Another brake job

[cmiller114]

I've searched and read all the posts on 80 brakes.
I just finished replacing all four rotors, calipers and pads as well as rebuilding the e brakes....all Toyota parts. While bleeding the system, the pedal became very soft and would travel all the way to the floor with the bleeders closed. I checked all the soft lines and decided I must have blown the master cylinder with "over travel". I replaced the MC with a rebuilt Aisin from Advance Auto and have ordered a new one from T. My problem now is I have good pressure at both rear calipers and almost nothing on the fronts. This has to be a bad MC, correct or am I missing something here?

 

[superjuice]

did you bleed the lspv as well? That might cause those symptoms. If you let the resevoir run dry you may have also let air into the abs system which i hear is difficult to get out. hth

 

[superjuice]

Oops. Well obviously the resevoir went dry while changingd the MC. Not sure how to bleed the ABS but i beleive you need a tool from toyota to activate abs while bleeding. I sure someone with more knowledge will chime in.

 

[Ebag333]

If you need to bleed the ABS take it to the dealer. The dealer's price is usually around $100 or so, the SST to bleed the ABS is somewhere around $500.

Sounds like air in the lines to me.

 

[96r50]

I've searched and read all the posts on 80 brakes.
I just finished replacing all four rotors, calipers and pads as well as rebuilding the e brakes....all Toyota parts. While bleeding the system, the pedal became very soft and would travel all the way to the floor with the bleeders closed. I checked all the soft lines and decided I must have blown the master cylinder with "over travel". I replaced the MC with a rebuilt Aisin from Advance Auto and have ordered a new one from T. My problem now is I have good pressure at both rear calipers and almost nothing on the fronts. This has to be a bad MC, correct or am I missing something here?

Landtank had a similar problem (no front brakes, good rear brakes) that he started a thread about. I believe he tracked it down to a leaking front line that was letting in air but not leaking fluid. Search would tell the whole story in better detail than I can

Oops. Well obviously the resevoir went dry while changingd the MC. Not sure how to bleed the ABS but i beleive you need a tool from toyota to activate abs while bleeding. I sure someone with more knowledge will chime in.

If you need to bleed the ABS take it to the dealer. The dealer's price is usually around $100 or so, the SST to bleed the ABS is somewhere around $500.

Sounds like air in the lines to me.

I don't know where this "ABS bleeding" requirement is coming from, but IMO it is total nonsense. There is an ABS actuator SST, and it does have a bleed function, but it is for bleeding brake systems with hydraulic assist. The only thing it is used for on an 80 series LC is to check the operation of the solenoids in the ABS actuator. It has nothing to do with bleeding the brakes on an 80 series. More info here: https://forum.ih8mud.com/80-series-tech/328953-air-abs-pump.html

 

[Ebag333]

I don't know where this "ABS bleeding" requirement is coming from, but IMO it is total nonsense. There is an ABS actuator SST, and it does have a bleed function, but it is for bleeding brake systems with hydraulic assist. The only thing it is used for on an 80 series LC is to check the operation of the solenoids in the ABS actuator. It has nothing to do with bleeding the brakes on an 80 series. More info here: https://forum.ih8mud.com/80-series-tech/328953-air-abs-pump.html

What would the point of the SST having a bleed function on it, if not to bleed the ABS actuator?

Look at this thread. Several people report poor braking performance regardless of what they did (adjust the brake pedal, adjust the master cylinder, bleed like mad, etc) right up until the point that they went down to the dealer and bled the ABS actuator.

https://forum.ih8mud.com/80-series-tech/308004-spongy-poor-brakes-fixed-sort.html

That's very interesting. I didn't know there was a specific actuator tool for the Land Cruiser. Or maybe it's fairly generic among several Toyota line ups. Interesting that the dealer doesn't always think to do this first and I'm sure my dealer never did back when they bleed mine. I'll bet it's a pretty rare problem and possibly limited to the Land Cruiser, due to it's 4 wheel ABS, bypass line, LSVP combination, which is maybe why it rarely gets used.

As far as why no mention in the FSM. The FSM that we get as consumers is fairly limited already. I've seen technical manuals and documents posted on here from Toyota that are far more detailed than the standard FSM and also Toyota (like all manufactures) overlook or miss things, so they cover that by posting technical bullitons to dealers. I'd be interested to know if any technical bullitons have been posted on the Land Cruiser brakes and how to bleed them properly.

One thing about the 80 series is that it's a very rare vehicle. Less than 10-15K imported per year. Many dealers and mechanics may never even see one or not seen but one or two every few months or years. So, they may not have vehicle specific knowledge and experience with them.

Well it is sort of mentioned. Its in the section of testing ABS actuator but it is not part of the brakes bleeding step. But you supposed to test actuator anytime you do major brake job which means while testing you will bleed the ABS actuator.

So in twisted Toyota way that's what supposed to be done. I would love to see the wiring diagram of the tool or atleast voltages on the connector. I am sure tool can be replicated.
I posted dirty way of doing it (fooling abs sensors to trigger valves to open) but I would rather see a tool that can cycle them while truck is in park.

 

[96r50]

What would the point of the SST having a bleed function on it, if not to bleed the ABS actuator?

The short answer: That SST is used on a number of Toyota vehicles, some of which do require the bleeding function. The 80 series is not one of those vehicles, guaranteed. I bet you a beer.

The longer answer: I read this reply just before I left work so on my way home I stopped by the Toyota/Lexus dealership I used to work at. The head Lexus mechanic there is a very competent fellow, and from what others have told me, is one of the very top rated Lexus mechanics in Canada, among other things. I have consulted with him a number of times in the past about a variety of topics as I value his opinion and his knowledge, and I consider him a friend. Suffice it to say that there are only a few people with whom I would feel comfortable leaving my truck and trusting 100% in the work done, and he is one of them.

I discussed the use of this ABS actuator tool with him, including its use on our FZJs. He was familiar with the tool and knew right away which one I was talking about. He assured me that the only use for it on an 80 is to diagnose a faulty ABS actuator. It has zero use during the bleeding process. The bleed function, as mentioned above, is for certain vehicles (e.g. those with rear-only ABS powered by the power steering pump), and the 80 is not on that list.

I also read the brake section of the FSM when I got home and there is no mention of any SST or special bleeding requirements anywhere I could see.

Look at this thread. Several people report poor braking performance regardless of what they did (adjust the brake pedal, adjust the master cylinder, bleed like mad, etc) right up until the point that they went down to the dealer and bled the ABS actuator.

https://forum.ih8mud.com/80-series-tech/308004-spongy-poor-brakes-fixed-sort.html

I followed that thread as it developed (and I read it again just now). There was a lot of speculation and assumptions but I didn't see any facts that clearly demonstrated the use of the ABS actuator SST to bleed the brakes, or any improvements as a result. A couple members said they asked the dealership to use the ABS SST, but I'd be very surprised if that actually happened once the truck rolled into a work bay

 

[Ebag333]

I discussed the use of this ABS actuator tool with him, including its use on our FZJs. He was familiar with the tool and knew right away which one I was talking about. He assured me that the only use for it on an 80 is to diagnose a faulty ABS actuator. It has zero use during the bleeding process. The bleed function, as mentioned above, is for certain vehicles (e.g. those with rear-only ABS powered by the power steering pump), and the 80 is not on that list.

I also read the brake section of the FSM when I got home and there is no mention of any SST or special bleeding requirements anywhere I could see.

Okay, but if you are supposed to test the ABS actuator any time you do a major brake job (which might introduce air into the lines) then you are in essence bleeding it.

Really you shouldn't get air into the ABS actuator unless you open up the lines near it, or really really really try hard to get air into the lines. Even if you run the master cylinder dry you won't get air into the ABS actuator (at least not right away). I've tried.

I followed that thread as it developed (and I read it again just now). There was a lot of speculation and assumptions but I didn't see any facts that clearly demonstrated the use of the ABS actuator SST to bleed the brakes, or any improvements as a result. A couple members said they asked the dealership to use the ABS SST, but I'd be very surprised if that actually happened once the truck rolled into a work bay

With many people I'd probably agree with you. OTOH folks like Brian seem to be a little OCD when it comes to their vehicle, and if they are anything like me they didn't let it out of their sight. Maybe they can chime in.

But perhaps you'd like to explain why bleeding the brakes repeatedly (including with power/vacuum bleeders), adjusting everything possible, etc, no improvement was seen. Then they take it down to the dealership, ask them to use the ABS bleed function, and see immediate improvement. The dealer obviously did something that they were not capable of. Considering that many of the people who posted on that thread know thier stuff, I can't imagine what else it could be other than the ABS tool, the only tool that they did not have access to.

You offer no other explanation for the sudden (and drastic) improvement in braking, but insist that it cannot be the ABS. Well if it's not the ABS, then what else is it?

 

[96r50]

Okay, but if you are supposed to test the ABS actuator any time you do a major brake job (which might introduce air into the lines) then you are in essence bleeding it.

Really you shouldn't get air into the ABS actuator unless you open up the lines near it, or really really really try hard to get air into the lines. Even if you run the master cylinder dry you won't get air into the ABS actuator (at least not right away). I've tried.

From what I remember of reading the FSM last night, I don't recall it saying that testing the ABS actuator is required after a major brake job. If that were the case, are there guidelines as to what constitutes a major brake job?

With many people I'd probably agree with you. OTOH folks like Brian seem to be a little OCD when it comes to their vehicle, and if they are anything like me they didn't let it out of their sight. Maybe they can chime in.

But perhaps you'd like to explain why bleeding the brakes repeatedly (including with power/vacuum bleeders), adjusting everything possible, etc, no improvement was seen. Then they take it down to the dealership, ask them to use the ABS bleed function, and see immediate improvement. The dealer obviously did something that they were not capable of. Considering that many of the people who posted on that thread know thier stuff, I can't imagine what else it could be other than the ABS tool, the only tool that they did not have access to.

You offer no other explanation for the sudden (and drastic) improvement in braking, but insist that it cannot be the ABS. Well if it's not the ABS, then what else is it?

Sounds like we're all in the same club. I had to trade trucks with a friend the other night so I could get his winter tires put on, and I was more worried about my "baby" getting home than I was about getting to the garage in 12" of snow driving an F150 with slick summer tires. I want to be clear, my intentions are not to knock anyone for anything, I just want to clear up what I believe is a big misconception about brake bleeding on these trucks. I also don't want to be the next Sumotoy so please stop me if I start to sound like him. Please!

I still believe that the ABS SST is not being used in the bleeding process on our trucks, even after a few people have requested it. One thing I want to point out is that there is a lot of leeway between customer and mechanic. I am not saying this is always the case, but it has been known to happen. The vast majority of customers that walk into a dealership know nothing more about cars than "get in, turn the key and drive. Oh, and once in a while I have to put gas in the hole behind that little door". Sad, but true. The service advisor's job is to sell services to these customers. Some advisors are great and will only sell you the services you actually need. Some of them, not so much. We've all heard the stories "I took my truck into the dealer for an oil change and now I need $2500 worth of work done! What do I doooooo?" Similar situation with mechanics. Some of them will just do the basic job and kick the car out, and some will actually take the time to read the FSM if they have questions and to ensure they do the job right, especially if they've never done it before. All this is to illustrate is that simply because you asked that the service be done, doesn't always guarantee that it is done exactly how you requested.


I read the thread again and I only saw one person who reported an improvement after the dealership supposedly used the SST. I wasn't there so I can't surmise what happened, but is it possible the dealer tightened a loose connection or just did a better job of bleeding? Did the previous shop know about the LSP&BV and the requirement to bleed it? Maybe the dealer did and that fixed it. I dunno (and again, I'm not knocking anyone).

I don't mean to be nit-picky, but I haven't seen any specific evidence of a sudden/drastic improvement in braking directly and solely related to using the SST. All the evidence I have seen/read/heard/discussed points me towards believing that the SST's only use on our trucks is to troubleshoot the actuator. Some of that is from the Technical Articles on this site: Automotive Training and Resource Site. In the Brake series, articles 9, 10, and 11 all have info that is relevant to this discussion. I am still quite open to the possibility of being wrong about that and I will happily eat my hat (so to speak) if so.


This is probably more philosophical than technical, but something I wonder is why Toyota would equip their flagship vehicle, designed to drive to hell and back, with an ABS system that could essentially cripple it in the field? I think one of the things we all enjoy about these beasts is the ability to fix almost anything anywhere at anytime with limited tools so it seems odd to me that they would limit it like that.












pleasesayno,pleasesayno.... umm, did that sound to much like Sumo?

 

[Ebag333]

From what I remember of reading the FSM last night, I don't recall it saying that testing the ABS actuator is required after a major brake job. If that were the case, are there guidelines as to what constitutes a major brake job?

Well, ABS is part of the braking system and one would assume (perhaps incorrectly, or perhaps correctly based on the compentance of the mechanic) that the dealership would fully test the braking system any time they had to open it up.

But I did go by what RedTacoma said, I'm not seeing anything specific in my FSM.

All this is to illustrate is that simply because you asked that the service be done, doesn't always guarantee that it is done exactly how you requested.

I agree, and that is why I am extremely picky with who I let touch my vehicle and why I am standing there when they do so. If they will not perform the service I ask, the way I ask for it, then I will go somewhere else, period. I don't care if the tech thinks it doesn't need it, I have a reason for asking for it and regardless if it needs it or not I want it done, after all I'm the one paying for it.

This is probably more philosophical than technical, but something I wonder is why Toyota would equip their flagship vehicle, designed to drive to hell and back, with an ABS system that could essentially cripple it in the field? I think one of the things we all enjoy about these beasts is the ability to fix almost anything anywhere at anytime with limited tools so it seems odd to me that they would limit it like that.

Well, only a very small number of people seem to have had problems with it (if you believe what they report). It's very certainly possible that one could bleed the ABS system without using the tool, just it takes longer. I bled my master cylinder without doing the bench bleed or FSM procedure, but it took over 2 large bottles of brake fluid to get all the air out.

Mr. T has done some other things that has me scratching my head. Like where they routed the EGR pipe (right next to non-critical parts...like the main engine wiring harness).

Personally, I don't think that this would help 99.9% of people. But it seems plausible to me that it might help (certainly sounds reasonable), and I can't see any way that it would hurt. And even if it does nothing, it gets the person down to the dealership to have their brakes professionally bled. And if there's one thing I want, it's people out there with good brakes!

pleasesayno,pleasesayno.... umm, did that sound to much like Sumo?

It didn't right up to this line:

This is probably more philosophical than technical

 

[96r50]

Well, ABS is part of the braking system and one would assume (perhaps incorrectly, or perhaps correctly based on the compentance of the mechanic) that the dealership would fully test the braking system any time they had to open it up.

It would be nice, but when you are paid by the job and not by the hour, quantity over quality = more $ in your pocket. As well, in the FSM, the only time the SST comes into play is when there is a problem with the ABS system, at which point it is used to rule in/out the ABS actuator as the culprit. So if the vehicle still stops properly after a pad/rotor job, the technician isn't going to touch the ABS actuator.

I agree, and that is why I am extremely picky with who I let touch my vehicle and why I am standing there when they do so. If they will not perform the service I ask, the way I ask for it, then I will go somewhere else, period. I don't care if the tech thinks it doesn't need it, I have a reason for asking for it and regardless if it needs it or not I want it done, after all I'm the one paying for it.

X2. That's why I'm happy to help friends and family with their vehicles, as I know the job will be done right.

Well, only a very small number of people seem to have had problems with it (if you believe what they report). It's very certainly possible that one could bleed the ABS system without using the tool, just it takes longer. I bled my master cylinder without doing the bench bleed or FSM procedure, but it took over 2 large bottles of brake fluid to get all the air out.

Mr. T has done some other things that has me scratching my head. Like where they routed the EGR pipe (right next to non-critical parts...like the main engine wiring harness).

Personally, I don't think that this would help 99.9% of people. But it seems plausible to me that it might help (certainly sounds reasonable), and I can't see any way that it would hurt. And even if it does nothing, it gets the person down to the dealership to have their brakes professionally bled. And if there's one thing I want, it's people out there with good brakes!

Something else I noticed is that there is no "Hint: when installing new ABS actuator, use SST to bleed it" in the FSM. Usually Toyota is pretty good about including things like that.

If someone really thinks they have air in the ABS actuator that they can't get out, they should go find a safe place and get the ABS to kick in while they do half a dozen stops, and then go home and bleed the brakes again. That will recirculate the fluid through the actuator as well as the SST, and doesn't require the hassle of appointments and paying someone else.

I wholeheartedly agree with that last line though!

It didn't right up to this line:

 

[Ebag333]

Something else I noticed is that there is no "Hint: when installing new ABS actuator, use SST to bleed it" in the FSM. Usually Toyota is pretty good about including things like that.

I noticed the same thing...

The installation says:

INSTALLATIONInstallation is in the reverse order of removal (See page BR-57 ).
HINT:
After installation, fill the brake reservoir with brake fluid, bleed brake system (see page BR-4 ) and check​

for leaks.

Maybe Mr. T assumes that after physical installation (but before bleeding) the tech will go through the on-vehicle inspection (during which process it seems you do run the ABS actuator). Either way, it's not exactly clear but then again the FSM isn't specific on many things.

If someone really thinks they have air in the ABS actuator that they can't get out, they should go find a safe place and get the ABS to kick in while they do half a dozen stops, and then go home and bleed the brakes again. That will recirculate the fluid through the actuator as well as the SST, and doesn't require the hassle of appointments and paying someone else.

And that's exactly what RedTacoma posted as his poor mans ABS bleeding solution.

 

[96r50]

Maybe Mr. T assumes that after physical installation (but before bleeding) the tech will go through the on-vehicle inspection (during which process it seems you do run the ABS actuator). Either way, it's not exactly clear but then again the FSM isn't specific on many things.

In my understanding, you can't use the SST without fluid in the actuator as there will not be any effect on the brake pedal (which is how you verify the tests on the actuator). You might also burn up/damage the pumps and solenoids if they rely on the brake fluid for lube or cooling, but that is only my speculation.

It's true, the FSM has room for improvement in many areas. Imagine if the collective knowledge of this forum was allowed to edit the FSM. You would need a forklift to turn the pages!

And that's exactly what RedTacoma posted as his poor mans ABS bleeding solution.

He did, and while I agree that it could help, I don't see the actuator as being the big culprit it is made out to be (I've always liked the underdog though ). With the ABS off (e.g. during normal braking, and bleeding) the brake fluid flows through the actuator with no restrictions. So while bleeding, there is nothing mysterious and magical going on in there. The fluid will pump straight through. This is why the SST is not required to bleed the brakes (do we agree that the bleed function on the SST has no use on an 80?)

I'll try and start a thread explaining the inner workings of the ABS actuator as I have come to understand it. Most of the info will be shamelessly copied from those pdf's I mentioned earlier though! Oh god, I sound like Sumo again...

 

[cmiller114]

Gentlemen, it appears that you are both correct! I spoke with the service manager and veteran tech at the local Toyota dealership, also the largest in central PA. They were surprisingly open and helpful....maybe because I show up there driving my 40 from time to time. This is what I learned:
For normal brake service procedures it is not required to actuate the ABS pumps during bleeding....this includes calipers, master cylinder and LSP & BV.
IF, for some reason the ABS has been actuated with air in the lines, then the pumps should be actuated during bleeding. The tech suggested that a DIY guy unplug the ABS or unhook the battery during any brake work to avoid this possibility.
If you suspect air in the ABS pumps, you should ask the dealership to do a fluid exchange. All the fluid will be replaced with fresh, dry fluid, the ABS pumps will be actuated and all lines checked for leaks......and bleed the entire system by default.
Most DIY guys fail to adjust the booster, pedal freeplay and LSPV and/or have old or "wet" fluid in the system and therefore have loose or soft feeling brake pedals.
I'll be replacing my rebuilt MC with a new Toyota unit on Monday and I am seriously considering taking the 80 to the dealership (for the first time) for a total fluid exchange.

 

[Archaic Aeronaut]

Hi, may be way out in left field and have not checked my LX450 lately, but had an interesting situation on my F150 where I did a brake job and replaced front calipers. I actually was able to mix them up and put calipers on opposite sides. The short of the story is that the calipers are basically the same, I had to work at it, when it came to putting the brake lines back on, but it happened.

I bled the system and found the pedal soft. I checked and adjusted booter and master cylinder rod.

I was told a story by a hot rodder and checked. Sure enough the bleeders were on the bottom of the caliper. You can not bleed the system this way, because air is trapped in the top of the caliper.

Pulled the wheels off, exchanged calipers, voila bled and pumped right up. I'm sure there are enough of you going, "what an idiot", but if this story helps anyone, well I guess that are what forums are all about.

Getting ready to turn the rotors on my LX450 soon. Good luck.