let's talk 80 series brake bleeding (1 Viewer)

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landcruiser3DP

landcruiser3DP

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any good posts on this?
i did 4X calipers and also the LSPV. i put in speed bleeders 5X so i just crack them a little and pump the brakes and then close them.
i started the bleeding procedure PS rear, DS rear, lspv, then PS front and DS front.
clear fluid in all five and the MC never got below half full.
the brake pedal is "spongy" and will be soft then medium then hard. but dort if not consistently.
also the ABS light is on.
any ideas on what i need to do?
also what is the reason i sm supposed to take it out on dirt and activate ABS exactly? is it that sir gets into the ABS lines and the main system will be spongy until you get it out?(!).

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read the ABS code. also do a gravity bleed on all corners for 10 min each not sure if you can do that with those "speed bleeders" you installed might have to put regular ones in. are all your calipers installed the right way with the bleeder facing up? are any of the hoses twisted? do you have any leaks? the reason to activate the ABS is that is possible to have air trapped in the abs valves and that can let the air come out. sometimes when you have an old master cyl and you push it further then it's been pushed (because your bleeding the brakes using your foot and the pedal is going lower then normal) it moves those old rubber seals into a more rusty rougher spot in the cyl and cuts up your rubber seals making the master internally bypass.
 
I will help. Pressure bleed is the only way I have found to get the air out

What you need
1). 1/2 gallon pump garden sprayer
2). 10 feet of clear tubing 1/2in iirc what ever fits your set up
3). One of these

4 ) empty bottle.

Configure the bleeder cap and weed sprayer, by removing the spray thingy and put the bleeder cap in its place.

Then put the bleeder cap on your master cylinder and pump up the weed sprayer that you have put at least a quart of fresh dot3 in.

Then with a clear hose on your bleed screw bleed into the clean empty bottle. Bleed bleed bleed, refill and bleed some more go all the way around at least twice and let good fluid flow run at least a few mins at each bleeder screw.

With this method I have gotten really really good pedal feel in every 80 I have had and the notorious gmt800 trucks. It takes a lot of dot3 but you will get there.
 
TheBussman said:
read the ABS code. also do a gravity bleed on all corners for 10 min each not sure if you can do that with those "speed bleeders" you installed might have to put regular ones in. are all your calipers installed the right way with the bleeder facing up? are any of the hoses twisted? do you have any leaks? the reason to activate the ABS is that is possible to have air trapped in the abs valves and that can let the air come out. sometimes when you have an old master cyl and you push it further then it's been pushed (because your bleeding the brakes using your foot and the pedal is going lower then normal) it moves those old rubber seals into a more rusty rougher spot in the cyl and cuts up your rubber seals making the master internally bypass.
Click to expand...
/thanks/ man. really appreciate that.
so i pull the code off my ultragauge?
then i go out and activate the ABS repeatedly?
then i get more brake fluid and gravity bleed all five in the order i listed?
then i'm looking at replacing or refurbishing the MC?
i think everything else checks out but i gather i need to get up under to check for any leaks first?
 
I also use a pressure bleeder and run it around 20 psi.

A few additional steps that I take:
  • As each individual circuit is open and letting fluid out I give the brake pedal short, fast pushes to possibly flush out trapped air bubbles with the rush of fluid.
    • Deep strokes into new territory can damage the MC seals as mentioned above.
  • I activate the ABS pump in the bleeding/flush process to help remove air/old fluid from the pump (see photo below).
  • After flushing all 5 bleeders I then will crack/loosen slightly the lines on the ABS pump. I do this since it may help eliminate air / old fluid in one/more of the lines/circuits. This is also a good way to run the last of the fluid out of the bleeder and get the fluid level in the reservoir down to the level where you want it since you can be standing/watching the levels closely.
    • Brake fluid is hygroscopic / bonds to water easily so, once you've done your fluid flush, gotten the MC reservoir level right and buttoned things back up you need to rinse the area around the ABS pump/MC well to remove any residual brake fluid. Brake fluid can melt paint so I typically pre-wet the area and then do the final step where I bleed the ABS lines quickly so that the brake fluid is on paint for a very limited amount of time.

80 abs pump activate.JPG
 
jpoole said:
I also use a pressure bleeder and run it around 20 psi.

A few additional steps that I take:
  • As each individual circuit is open and letting fluid out I give the brake pedal short, fast pushes to possibly flush out trapped air bubbles with the rush of fluid.
    • Deep strokes into new territory can damage the MC seals as mentioned above.
  • I activate the ABS pump in the bleeding/flush process to help remove air/old fluid from the pump (see photo below).
  • After flushing all 5 bleeders I then will crack/loosen slightly the lines on the ABS pump. I do this since it may help eliminate air / old fluid in one/more of the lines/circuits. This is also a good way to run the last of the fluid out of the bleeder and get the fluid level in the reservoir down to the level where you want it since you can be standing/watching the levels closely.
    • Brake fluid is hygroscopic / bonds to water easily so, once you've done your fluid flush, gotten the MC reservoir level right and buttoned things back up you need to rinse the area around the ABS pump/MC well to remove any residual brake fluid. Brake fluid can melt paint so I typically pre-wet the area and then do the final step where I bleed the ABS lines quickly so that the brake fluid is on paint for a very limited amount of time.

View attachment 3705852
Click to expand...
thanks a lot for this jp.
can i just ask if there is a link for jumpering the diagnostic under the hood to get the ABS code? i checked on my ultra gauge and it says no trouble codes and i am being told i need to jumper that thing under the hood that i use to set timing? but i don't have it printed out for my glove box and i don't know what search terms to use. THANKS
 
jpoole said:
Just did a quick search for "fzj80 pull abs error codes" (not in quotes when I searched) on Google and these links (among many others) came up and may be helpful:
Good luck.
Click to expand...
thanks a TON man.
i'm studying your other links now.
just one more for today which is i noticed a kind of intermittent scrap on the right rear wheel. it's was kind of hard to parse since i have new rotors and brake pads.
the e brake pads had plenty left on them so i left those.
but i noticed your first link said something about warped rotors so i mention it.
also i can report it only goes on when i am moving. so it doesn't go on with the key in the ignition. and it doesn't go one with braking. it goes on with moving.
i suppose i may need need to remove that rear wheel and reseat it?
anyway i will get on that code and close bleeding it again...

Dropbox

www.dropbox.com www.dropbox.com
 
The only way I’ve successfully bled brakes on any 80 especially with ABS intact is with a pressure bleeder. You will have to diagnose the ABS codes first and either fix it (if possible) or delete/replace the pump assembly if it has internal issues. Without running the ABS pump you have zero hope of getting a good pedal again. Also that master cylinder looks rough and probably would be a good idea to replace. It’s very very cheap insurance.
 
just in case anyone knows the process here but if i am tracking i can either get it up in jacks 4X, and slowly depress the brake pedal to activate (or purge i guess) the ABS system lines into the brake system proper? then i can crack each of my five speed bleeders a little and bleed each line one at a time?
/or/ i can do this electronic method that seems to involve grounding FIVE pins and applying the HOT Pole of my battery to the other TWO pins?
i'll post a better pic of that diagram here shortly.

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For one option you can go read my post above #5. I have the brake system under pressure then:
  • crawl under the truck and open the bleeder (running into a catch bottle, bleeders are greased/sealed on thread so don't suck air)
  • crawl out and then check the pressure on the bleeder bottle (I keep it around 20 psi)
  • hit the abs pump cycle for a few seconds (keep it wired up so you can just apply power)
  • hop into the drivers seat and short/fast pump the brake pedal a few times
  • crawl back under the truck and close the bleeder valve when enough fluid has run out for fluid to be clean/clear
I'm sure there are other ways to do this and you could add an abs cycle to the final step that I listed above where the lines on the ABS module are open (if you do that step).

There may be a "perfect" bleed process that get's all air and contamination out in minimal time but I'm not aware of it and the processes you are referencing above are "made up" to some extent and not "official" processes from Toyota. Since I don't know the perfect bleed method I follow the procedure I've listed above and I run a qt bottle (at least) through the system every year or two. It doesn't take long and my brakes have been consistent for years.

If you don't want to deal with the extra steps I've listed you can always drive around and cycle ABS then run another bottle through it until the system feels good :) As long as you aren't re-introducing air and all components are good you'll get the brakes tightened up eventually.
 
there is alot of good info here but just replacing the calipers "should" be pretty easy to bleed, usually I can bleed them with gravity alone. It's when you replace master cyl or ABS parts that it's more difficult to bleed (unless you reverse bleed) . not familer with ultragauge, not sure if it will read it or not.
 
So what changes when bleeding brakes with a deleted ABS/LSPV? I've been doing it my way but wanted to know if there's a special technique the gurus use
 
Speed bleeders are BS. The reason is that you need to generate enough pressure to overcome the resistance of the check valve.

Air compresses easily and it takes a large volume to create pressure and the check valve will close before all the air is purged.

Put stock bleeders in and do a traditional bleed.

Then with someone in the cab STANDING on the brake pedal with the engine running. Do another bleed. This will fully compress the air and slow you to purge the ABS system.
 
joxeale said:
So what changes when bleeding brakes with a deleted ABS/LSPV? I've been doing it my way but wanted to know if there's a special technique the gurus use
Click to expand...
What changes is bleeding your brakes is so much easier and you don’t have air or debris caught in the ABS module that you’re fighting. And you’re rewarded with much more responsive and better braking performance.
 
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