Rear brake upgrade

[ShannanC]

I had a 57 Chevy Bell Aire with a 330hp 350 and factory 3:17 positrac rearend when I was younger. It did 0-60 in 5.45 seconds. That car had the aerodynamics of a garage door and weighed a hell of a lot. A super charged V8 with 2 extra injectors in a 3rd Gen 4runner doing it in 5 seconds or less doesn't sound out of the realm of reason actually.

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[Brilliant]

I had a 57 Chevy Bell Aire with a 330hp 350 and factory 3:17 positrac rearend when I was younger. It did 0-60 in 5.45 seconds. That car had the aerodynamics of a garage door and weighed a hell of a lot. A super charged V8 with 2 extra injectors in a 3rd Gen 4runner doing it in 5 seconds or less doesn't sound out of the realm of reason actually.

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4.5 and 5.5 are vastly different.

 

[ShannanC]

Not if you consider hp to weight ratio with the gear ratio figured in also. I'm pretty sure that the supercharged Toyota V8 with the 9th and 10th injector mod pumps out more than 330hp. His 4Runner does not weigh as much as my 57 Chevy did and his gear ratio is far greater than mine. Having said all of that IMO his acceleration HAS to be faster than my 5.45 0-60. And remember a 4.99 second 0-60 is still a 4 second 0-60. So....it's still easily in the realm of reason.

 

[sportsterchop200]

Any new info?

It's been a year anything definitive about the wheel cylinders being an improvement?

 

[ThePurposeIs]

All right I haven't been on forums much but I've been reading for at least 8 hours the past few days and I still cannot figure this out.

I took my 2wd sr5 '99 to the shop for them to do lower control arm bushings and brought them a pieced together 13WL 04 Tundra caliper with new rotors and pads while they were in there. I had no idea what I was getting into... We think the master cylinder isn't keeping up because after extensive bleeding the truck's brakes are grabby toward the end and squishy most of the time. The rear cylinders were bad so they replaced them with autozone........YUCK. I am a bit of a perfectionist and I like to understand my cars and trucks and do things right. Since the front brakes have been upgraded and I'm planning to upgrade the master cylinder, (1st thing I need help with) a better wheel cylinder in the rear seems like a fantastic idea. Even if all it means is "buy the oem part!" I plan to upgrade to calipers in the rear someday but for now I think I can get the truck set up very nicely. Years of building miatas, rx8's, rx7's in every way from oem+ to rally and rock crawling to time attack and drifting, I want to delete ABS because I know how to use a brake pedal. My plan is remove abs box and intelligently re-use stock lines and install a manual proportioning valve (2nd thing I need help with: How do I find out what size valve I need? I have read where people installed the wrong sized valve and it did not operate correctly. Do I need to read a book or take a college course to understand this stuff?) Research into this topic has led me to this thread and also here:

Upgrading wheel cylinders?

That thread died a year before this one and so I'm trying to briefly resurrect this thread or, if y'all advise, I will just start another thread to end all the confusion regarding this brake upgrade nonsense. Some people recommend things as crazy as T100 booster with a GM master cylinder. I think my plan is go to junkyard (tomorrow) and get a 1997 T100 booster and master cylinder and I HOPE TO GOD it is the right size I am looking for. (3rd thing I need help with) Which master cylinders are the best for upgrading 1999 brakes and which boosters are best to swap in to accommodate other perhaps more desirable master cylinders. The older toyota trucks have so much more information about these types of upgrades. FZJ80 master cylinder, proportion valve, delete rear proportion valve, caliper rears, boom done. I recently touched and gave love to every part of the truck but this brake complication has held me up for over a week now and I'm currently driving around with a reeeeally sketchy brake pedal.

Happy to be a part of this forum and I'd like to contribute in the future.

 

[sleepydad]

All right I haven't been on forums much but I've been reading for at least 8 hours the past few days and I still cannot figure this out.

Happy to be a part of this forum and I'd like to contribute in the future.

lots of info in your post. thanks for that, makes it easier.

I would have described my TBU adventure similar to yours. peddle softer than I like it and brakes were grabby at slower speeds. nothing I would describe as sketchy but... just not what I liked.

2 things I have found.

the masters on these trucks are fine, just make sure the seals are good. the seals start to crack/break/fall apart after 20 years. not a hard thing to do just messy.

see the last pic on this post

https://www.toyota-4runner.org/2885174-post29.html

other thing I have found

using a vac bleeder pulling + pressure bleeder pushing was needed to get all the air out of this trucks system. to be fair this was a re-do on the entire brake system but... I also did this to my other trucks and it made a huge difference.

getting all new brake fluid into the system made a big difference. it took 3 bottles of prestone brake 12 oz to 100% exchange all the old fluid with new fluid.

https://www.toyota-4runner.org/3376163-post145.html

These trucks have a great braking system it just needs to be maintained. if you make sure the master seals are good, you don't have any terrible leaks, all fresh fluid it will work great. IMO.

 

[ThePurposeIs]

Thanks for quick response!!

So the mechanic is pretty brilliant but I don't trust him 100%. He said he worked on the truck for a long time trying to get the brakes to work, even bleeding each line on the ABS. I thought I would just let him install the brakes so he had access to more tools than me. He used a power bleeder HOWEVER one of his mechanics installed the brakes upside down I.E. the bleeder is now at the bottom of the caliper instead of the top. When I got an alignment (after having them install the whiteline LCA bushings) the mechanic (old crusty looking guy, always a good sign IMO) said "of course your brakes aren't bleeding correctly, they're installed up-side down!" My truck was definitely not properly maintained before I got it. When I first bled the brakes, the fluid was the darkest, dirtiest color I had ever seen so I've already swapped in a used MC and booster.

I went to a local 4Runner specialist called The 4runner House which is in Garland (wow this guy is awesome. I think his type of business is truly amazing. If anyone needs random hard to find 4Runners parts he probably has it) and he assured me the orientation of brake calipers doesn't matter and that I should upgrade the master cylinder to compensate for the increase in size of caliper. However he also sold me a used master cylinder and booster for 99 so maybe it's old and tired and not giving full compression. He tells me the only way it would be bad is if it is leaking so I'll find out tomorrow when I flip the calipers and pull the MC to see how it's doing.

I've ordered a T100 MC rebuild kit 04493-60240 so I can rebuild the MC for the MC+Booster I'll get from the junkyard tomorrow

I'm okay with upgrading to the T100 setup (if it truly is an upgrade) so I'll be covered if I'm going to upgrade rear brake capacity in the future. I work for a dairy farmer in East Texas (Jersey Girls Milk Co. | 5326 E FM 852 Winnsboro, TX, US,75494 | 903-365-2449) and I would like to become more involved with delivering local meat and dairy from farms so I'll be towing some heavy stuff in this next year. Trans cooler is coming but haven't planned that out yet.

Other things to mention: I put a new power steering (autozone ugh), plugs/wires, valve covers with half moons and everything, dropped trans pan to clean, trans flush, diff seal, pinion seal, axle seals, steering rack mounts, basically changing and flushing all fluids so I'm trying to catch up on maintenance and make sure everything is ready to be driven long distances. Perhaps I should rebuild the 04 Tundra Calipers to make sure everything in the brake system is perfect? Stainless front brake lines come in the mail in 4 days and speed bleeder for front and rear (639560 639570) come in the mail tomorrow. I'm thinking I can resolve the soft pedal (it is too soft. barely stops the truck) with flipping the calipers and speed bleeders and worry about deleting ABS/T100 MC/booster/proportion valve/upgrade rear brake cylinder. I still don't know (A) if the T100 will be an upgrade or (B) which proportion valve or (C) which brake cylinder to get or if the autozone cylinder is fine and I should wait to swap axles to get locker or stronger rear end and calipers.

Again, thanks for your input.

 

[plcfcng]

Great that your catching up on all the maintenance that have been neglected on your 4runner. I have my opinion on the autozone wheel cylinders while they are not of the highest quality as long as they don't leak just leave them if you notice your master cylinder loosing fluid then do take a look back there. As far as the per-portioning valve I would drive it do some different type of braking like normal and panic. If it feels odd then consider changing it if it feels ok then let it be. how to determine which valve I would consider going to a custom shop that deals with brakes and get there advice. :biggrin2:

 

[martin Roberts]

rear brake cylinder diameter 01 T4R

I am rebuilding my rear brakes on a 1997 and trying to find the correct REAR brake wheel cylinder to order.

searched for hours and my head is spinning:clock:

I am trying to go with oem / Aisin brand

What is the correct part # and bore diameter ?

part # 4755035210 - 1" bore diameter is recommended by Camelback and rockauto, but seems the same Part number for Tundra

Part # 4755035190 - fits most Tacoma's but might have 7/8 bore diameter

Part # 4755026110 is recommended by ebay sellers

I have heard that the oem 4runner wheel cylinder bore diameter is 13/16 and 1 inch. ???

are the Master cylinders the same size for all 3rd gen 4runners?


Any help is super appreciated

My 01 T4R 4WD 16", no towing package, has 7/8 embossed on the casting,

 

[ThePurposeIs]

My 01 T4R 4WD 16", no towing package, has 7/8 embossed on the casting,

I think I've ordered from rockauto before and not received what I was looking for.

I'm running 47550-35210 tundra/4runner wheel cylinders with 231 tundra brakes up front, abs delete, 76 blazer master cylinder, then routed the rear brake line into the cab with a proportioning valve to adjust F/R bias. I can lock up my new 33 tires whenever I want and the brake feel is sensitive enough that I can control it in different situations. Everyone once in a while I do brake tests on different surfaces so I can dial in the proportioning valve. There are different theories about what bias you want for offroad/street driving etc etc.

I plan to shoehorn a 2002 sequoia rear axle on my 99 4runner (I want to abuse my 4runner harder than most so figure a stronger axle with caliper brakes would be helpful) so I'll make a thread about it when I start.