Greg'sToy

So what is secret to getting the system bled right? I did search, and followed the bleeding order, includings the LSPV bled last.
The story-
My brakes we screwy since I bought the truck. The pedal would sink to the floor under light pressure, but would be ok if i gave them a quick hard pump first.
It got worse over time, so I bled and I bled, but never got them to be sactifactory.
I just recenntly replaced the master cylinder, and starting the bleeding all over again. They are at least 80% better now, but too occasionally do that sinking pedal stuff. I used a might vac, one man brake bleeder, and the tried and true method of having my hillbilly neighbor pump up the brakes while i worked the bleeder screws.
any gravity bleeding expert opinions out there? I never had any luck with the gravity bleeding in the past (i'm too impatient).

shovelhead

Have you checked and adjusted the rear brakes? This has a direct effect on the pedal height. It is generally easier to bleed the brakes with a good adjustment to begin with

dogdenii

Are you losing fluid at all?

I would check each wheel carefully and look for fluid. Veryify that your calipers are working correctly and that your wheel cylinders are working correctly. Once you have verified this, then I would begin the process of looking at your soft lines. If they expand while braking, it will cause a soft pedal. If they are dryrotted or brittle in the least, replace them.

LR
RR
LF
RF
LSPV

One you do all of this, if you still have a soft pedal then I would verify the adjustment on the Booster pin. This must be set correctly in order for the braking system to function properly.

To much adjustment, the brakes lock up when hot
Too little adjustment and the brakes are soft

Greg'sToy

let's see...i didn't check the rear brakes out, due to the e-brake works really good. no fluid is leaking out anywhere. the pedal isn't soft, it just doesn't seem to have any resistance whatsoever at times. the old master cylinder did this too, but much more. once the pedal drops down low, a quick pump brings them back to normal, and it will stay that way for awhile. luckily hard braking is fine, just when i'm easing into the brakes does it want to sink..

Greg'sToy

where is the booster pin? and do you know the adjustment?

dogdenii

E-brake or not - take the drums off and have someone verify that both pins are moving on each wheel cylinder. Trust me.

The adjustment is different depending on the depth of the master cylinder that it sits in.



Here is just a bit of info. It's on a cruizer but it applys. http://www.4x4wire.com/toyota/maintenance/brakebooster/

Mohamed

It's also called a master cylinder pushrod pin

Greg'sToy

ok...i'll take the drums off and see what's up with the rear brakes. i'm pretty sure there's movement in there, i could hear movement when the hillbilly was pumping like crazy on the brake pedal. He had a big smile on his face the whole time he was sitting there in the drivers seat!

Sparman

When you bled the lines each time did you have air in the fluid? As stated earlier, soft lines are likely culprits.

Slowrunner

I heard you bleed the LSPV 1st. Thats the way I did it with no problems. Fixed my sinking pedal.

Mohamed

THANK YOU!!! Finally someone get's it right, well almost right. The general principle in bleeding brakes is you bleed farthest to closest, therefore you order should be right rear, LSPV, right left, front right, front left. That is coming from me, a Toyota shop foreman that corrected me one night in class, and a tech that works at a Chevy dealer. Sometimes you don't even need to bleed the valve as long as you do a thorough brake flush.

Greg'sToy

the only time i saw air bubbles was the first time i bled them after changing the MC. I wish the pedal was just soft, it's scarey when it seems like it's not there at all.

dogdenii

Call Toyota and have them change their tech manuals if you are that thrilled about it.

I've personally always bled the LSPV last and I've never had a problem.

Also.... when I had my brakes reverse bled at the dealer, they did it this way as well.

Greg - Keep us posted

Greg'sToy

Will do! I should have some time to play in the brake fluid on Thursday & Friday this week..

dragon564

I had a seal on one of the caliper pistons start to fail on me....never did see any leaking fluid cause all the fluid that leaked by went to the pad and got burned up in the braking process.....some days the pedal was hard as a rock and braking was good others there was little to no pedal at all of course a quick pump and they would be back .... Check all the seals on each wheel and your soft lines...

Greg'sToy

I checked the calipers out last night, they are moving, not frozen, and not leaking. I also installed new pads, 'cuz they were getting a little low, not too bad though. I'm the 6th owner of the truck, and and don't know when anything was done. It's better to be safe than sorry in my book when it comes to brakes.
I did a gravity bleed of the entire system for about 90 minutes too. I bled them all at once, and got plenty of fluid from each bleeder screw. I closed them up in this order, LR,RR,RF,LF,LSPV. I have the cleanest brake fluid in Toms River! The fluid in the res. tank is almost clear.
Unfortunately for me, there were no hillbilly neighbors around to press the brake pedal for me, so I don't know if the soft lines are expanding/deflecting yet. Are there aftermarket SS lines available?
I ran out of time before getting to have a look see at the rear brakes.
the results- they are about 75 to 80% better, but still sink down almost to the bottom of the pedal travel when light pressure is applied, but only sometimes. They might even pass NJ inspection, depending on how the inspector applies the brakes on the brake machine. I'm due for inspection at the end of the month!
Stab them hard, and they are always right there, 100%. Seems to be worse when completly cold, but i could be imagining that.
The next chance I get, I'll be taking the rear drums off to see whats up back there..probably Thursday/Friday.

dragon564

Lots of places sell the SS brake lines...If you go that way which I would recommend going ..then you might want to think about get the the rear line an inch or two longer than stock.....It really does help with lifts and rear travel distance......Hasa the Master brake cyl been done.....you can leak by the seal in there and not leak external but the pedal would sink as fluid was allowed to return to the tank.....

kernel

Mine did the same thing. I went though three mc's before I ended up buying a brand new one, not remanufactured. That did the trick.

Greg'sToy

hey- had some success! I went over the rear brakes, all ok. did you ever hear of really loose front wheel bearings causing this problem? my bearings were sooo loose, felt like a bad ball joint on the passenger side. I tightened them up (but not too tight of course) and the pedal seems normal now....Believe It Or Not!.....I've got to replace both front axles soon, i'll take a real good look at the bearings at that time. the grease was still pretty clean though.

dragon564

Greg, that's a new one on me, who wooda thunk it