Unending Soft Brake/Long Pedal Travel Issue
 

Hey guys I have been doing hours of research on the forums on this issue and have found a lot of good information, I am really looking for guidance on what priorities I should tackle first on this issue because I really am not that inclined to just throw money at it and hope it goes away.

I have a 96' SR5 with ~186k on the clock and I have already replaced/done the following...

Rear cylinders
Rear drums and shoes
Front rotors and pads (several times due to warping)
Passenger side caliper (Was frozen and the pistons were in terrible condition when I bought the vehicle)
Fluid flush/bleed (Done myself with 2 man method and at a local dealer and again at a trusted shop)
Bell cranks and adjustment (were both rusted frozen when I originally purchased)

Despite all of this I still have an extremely soft pedal with very long travel. There is almost a dead zone for the first half of the pedal which I thought would be remedied with an adjustment, but to no avail. There is a little feedback in the pedal towards the later part of the pedal travel and the brakes eventually somewhat catch, but even then I never feel like I am getting the stopping power that the car was designed to deliver. I originally chalked it up to just being the brakes are underpowered as many people decide to make the TBU, but last year my brother purchased a '02 Limited and the difference is night and day and his operates as I imagine it should with a consistent feeling in the pedal throughout the travel that doesn't require you to stomp on your brakes anytime you're traveling more than 35 mph.

Anyways, I am just looking for some advice on what you guys think I should tackle first and hopefully I'll be able to sort this out before I make another long trip back to school.

Cheers

If there are no leaks, the pads are not worn out & the calipers are both good, the rear shoes are not worn out & are properly adjusted and the whole system is properly bled then you most likely need a master cylinder. Toyota master cylinders sometimes just die and you end up with way excessive pedal travel and poorly functioning brakes. As for you brother's 02 it has a completely different master cylinder/ABS/power booster set up than your 96. You don't really need the TBU unless you run oversized tires or tow something heavy.

Sounds like the master has failed. Did you check which calipers you have on the front? When i converted my 99 to the tundra brakes, the pedal travel increased but the stopping power was better, just delayed a bit.

I would agree with Mr. Coffee

I have a 2000 and I messed around with the brakes alot when I first purchased it. I finally ended up flushing and replacing the piston seal kit in the main. Those rubber seals will start to degrade and if it's still original your master seals had a hell of good run.

scroll way down last pic
https://www.toyota-4runner.org/2885174-post29.html

it's a different story but I undid my tundra brake upgrade because I don't like how much extra travel the pedal had running the front tundra calipers. I swapped back to stock sized calipers in the front and I will never go back to the tundra calipers. way better with stock size calipers. just a personal choice for me because I like a nice firm pedal to engage when I press the pedal.

Is it soft or spongy?
if when you first apply the pedal and it sinks to the floor, and then you get some brake action after you pump it a bit, it's likely an internal leak in the Master Cylinder.

I have a spare (used) OEM master cylinder that was working just fine before it was removed.

I’ll send it to you if you just pay shipping.

Thank you for being the first to point this out and I really do not tow often just the occasional jet ski and U-Haul Trailer.

I have the stock calipers, but they are the factory upgraded ones which I believe were designed to fit the larger wheels that also came as an option on my Runner. Please correct me if I am wrong. My vehicle's sticker indicates it came with 265/75/R16s.

Interesting you say that I don't think I've ever heard of someone saying anything negative about the TBU, but I will definitely take that into consideration if I ever decide to go ahead with it.

The best way I can describe the feeling my brakes give is that the first half to two-thirds of the pedal travel provides no stopping power whatsoever and then after that the actual portion of travel that causes the car to reduce speed is extremely soft and the pedal must essentially go to the floor in order to come to a complete stop. Thank you for that insight it seems that the MC is likely the culprit.

Thank you for offering! I will PM you to see if we can work that out.


Again thank you everyone for getting back to me on this so quickly. Unfortunately work has swamped me these past couple of weeks, but I greatly appreciate all of your recommendations. I am going to do another once-over of the whole braking system and double check I'm not missing something obvious here, but I imagine I will ultimately end up replacing the MC and hopefully that will put an end to all of this.

Not to argue with anyone here, but my experience is that a failing master cylinder will usually stop fine, but the pedal will sink to the floor while sitting at a stop light. If your pedal stays put once fully engaged, I wouldn't jump on replacing the MC.
My 96 had excessive pedal travel. The only thing that helped was replacing the rear drums with junkyard Toyota parts and the pads with Toyota pads. I found the parts store pads I bought did not have the same geometry as the Toyota ones. Then bleed and bleed again. I've also read on here that a curating the abs on a dirt road then bleeding can improve pedal travel, but I haven't tried that one yet.
Also, make sure the rear pads are self adjusting properly, and that you bleed following the proper sequence of wheel order.

OP I'm having these same issues with my 96 I just bought. My pedal goes all the way to the floor before the brakes engage. And even then there is no resistance to the pedal. And I dont believe it's the master cylinder because when the trucks off and I pump the brakes they get tighter with every press. Let me know if you fix yours.

Really need to make sure the rear brakes are adjusted properly. They should just start to rub the drum a little when adjusted right. Obviously should not drag but there needs to be contact. I've had 2 experiences with mud in my drums causing the shoes to self adjust inwards and it scared the hell out of me once I got on the road. They would also seemingly pump up but the only cure was to remove the drums and clean things up and adjust the brakes.

I literally bought my 4runner last night and it's my first. So I'm just learning as much as I can.

You've come to the right place. Many helpful people here and great information. Give a read to all the stickies. Oh and congrats on your purchase.

So I tested my parking brake and no bueno. Any good reading material on here for adjusting the rear brakes and parking brake?

No bueno? I assume you mean you pull it back and it doesn't lock in. That's a sign your rear brakes need to be adjusted. Just do it as I described in my previous post. When you remove the drum, there's a star wheel that you adjust outwards, expanding the shoes. Do a little at a time until the shoes rub the drum. After you do that your parking brake should hit in 7-9 clicks. If you need in depth description and pictures just search "rear brake adjustment"

After you adjust your star wheels there is a specific procedure for adjusting the bell cranks. AKA that bolt on each one.

If you have a ridge on your brake drums it will make it difficult to adjust removing the drums. You can adjust the starwheel from the back of the brake plate through the slot with the rubber plug in it.


Sent from my iPhone using Tapatalk