal leaking MC was all I could think about. Air in brakes, pumping won't do a lot, however with an internal leak in a MC it for sure will. If I were to rule out air from the ABS, since OP has said the dealer as done it (I would assume used a tool to open up the ports), an internal MC leak seems to be the most likey thing going on.

There's an easy enough test though. Start the truck, and leave it in park (or the e-brake on...) and force fuck your foot on the brake pedal and keep it there. If it sinks... bad MC.

 

Never assume everything is perfect from the factory. I've seen/repaired more than enough factory shit in my life to say it absolutely does happen. Some seal/o-ring could have been missed, pinched during fab/install, etc... It happens.

 

You may not have a problem, other than the way Toyota designed this breaking system. My 2008 has a sucky brake pedal feel since I drove it off the lot. The brakes function OK, but the brake pedal feels like I’m stepping on a balloon. I took it back to the dealer about a week into my ownership experience, and their lead mechanic demonstrated they work fine, even with their crappy feel. I’ve gone through at least one set of pads and drums, including flushing the system every 2-3 years, and the pedal feel never changed.

Every other vehicle I’ve ever owned had a firm feel, including my 1994 Hilux. That’s what I’m used to feeling, and I feel I can regulate threshold braking far better with a firm pedal.

Not sure another OEM master will provide a better feel, so maybe a different Toyota master? I decided long ago that I wasn’t going to throw parts at the system hoping to find a better solution, so I just live with it. The brakes work, and I have a functional antilock system. I know that’s what I’ll rely on instead of threshold braking.

 

Just to throw in my $.02, my 2008 feels the same. I've had both calipers changed by me, will have to double check my bleeder valve position now.
Had the mechanic at stealership tell me awhile back my brakes feel squishy. I've had but fixed a leaky line.
A few months back I've had a new frame= some new brake lines, everything taken off and put back together again, and still squishy brakes.
(Guess I should've taken the opportunity to blame them, get them to fix it, but was too happy with just getting the frame done).
I too pump my brakes, maybe this summer I'll give the whole thing another look.
Not much help, but you're not alone, OP. Good luck, keep us posted.

 

I'm not a cheap parts guy. Certain things Toyota brand only, certain things aftermarket, certain things upgraded/performance aftermarket.

While the problem has been around since I got the truck new, I'll check out the MC and report back. With 125k miles on the original, it wouldn't hurt to change it anyway.

 

The calipers are high maintenance because they are 4-piston each. Mechanics and Pro-DIY'rs can't just push the pistons back in (maybe they can if the brakes are pro-actively changed at 50k miles with 1/2 pad life remaining), but that's typically what ends up happening during a routine brake replacement after the piston has been fully extended out the caliper without lube. The seals and boots really need to get replaced during a brake job to prevent the pistons from 'slowing' or partially seizing. This also gets all the crud and debris out of the caliper, especially the outer channel since a regular fluid flush never gets it out. OEM Seal, boot, and clip kit is only $20.