Toyota Rear disc brakes issue

[Hotwheels]

So I just put 4340 axles and rear disc brakes on my 94 4runner. I had to put a new booster on it and rebuild the front calipers. The problem I am having is the brake pedal feels like **** after I have blead the brakes. I dont have any leaks in the system. The rear brakes are sky-manufacturing rear disc set up with Chevy calipers and stainless lines running on the rear axle. I have a porportioning valve and 10lb residual valve comming off the master for the rear brakes. The only thing I can think of is I have a air pocket some where in the system and it has just not bleed out yet. Any thought or comments would be great.

Rob

[humpy]

to my knowledge a stock brake master cyl is big enough for the rear disk setup..i.e. it makes for a spongey pedal...we usually put a master cyl off a 93 yota t100 non abs on em and it works great...hope it helps...maybe someone else can help more??

[fabricator]

sounds like air
that have a 1" bore master on it?
always bleed farthest corner to the nearest to the master.
bleed porportioning valve last. if it had one
sounds like u dont have anymore
fyi...these trucks r the hardest units i have ever had to bleed

[Hotwheels]

yes has 1" master on it

[itbrokeagain]

Try a pressure bleeder if you can get access

[Hotwheels]

I have power bleed the brakes on my 4runner. The only thing I can think of at this time is I am using my stock ABS master cylinder and the rear part of the master is to weak and I need to change it to a non ABS master.

[Hotwheels]

So here is what I did today with the brakes. I have a 1" bore non ABS master cylinder on my 4runner. I have no proportioning valve and no 10lb residual valve on it at all. Took it all of to make sure it was not them. The runner had rear ABS and it is not hooked up at all. I have speed bleed the brakes and 2 person bleed the brakes and still have a ****ty pedal with the truck off and it goes to the floor when it is running. I am so fing pissed at this thng. I have also call sky and talk to someone there and he told me that everything I have done they would have done. So I am sunk any help would be great.

Rob

[pfreer3]

When you bled them, did you do the farthest away first (Left rear, right rear, right front, left front) to make sure you got the air out?

check your vaccum booster check valve (in the line) to the intake manifold. If you took it off and flipped it around, that might cause the sinking pedal when its running. it has a direction so that once manifold pulls a vaccum, the valve holds it. I've seen this problem on 2 different rigs that had poor brakes after the conversion.

Is this a new master cylinder? If not, the one you have may be bad.



Brakes are pretty simple...

[Hotwheels]

The vaccum valve is fine I never took it off, it is holding vaccum. The master is new and yes I bleed the brakes the right way from passangers rear, drivers rear passangers front, and drivers front.

[Hope Springs Hauler]

I have seen bad MC's even though they were new. Ask FlxRtd:o

[Hotwheels]

I tried the master that was on my runner that was good. it was a ABS master and from what I have read that is not the master I need so i got a new master from Davez offroad performance. I really dont think it is the master.

[fabricator]

Drivers Side Rear
Passenger Side Rear
Passenger Side Front
Drivers Side Front
the 1" master is plenty enuf for the brakes, this has been my experience anyway.

dumb question
is the calipers on the correct sides....bleeders at the top?
even if they are..i've had to unbolt caliper bracket and spin bleeder to tippity top then bleed....spin them back down and bolt them up after..

plenty of fluid coming out of each bleeder...no clog?
power bleeder?

only other thing i got is bench bleed the M/C

i feel for ya. i no exactly where you are comiing from on this. they freakin suck

i have cut my rusty frame out from the doors back and fabbed a new one in.. while all the time working around the calipers. refused to crack the lines .

[humpy]

Drivers Side Rear

dumb question
is the calipers on the correct sides....bleeders at the top?
even if they are..i've had to unbolt caliper bracket and spin bleeder to tippity top then bleed....spin them back down and bolt them up after..



im glad im not the only one that has made this mistake...lol..actually quite a few people have, its easy to do...

[Hotwheels]

calipers have bleeders are on top, I have power bleed the brakes, I bench bleed the new master.

[Hotwheels]

your fix might be simple. I've found that the 1" bore rule doesn't apply to all. For a long time I was in the same boat. Then I went to a GM 1-1/8 MC and all my problems disappeared. I've got a nice strong pedal with a great grab. I was shocked at what an 1/8th increase does for a spongy pedal.

That what I found out today. The 1" bore toyota master is not pushing enough fluid causeing the low and spongy pedal in my 4runner. I am going to buy the rockstomper GM master and bracket to fix the issue.

[Hotwheels]

I have been PMing ericb on pirate and have been reading his stuff for a few days now. I can fab it up right now I will have to let it sit because I have other things I need to work on at work.

[gothodgie]

i got some 1/4" plate if you need a piece...

:beers:

[Hotwheels]

Great help I will be making this ASAP.

[Hotwheels]

Are the factory studs on the booster not long enough to just use?

[fabricator]

i got one of these with a master bolted to it somewhere
your welcome to come and check it out
if it will help

[Hotwheels]

Stickman how soft was your pedal mine goes to the floor on the first pump. I was a little worried about just using the 1 1/8 GM master with that low of a pedal. I was thinking about using the 1 1/4 master instead. I have read ERICB page on the brake and was wonder what your pedal felt like before and after the master change.

[Hope Springs Hauler]

Going from the 1" to the 1-1/8" will be a ~23%increase in fluid volume. The 1-1/4" will be a 56% increase over the 1".

I'd be careful about going too big or the brakes will be very sensitive.

[eighty3bronco]

if you still have issues. take a pair of vice grips and block the fluid on the rubber lines. I had to do this on my cherokee to find out that I had bad front calipers. it will tell you real quick if there is still air in the main lines. when I did it i clamped both sides of the rubber lines to make sure that the rubber was not expanding.

[pfreer3]

I call BS on the 1" M/C not working... I have the same setup as you.

what calipers are you using?
I have the 1" V6 M/C with 1985 monty carlo calipers, (sky brackets) and have awesome brakes.

I even still have the Prop valve (lever tied up) in-line.

Davez off-road parts are usually pull-off parts, not new I believe. Least not what he sent me.

My guess is you still have air in the lines, or your M/C is bad...

[humpy]

I call BS on the 1" M/C not working... I have the same setup as you.

what calipers are you using?
I have the 1" V6 M/C with 1985 monty carlo calipers, (sky brackets) and have awesome brakes.

I even still have the Prop valve (lever tied up) in-line.

Davez off-road parts are usually pull-off parts, not new I believe. Least not what he sent me.

My guess is you still have air in the lines, or your M/C is bad...

agreed!!!!!!!!!!

[Hotwheels]

I call BS on the 1" M/C not working... I have the same setup as you.

what calipers are you using?
I have the 1" V6 M/C with 1985 monty carlo calipers, (sky brackets) and have awesome brakes.

I even still have the Prop valve (lever tied up) in-line.

Davez off-road parts are usually pull-off parts, not new I believe. Least not what he sent me.

My guess is you still have air in the lines, or your M/C is bad...

That is nice that you have the same set up as me. The master that I got from davez is new and not used. I have no air in the lines. I have bleed the **** out of the brakes and know I have no air in the line. The set up on your 4runner with the rear dics brakes and my 95 runner I have read that people with older trucks and 4runner dont have problem but people with new runners and truck have had this problem.

[gothodgie]

For all of you who do not know Hotwheels, he is a good friend of mine and knows his sh** about mini trucks and 4runners. He has also been a Toyota mechanic for about 6 or 7 years now. I talked to him last night and he has done everything you guys have mentioned several times and them some.

pfeer, humpy... I have seen many of these conversions done on the 1st generation runners and trucks as you have and they get done without any trouble. I also know a few guys that have done this on 2nd gen 4runner and had these problems. After talking to Rob(hotwheels) i think he has come to they conclusion it has to do with the 4runners that came with ABS.

So all that being said... I hope i have not made anybody mad or steeped on any toes. I am not directing this at onyone in particular. I just thought everybody needed to know that Rob is not a newbie or some one who does not know anything about toyotas...

I know everybody is just trying to help, but some just seem to be beating a dead horse...

Rant over... :D
:beers:
Chris

[Hotwheels]

For all of you who do not know Hotwheels, he is a good friend of mine and knows his sh** about mini trucks and 4runners. He has also been a Toyota mechanic for about 6 or 7 years now. I talked to him last night and he has done everything you guys have mentioned several times and them some.

pfeer, humpy... I have seen many of these conversions done on the 1st generation runners and trucks as you have and they get done without any trouble. I also know a few guys that have done this on 2nd gen 4runner and had these problems. After talking to Rob(hotwheels) i think he has come to they conclusion it has to do with the 4runners that came with ABS.

So all that being said... I hope i have not made anybody mad or steeped on any toes. I am not directing this at onyone in particular. I just thought everybody needed to know that Rob is not a newbie or some one who does not know anything about toyotas...

I know everybody is just trying to help, but some just seem to be beating a dead horse...

Rant over... :D
:beers:
Chris


Thanks, Chris

[gothodgie]

Thanks, Chris

Now get the d*** thing fixed so you can go wheeling .....:singingbev:

:beers:

[fabricator]

Believe it's because of the name Rob....
thats the reason that he can't get them to bleed

[humpy]

For all of you who do not know Hotwheels, he is a good friend of mine and knows his sh** about mini trucks and 4runners. He has also been a Toyota mechanic for about 6 or 7 years now. I talked to him last night and he has done everything you guys have mentioned several times and them some.

pfeer, humpy... I have seen many of these conversions done on the 1st generation runners and trucks as you have and they get done without any trouble. I also know a few guys that have done this on 2nd gen 4runner and had these problems. After talking to Rob(hotwheels) i think he has come to they conclusion it has to do with the 4runners that came with ABS.

So all that being said... I hope i have not made anybody mad or steeped on any toes. I am not directing this at onyone in particular. I just thought everybody needed to know that Rob is not a newbie or some one who does not know anything about toyotas...

I know everybody is just trying to help, but some just seem to be beating a dead horse...

Rant over... :D
:beers:
Chris

damn people must be sensative!!!! i did not take any personal shots just agreed that anyone of these setups that i have seen or done never had that prob...i dont know nothin from the next guy lol i just got welfare junk...only thing different that he has versus the old style may be the vacuum booster....try a non abs booster and see what happens...if that dont work ill give 100 bucks for it :D:D

[krawlin85toy]

Now get the d*** thing fixed so you can go wheeling .....:singingbev:

:beers:

x2
I also have a first gen runner with converson and no problems,but as said each toy has a different problem. The new runner i am diong may have same issue as hotwheels. I am glad to see if i do I can fix also.:sweatin:

[gothodgie]

damn people must be sensative!!!! i did not take any personal shots just agreed that anyone of these setups that i have seen or done never had that prob...i dont know nothin from the next guy lol i just got welfare junk...only thing different that he has versus the old style may be the vacuum booster....try a non abs booster and see what happens...if that dont work ill give 100 bucks for it :D:D


:party:

[Hotwheels]

damn people must be sensative!!!! i did not take any personal shots just agreed that anyone of these setups that i have seen or done never had that prob...i dont know nothin from the next guy lol i just got welfare junk...only thing different that he has versus the old style may be the vacuum booster....try a non abs booster and see what happens...if that dont work ill give 100 bucks for it :D:D

It has a non ABS booster in it right now.

[Hotwheels]

First, I had a very spongy pedal. I could easily hit the floor. Long before the tons went in. Used both abs and non-abs MC. Removed the lspv and same thing. Then I went to tons using the same rear 1/2 calipers in back with matching 1/2 ton calipers up front. Same problem. So I decided to try the GM swap. I spent way too many hours trying to decide between 1-1/8 vs 1-1/4. In the end it's such a cheap upgrade I thought it was best not to risk a pedal too stiff. If I wanted more it's just another 15 bucks.
Bingo! There it was. Now it's perfect. The pedal feel and brake grab is now closer to that of my car.

note: when we say bleeders on top, that means just that. The calipers should mount close to the 3 or 6 o'clock position depending on how you look at it. Bleeder right at 12. Anything else just won't do.

I did pull the top pin out and move the bleeders to 12 and still have the same spongy pedal.

[pfreer3]

So if its got a non-ABS booster, what is different? Are the circuits layed out different? Guess I don't understand what COULD be different, unless I look at the brake systems.... I have access to Toyota online FSM for your newer rig, and I have an old 87 manual somewhere. I'd like to know for my own reference.

Didn't mean to offend, you run into a lot of unknowledgable people on forums...:D

I'll kick back a response if I find anything out...

[Hotwheels]

There is no diference between an ABS and non abs booster. There are just dual diaphram and single diaphram booster. The difference is the master there are ABS MC and non ABS MC. your older 4runner and my 2 gen runner are not the same. I will have the bracket made and I bought a GM master today. As soon as to get them on I will let you know the out come.

[humpy]

so why not run the master off the older style runner???

[Hotwheels]

I am running the master with non ABS 1" bore that is the master that you have to run. Am older master are 13/16 bore.

[krawlin85toy]

quit worring about the brakes and just get lower gears!!!:evilgrin:
Just hurry up so we can go wheelin.:evilgrin:

[gothodgie]

quit worring about the brakes and just get lower gears!!!:evilgrin:
Just hurry up so we can go wheelin.:evilgrin:

:thumbup:

:party:

[humpy]

so has this thing been burnt to the ground yet or what???????? :D:D

[Hotwheels]

No, making the GM master cylinder plate hope to have it on Monday.

[Flxratd]

if that dont work see truggy for the needed boombooms to make the problem go away.:thumbup: he likes to blow stuff up.

oh and i hope this works, need to get out and wheel

[itbrokeagain]

I hate brake issues. Been trying to get good brakes for years. Everything that works for everyone else wont work for you when you try it.

[Hotwheels]

Got everything bolted up tonight at work going to bleed the brakes tommarrow morning.

[Hotwheels]

Well I got everything bolted up last friday at work but didnt have the time to bleed the brakes because they were kicking me out of work for the night. Today I got all the brakes bleed out with the GM master on my runner. This thing brakes great with the bigger master on it. The pedal is great and everthing is working fine. All I need to do now find out where I want to adjust the proportion valve for the rear brakes.