FJC Master Cylinder Swap?

[pearlj10]

I really, really dislike the feel of the fourth gen brake pedal (like many others on this forum). Specifically, how far you have to push the pedal to activate brakes and how soft the pedal feels. I have an 03, all new calipers, stop tech rotors and pads, SS lines, and two recent bleeds by dealer. I've had the truck looked at multiple times by two dealers and they all say "it's normal."

I have an 2011 FJ work truck and the brake pedal feels fine, like you'd expect in a truck, and what I'd like in a 4R. My question: if I install a used FJC master cylinder (and the attached abs, etc ecu) do you think it's possible to match up the 03 4R wiring harness to the FJs plugs/wiring? Foresee any issues if the wiring works?

Thanks!

 

[robaroni]

Have you driven other 4th Gen 4Runners and found the brakes to feel the same? I've never had a complaint. :driving:

 

[BlackWorksInc]

It probably won't work as the wiring is slightly different (not just the connectors, but physical wires if I remember right.)

Have you looked on the forum for alternatives? Some members reported better brake feel with stainless steel lines.

 

[pearlj10]

Robaroni: I have driven several 4th gens and there is a slight discrepancy between the 2003 and 2004, in my opinion, and the newer ones. However, I test drove a 2014 and still thought the pedal felt soft and traveled too far. Then again, the sample of 4th gens I've actually driven is small. Maybe I have been in the ones with a lot of travel play and others are better. I just don't get the apparent difference between the 4R and contemporary FJCs, or older models like land cruisers.

Have you driven other 4th Gen 4Runners and found the brakes to feel the same? I've never had a complaint. :driving:

 

[pearlj10]

Blackworks: I was thinking I'd have to splice the 4r harness into the FJC plugs to make it work but was hoping the FJ had similar wiring, albeit different wire colors and plugs. I have front and rear SS lines to the calipers, and extended SS Lines from the body to rear axle. All new. No rubber hoses left. I honestly couldn't tell a difference between rubber lines and SS but then again I live in AZ and the hoses looked to be in good shape.

It probably won't work as the wiring is slightly different (not just the connectors, but physical wires if I remember right.)

Have you looked on the forum for alternatives? Some members reported better brake feel with stainless steel lines.

 

[M1911]

I really, really dislike the feel of the fourth gen brake pedal (like many others on this forum). Specifically, how far you have to push the pedal to activate brakes and how soft the pedal feels. I have an 03, all new calipers, stop tech rotors and pads, SS lines, and two recent bleeds by dealer. I've had the truck looked at multiple times by two dealers and they all say "it's normal."

Before my frame replacement, I had the exact same issue. The brake pedal was soft and required a lot of force. My brake work had been done by a local shop for years.

After my frame replacement (which included new brake lines), my brake pedal is much firmer and requires a lot less force.

All I can guess is that neither of the two dealers you took it to bled the brakes properly.

 

[BlackWorksInc]

Before my frame replacement, I had the exact same issue. The brake pedal was soft and required a lot of force. My brake work had been done by a local shop for years.

After my frame replacement (which included new brake lines), my brake pedal is much firmer and requires a lot less force.

All I can guess is that neither of the two dealers you took it to bled the brakes properly.

New hardlines as well?

 

[M1911]

New hardlines as well?

I don't know. I assume so but I haven't been under the truck to look. I can't imagine that they spent the time trying to pry the old hard lines off the rusted frame. It is freezing out and snowing like a banshee so I probably won't be under the truck for a while.

I wouldn't expect that changing the hardlines would make a difference, though. I can imagine that the old soft lines might have weakened, so that as you press the brake pedal some of the force from the increased pressure goes to swelling of the lines rather than movement of the pistons, thus leading to the soft pedal and increased required effort. So my assumption is that the improvement I have experienced in brake feel has been due to the replaced softlines and proper bleeding.

But that is just my assumption.

 

[zonianbrat]

It sure would be nice if there was a way to get away from that abs-solenoid-BS system all together and still be able to maintain at least ABS. My friends 07 Tacoma had a normal master cylinder. I assume Toyota realized after the fact how stupid of a design the system I have is.

 

[BlackWorksInc]

It sure would be nice if there was a way to get away from that abs-solenoid-BS system all together and still be able to maintain at least ABS. My friends 07 Tacoma had a normal master cylinder. I assume Toyota realized after the fact how stupid of a design the system I have is.

Its not exactly a bad system and it is more efficient and stronger than a traditional vacuum system. This is why it is used on ALL J150 Platform vehicles (FJ Cruisers, 4Runners, GX470, GX460, and 2010+ Tacomas) as well as the Tundra, Sequoia, Land Cruisers (LC100+)

If anything Toyota as well as other manufacturers are going to eventually use nothing but these systems. Newer engines actually have far more unstable vacuum in terms of doing actual work like a brake booster than older vehicles. This is part of the reason we no longer have "rats nests" and everything is electronic, its due in part to the fact that these engines are being manipulated so heavily on a mechanical level (electronic throttle VVTi, GDI, ect.) that some cars even have vacuum pumps to provide constant vacuum.

The issue is more rooted in the general principle of "more complication= more failure points." The other obvious complaint is that these systems don't feel as "stiff" as our older vacuum assisted vehicles because they are far better at providing assistance which makes the brakes feel very unnatural. Honestly I wouldn't be surprised if all it took to adjust the brake feel was a software update to modify how the feedback back feels like in the 3rd Gen Prius when they first came out (you don't actually control the brakes for the first 1/4~1/3 brake pedal travel, the system mimics back pressure to make you think you're doing something; when they first came out that feedback was too soft and customers complained, the fix was a reflash to stiffen the feedback.)

The problem is that Toyota thinks this is what most soccer mom drivers want (which is probably not untrue) and while the pedal feels soft, brake effort doesn't really change (unless you're starting to have issues with the system such as stuck calipers, failing accumulator, ect.) it just feels soft. Also Toyota modules are notoriously difficult to crack and I don't see much of an aftermarket for cracked/stand alone ABS/Skid Control ECUs.

The valving between the FJ Cruiser & 4Runner units in 2005+ Master Cylinders is identical, the only difference is the physical ECM bolted to the side of the unit. I figured this out when dealing with this particular 4Runner:
http://www.toyota-4runner.org/4th-gen-t4rs/174680-class-participation-time.html

 

[zonianbrat]

I see where you are coming from Blackworks. Still to engineer and produce a part that is not at all servicable and affects braking is in my opinion a safety hazard and just plain dumb. Does a vehicle that weighs what the 4 runner does really need a hydro-boost system for braking? I understand maybe for functionality of a 4x4 system such as A-trac. Let's not get started on how ridiculous the price is when this system fails.I understand that most newer vehicles may be using this technology now and that is what it is. My point is that I wish some of these companies would just produce a good ole truck like the older 4 runners and Tacoma's that would just run and not throw a code for every little stupid thing like a gas cap being loose. They are getting way too automated and phasing out the shade tree mechanic and do-it-your-selfer! I mean c'mon there are cars out there that "sense" moisture on the windshield and turn on the wipers for you. Hello Captain Lazy-ass. I'm sorry and I do know that most of the newer vehicles out there have some amazing and safer features but I guess I'm old school.

 

[BlackWorksInc]

I see where you are coming from Blackworks. Still to engineer and produce a part that is not at all servicable and affects braking is in my opinion a safety hazard and just plain dumb. Does a vehicle that weighs what the 4 runner does really need a hydro-boost system for braking? I understand maybe for functionality of a 4x4 system such as A-trac. Let's not get started on how ridiculous the price is when this system fails.I understand that most newer vehicles may be using this technology now and that is what it is. My point is that I wish some of these companies would just produce a good ole truck like the older 4 runners and Tacoma's that would just run and not throw a code for every little stupid thing like a gas cap being loose. They are getting way too automated and phasing out the shade tree mechanic and do-it-your-selfer! I mean c'mon there are cars out there that "sense" moisture on the windshield and turn on the wipers for you. Hello Captain Lazy-ass. I'm sorry and I do know that most of the newer vehicles out there have some amazing and safer features but I guess I'm old school.

Well the issue is that its driven by regulations and emissions a lot of times. Like I said, many vehicles these days produce unreliable vacuum (due to engine design evolution spurred on by emissions and power goals) so instead of running vacuum pumps, they combine a far more powerful hydraulic pump into the ABS system. Now they have much better control over ABS & VSC functionality (not just in 4WD, that's a neat side effect.)

The unit IS technically serviceable, there's 11 pages in the FSM about how to tear it down and rebuild it. Getting the parts on the other hand is trickier and no dealership rebuilds them (just like no dealer really does transmission, engine, or differential rebuilds unless specified by a TSB, Campaign, or Recall.) That part of the problem is something Toyota may have control over, but as far as I have seen; it's more cost effective to replace assemblies than to tear an assembly down for 1 sub-component. Its just a reflection of how complicated these systems are, this isn't a carburetor or a simple single fuel injector system. We're lucky we can even do anything with the vehicles these days considering how computerized they are. Give it another decade or two when EVs are the norm, doubt many people will be re-winding their motors or rebuilding their inverter assemblies in their garages. The point is that they don't want you to be tinkering with their engineering, that's part of why Toyota's are so notorious to crack their ECMs and modules. Not to mention that most everything needs a scantool and a strong understanding of complex ideas such as computer networking and a healthy understanding of electrical work to diagnose/fix. As far as manufacturers are concerned, they'd rather not have weekend-wannabes breaking their cars and then trying to sue them for their own ineptitude. For better or worse, that's what its like these days; weekend tinkerers are either going to have to be borderline mechanics in both skill and equipment, or take it to a dealer/shop.

That's not to say I don't think some of this crap is ridiculous, blind spot monitoring on a Corolla or Camry, hell even the 4Runner? I have never had an issue with blind spots with properly adjusted mirrors on anything less than a box truck or large trailered vehicle. Excessively aggressive VSC/TRAC systems that are supposed to help? Honestly every damn manufacturer I have driven is far too aggressive with their application (mainly due to idiots who got themselves killed from inexperience and thus now we all are punished for it.) I have had some vehicles almost throw me into oncoming traffic when VSC/TRAC kicks in because it kicks in at the wrong times or undermines my attempts to control a vehicle in a mild emergency. I'm not even going to start with what's wrong with Brake Smart Technology...

 

[zonianbrat]

I agree Blackworks. I guess it will just take some getting used to. So I have a question for you. It is unrelated to this topic but it isnt like this is a busy thread anyway. My t4r is having trouble firing on cold start. No codes being thrown and battery is only a year old. It turns over really good just has trouble firing. It doesnt just turn over it really tries to fire but just cant quite do it (if that makes sense). Once it is started once it starts up great the rest of the day. Spark plugs probably have 20K on them. They are ac delco's though. Have any other ideas that I can check? Thanks in advance.

 

[BlackWorksInc]

I agree Blackworks. I guess it will just take some getting used to. So I have a question for you. It is unrelated to this topic but it isnt like this is a busy thread anyway. My t4r is having trouble firing on cold start. No codes being thrown and battery is only a year old. It turns over really good just has trouble firing. It doesnt just turn over it really tries to fire but just cant quite do it (if that makes sense). Once it is started once it starts up great the rest of the day. Spark plugs probably have 20K on them. They are ac delco's though. Have any other ideas that I can check? Thanks in advance.

It's not taking excessively long to crank, but it is taking just a little bit longer than you remember to crank right?

 

[zonianbrat]

Not quite. It is a definite problem. The other morning I had it in the garage. It had set for 2 days and it would not fire up on it's own (it was just turning over). I let it do this for whatever the time limit it is that it tries to start on it's own without me holding the key in the start position. I did this twice and it did not fire. Third time it finally started to fire but she didn't like it. Since then every cold start (after at least sitting for 12 hours) was hard to fire but not as bad as the other morning. Then today it wasn't going to crank. I floored it, not sure if it helped but it did fire up. Like I said before though every start after the cold one is fine. It is a cold start problem.

 

[BlackWorksInc]

Maybe try cleaning the throttle body and then disconnecting the battery for about 5-10min then allow the vehicle to idle with no loads for about 5mins to relearn its idle? That may help?

 

[zonianbrat]

Ok! I will give this a try tomorrow and get back to you with details. Thanks Blackworks.

 

[182jose]

It probably won't work as the wiring is slightly different (not just the connectors, but physical wires if I remember right.)

Have you looked on the forum for alternatives? Some members reported better brake feel with stainless steel lines.

Hey blackworks i have an issue.. and as i see it you are the only one who knows cuz in venezuela at any dealer they didn't know this car or anything related to the 2008 4R V8 even the scan tool doesn't read that truck they read it as a sequoia or tundra they say cuz has the same 2UZ engine...


I live in Venezuela i have braking problems in my 2008 4runner sport V8 as this truck is imported in my country we don't actually have many spare parts for the 2008 V8.

Toyota Venezuela only assembled the V6 one till 2007 or 2008 not actually sure but what i am sure is that i can't find the master cylinder 47025-35071

i only could find the 47025-35112 with apply for 2008 fj cruiser

i want to know if i can mount this FJC master cylinder on my 2008 4runner sport V8

 

[isdriven]

I really, really dislike the feel of the fourth gen brake pedal (like many others on this forum). Specifically, how far you have to push the pedal to activate brakes and how soft the pedal feels. I have an 03, all new calipers, stop tech rotors and pads, SS lines, and two recent bleeds by dealer. I've had the truck looked at multiple times by two dealers and they all say "it's normal."

I have an 2011 FJ work truck and the brake pedal feels fine, like you'd expect in a truck, and what I'd like in a 4R. My question: if I install a used FJC master cylinder (and the attached abs, etc ecu) do you think it's possible to match up the 03 4R wiring harness to the FJs plugs/wiring? Foresee any issues if the wiring works?

Thanks!

I agree with you on the peddle feel, bothers me too. I was hoping SS lines would solve the problem, but form what you are reporting, it's not looking that way. I've never had a problem stopping, just have to dig in a lot.

What type of brake pads are you running?

 

[rooost]

Cars are amazing and the technology to get there is very complex......Agree that it is totally not necessary, except for evolution and the race to make all things mechanical silicon, and it always takes a few generations for things to actually function properly, if you own a GM it takes about 20 years. they finally figured out the 2-4-6 from the 80s! but if you want old technology...it is available, in an older car
.
.
.
Personally I understand why old guys tinker with old cars, I am settling into my spot of about 1995-2009....never owned a carburetor! and hopefully will never have to own much more complicated than my 07 V8 Limited and my 2005 Acura RSX.
.
.