Soft Brakes

[19963.4lsr5]

Hey guys,



Hope you don't mind me chiming in but I have been dealing with these exact issues for the last 2 weeks. 96 3rd gen 4Runner. Rear brakes replaced, then the front calipers, pads, lines, the works. Pedal still went to the floor. Replaced with an OEM MC and same issue. Bled the brakes 10 times on all sides to no avail. Pulling my hair out as I have now dumped hundreds of dollars into chasing this ghost brake issue.



Anyway, I do recall seeing my ABS light come on once or twice like a year or so ago. I hate to have to dump a grand into chasing all these brake parts. Anyway, if I find anything with my system I will certainly post and let you know but I think I'm going to start looking at the ABS.



jasontrd

Are you one of the pedal pumpers Before opening a bleeder? If you don't have a pressure bleeder the safest way is to start with a gravity bleed. When you get a solid stream of fluid then the next step is to open the bleeder and then push pedal. Then close the bleeder and release the brake pedal. All pumping the brakes does is take a few air bubbles and turn them into a million bubbles

Some here will tell you not to push the pedal all the way to the floor........I've never experienced ruining a master cylinder pushing the pedal all the way to the floor. So that on you to decide. My FSM's say nothing about not pushing the pedal to the floor during a bleed procedure.


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[Vansnxtweek]

Are you one of the pedal pumpers Before opening a bleeder? If you don't have a pressure bleeder the safest way is to start with a gravity bleed. When you get a solid stream of fluid then the next step is to open the bleeder and then push pedal. Then close the bleeder and release the brake pedal. All pumping the brakes does is take a few air bubbles and turn them into a million bubbles

Some here will tell you not to push the pedal all the way to the floor........I've never experienced ruining a master cylinder pushing the pedal all the way to the floor. So that on you to decide. My FSM's say nothing about not pushing the pedal to the floor during a bleed procedure.


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I guess I've always done it the way you are describing not to do it. Never had an issue on another vehicle. Is the 4runner different for some reason?

Just trying to learn. Thanks for the advice.

 

[19963.4lsr5]

I guess I've always done it the way you are describing not to do it. Never had an issue on another vehicle. Is the 4runner different for some reason?



Just trying to learn. Thanks for the advice.

I played holy hell bleeding the brakes on my 94 Ram many years ago. It was my first abs vehicle. So I opened up the FSM and read the procedure. Sure enough I had tiny air bubbles everywhere and pedal would slowly go to the floor. Let it sit overnight and did it by the FSM.......Bam. Done and all was good.

I still do a second bleed a few days after the first to catch any air that found its happy place after the component replacement and main bleed. I usually open each bleeder every year to see if any air comes out and to help prevent the bleeders from rusting in place. And when it starts turning brown I do a purge. My new fluid of choice is the synthetic DOT4.


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[jasontrd]

calipers on the correct side? bleeder on TOP?

Yes the calipers are on the right sides.

Are you one of the pedal pumpers Before opening a bleeder? If you don't have a pressure bleeder the safest way is to start with a gravity bleed. When you get a solid stream of fluid then the next step is to open the bleeder and then push pedal. Then close the bleeder and release the brake pedal. All pumping the brakes does is take a few air bubbles and turn them into a million bubbles

Some here will tell you not to push the pedal all the way to the floor........I've never experienced ruining a master cylinder pushing the pedal all the way to the floor. So that on you to decide. My FSM's say nothing about not pushing the pedal to the floor during a bleed procedure.

I did what I have traditionally done. Helper sits in drivers seat, I loosen bleed valve, they press pedal to the floor, I tighten, they release.

jasontrd

 

[jasontrd]

I think I'm in the same boat, air in the ABS pump somewhere. I've NEVER heard my pump run, nor has it activated in the 11 years we've owned the truck... and the brakes have always sucked, regardless of how many bleeds/components are thrown at it.

Now that you mention that I don't hear my ABS pump and I recall I used to hear it. It's not my daily driver so she just sits unless I'm going on a camping trip or hauling a trailer.

-jasontrd

 

[19963.4lsr5]

Yes the calipers are on the right sides.







I did what I have traditionally done. Helper sits in drivers seat, I loosen bleed valve, they press pedal to the floor, I tighten, they release.



jasontrd

+100


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[pluton]

Yes the calipers are on the right sides.
I did what I have traditionally done. Helper sits in drivers seat, I loosen bleed valve, they press pedal to the floor, I tighten, they release.

jasontrd

Isn't it: Helper sits in drivers seat, presses pedal, you open then close the valve, observing the fluid, helper presses again, etc.??
If you open the bleeder before the helper pressurizes the system, you allow air up into the lines before you start.

 

[99Runnr]

If you guys are all suspecting ABS to be a culprit, an have spent hundreds on parts that didn't mend it, perhaps it IS worth going to the dealership and utilizing their equipment (I'd imagine it's specialty for the ABS system) to get around the ABS nonsense. Give the dealer a call and ask, can't hurt if you guys are at wits end.

Never had an issue with ABS crap personally, an my 4runner is free of that garbage lol. Otherwise, my advice for bleeding brakes has always worked excellent for me.

Do not pump the pedal, one push, hold, crack bleeder open and CLOSE before the pedal hits the floor. Keeping constant expulsion of fluid. I give it 3-4 purges of bubble free before moving to the next wheel. Start passenger rear, driver rear, passenger front, driver front. I use Valvoline DOT4 synthetic. I go through it completely, drive it a couple days, then go over it once more and my 4runner pedal feels wonderful an it stops hard. Great time to do Tundra brakes since you definitely want more shit to worry about

 

[Vansnxtweek]

I played holy hell bleeding the brakes on my 94 Ram many years ago. It was my first abs vehicle. So I opened up the FSM and read the procedure. Sure enough I had tiny air bubbles everywhere and pedal would slowly go to the floor. Let it sit overnight and did it by the FSM.......Bam. Done and all was good.

I still do a second bleed a few days after the first to catch any air that found its happy place after the component replacement and main bleed. I usually open each bleeder every year to see if any air comes out and to help prevent the bleeders from rusting in place. And when it starts turning brown I do a purge. My new fluid of choice is the synthetic DOT4.


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I hear ya on that. I'm gonna go ahead and review the FSM and see what I find. Gonna be putting on the SS lines next week so it'll be a no-choice time to be bleeding the brakes. We will see.

 

[nevada]

lol.

i know. it seems like a ridiculous thing to ask, but I have seen it too many times for it to not be the first thing I think of.

 

[nevada]

Are you one of the pedal pumpers Before opening a bleeder? If you don't have a pressure bleeder the safest way is to start with a gravity bleed. When you get a solid stream of fluid then the next step is to open the bleeder and then push pedal. Then close the bleeder and release the brake pedal. All pumping the brakes does is take a few air bubbles and turn them into a million bubbles

Some here will tell you not to push the pedal all the way to the floor........I've never experienced ruining a master cylinder pushing the pedal all the way to the floor. So that on you to decide. My FSM's say nothing about not pushing the pedal to the floor during a bleed procedure.


Sent from my iPhone using Tapatalk

correct, one pedal push per bleeder opening. multiple pumps will make the job much harder.

 

[jasontrd]

Isn't it: Helper sits in drivers seat, presses pedal, you open then close the valve, observing the fluid, helper presses again, etc.??
If you open the bleeder before the helper pressurizes the system, you allow air up into the lines before you start.

Usually fluid comes out even before they press so I'm not really sure on that. I've always done it this way and it worked great every time.

-jasontrd

 

[jasontrd]

If you guys are all suspecting ABS to be a culprit, an have spent hundreds on parts that didn't mend it, perhaps it IS worth going to the dealership and utilizing their equipment (I'd imagine it's specialty for the ABS system) to get around the ABS nonsense. Give the dealer a call and ask, can't hurt if you guys are at wits end.

Never had an issue with ABS crap personally, an my 4runner is free of that garbage lol. Otherwise, my advice for bleeding brakes has always worked excellent for me.

Do not pump the pedal, one push, hold, crack bleeder open and CLOSE before the pedal hits the floor. Keeping constant expulsion of fluid. I give it 3-4 purges of bubble free before moving to the next wheel. Start passenger rear, driver rear, passenger front, driver front. I use Valvoline DOT4 synthetic. I go through it completely, drive it a couple days, then go over it once more and my 4runner pedal feels wonderful an it stops hard. Great time to do Tundra brakes since you definitely want more shit to worry about

I have a local mechanic I trust that I will bring it to as a last resort. The blue book value on this thing isn't real high so the more I stick into it the less I will get out of it but regardless I will not sell something that is not in good working condition and the brakes are absolutely critical of course.

-jasontrd

 

[Vansnxtweek]

Does anyone happen to have a link to the bleeding procedure in the FSM? I am ordering a FSM manual but would like to go ahead and review that if possible. I had found all the links I needed back when I did the head gaskets in January but I can't seem to find that link now

Thanks

 

[jasontrd]

I have a local mechanic I trust that I will bring it to as a last resort. The blue book value on this thing isn't real high so the more I stick into it the less I will get out of it but regardless I will not sell something that is not in good working condition and the brakes are absolutely critical of course.

-jasontrd

So I had my dad come over and repeated my bleeding procedure on the front and rear again. Same procedure: I loosen, he pushes to floor, I close the bleeder, he releases. I did this slowly and methodically until I had a good half cup of clear brake fluid from each brake and low and behold the brakes are finally working fine. Clearly there was still air in the lines even after the original bleeding processes. Anyway, not sure why it took so many tries but it is good.

I will also note that the booster check valve was working fine (check manually by blowing and trying to suck air through it) and the booster was clearing in working condition since I did not have a hard pedal indicating the booster diaphragm may have been bad. With the new MC I also did their bleed procedure with the included hoses before I put that in. Thank you all for the helpful suggestions. Very much appreciated.

-jasontrd

 

[stever1000]

My new brake hoses and master cylinder arrived at my PO box so I will pick them up next week and get them installed

In the meantime it seems like I over adjusted the rear brakes a couple weeks ago because my fuel economy went downhill.

 

[Vansnxtweek]

I just wanted to post to let everyone know what my issue ended up being. Rear brake adjustment, without a doubt. The shoes weren't even touching. I got those adjusted correctly and I have some pedal now! Feels way way better. Thanks to everyone for the advice.

 

[catrains]

I just wanted to post to let everyone know what my issue ended up being. Rear brake adjustment, without a doubt. The shoes weren't even touching. I got those adjusted correctly and I have some pedal now! Feels way way better. Thanks to everyone for the advice.

on brake drums , the drums wear out so the radius of the drum does not match the shoe radius. if YOU remove the drums and see that the top of the shoes are only wearing , then the drum is worn and will cause weak braking in the rear and also parking brake will also , not work good.

if the shoes were not adjusted to the point that they did not touch the drums then that is weird ,,, the brake cylinder could be damaged then leak,
drum IMO is too worn for that to happen.

 

[stever1000]

on brake drums , the drums wear out so the radius of the drum does not match the shoe radius. if YOU remove the drums and see that the top of the shoes are only wearing , then the drum is worn and will cause weak braking in the rear and also parking brake will also , not work good.

if the shoes were not adjusted to the point that they did not touch the drums then that is weird ,,, the brake cylinder could be damaged then leak,
drum IMO is too worn for that to happen.

I noticed on my passenger side shoes, the top right, top left, and bottom left were all the same thickness, however the bottom right was worn more than the others... does this mean my drum is worn as well?

 

[catrains]

I noticed on my passenger side shoes, the top right, top left, and bottom left were all the same thickness, however the bottom right was worn more than the others... does this mean my drum is worn as well?

if the bottom of the shoes are worn can be the park brake cable sticking .. bottom is park brake.. top is the brake cylinder..

lift wheel off ground and work the park brakes see if the rear wheel is free with park brake off position , and you hear no noises..