need help.........Is it only the Master Cylinder?

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toyotanorthny

toyotanorthny

10 Year 15 Year
Joined
Feb 16, 2009
Threads
16
Messages
96
Location
New York City
1999 LC with 135k miles on the clock


Today I had a scary situation. ABS and brake light came on along with an alarm. Drove 3 blocks to mechanic and almost lost control of vehicle. I used hand brake and managed to park on side of road.

Symptoms: ABS and brake lights on. Alarm sound coming from dash.
pedal travels all the way down with no power.
Brake fluid reservoir at normal level. No apparent leaks.

I have read many posts with various info, but nothing concise to answer the following questions:

-There are various components to the braking system. How does one test to see if it's the Master Cylinder only?
-If it is the master cylinder, what else should be replaced while servicing this part?
-Should I replace the accumulator and/or brake booster also? how can these be tested?

I can purchase just the MC for around $1400. If I need the booster and accumulator it doubles the price.

Any and all input is greatly appreciated as I would like to replace the non working parts only if possible.
Thank you all.
 
Make sure you get it diagnosed properly first and then determine a course of action.

Here's what happened to my vehicle last fall in the Mater Cylinder Rebuild thread.
 
Sounds like the booster failed, but it's easy to see/hear if it's running or not. Do your diagnosis before starting to swap parts.
Dealers normally just start swapping one expensive part after the other, until one out of two situations is true: A - the problem goes away by itself, or B - the customer is broke.
 
You're right about the dealers A and B way of doing things. I will check and see if booster is operational. I just wanted to know if the various components could be replace individually instead of the whole set up as my new indie wants to do.
 
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Does anyone else think these reports of complete loss of braking from a MC/booster failure is a serious problem? If all the failures were reported to the NHTSA, would there (eventually) be a recall on the brake Mc/booster? I plan to tow my camper through the mountains out west this summer and I have no interest in having a complete brake failure. Sorry for the rant, but I happen to think brakes need to be fail-safe. After a few more new threads like this one, I'm going to be wondering whether to keep the L.C.
 
^^^
I agree. This is a common occurrence on 98-99 models and maybe others. I am planning to replace the mc/booster soon. I don't trust it after reading about all the failures. Mine acted up a while back and then went back to normal.
 
I don't know - from what I've read, I'm inclined to think there are other, more common failures depending on the MY.

Mud is an enthusiast's forum, so whenever something goes wrong on these vehicles, it's going to get posted here first.

@toyotanorthny - Yes, the codes were read by an OBD II reader at AutoZone. The CEL came on as well. I had it repaired at an indy shop here locally that specializes in Toyotas and LCs. They had the appropriate equipment to verify what failed. Then I ordered the assembly from one of the Mud vendors.

@Sandroad - I don't necessarily disagree with you. But lacking good data, who knows? We were in the Swell the day before and if it had failed that day...it would have been some serious $$ to get us out of there. Even then, coming down the west side of I-70 though, we had a semi ride our tail until we turned north. I hate to think what would have happened if it had failed then as well.
 
What bothers me the most is the sudden complete lost of brakes. Thank God I was driving on a regular street at no more than 30mph. This speed enabled me to use the hand brake and come to a stop right in front of the 49th Police Precinct of all places. Just last week I traveled to CT in snow and rain, and just thinking if this had happened on the highway. I've read many posts here since this incident and noticed the obvious 98-99 models have this problem.
The tow truck operator informed me that I'am not the first to get tow for this problem. He mentioned a lady had the same exact problem on a street and she managed to crashed into 4 vehicles until she came to a full stop.
Makes me wonder if this is a problem that Toyota looked the other way in order to avoid a recall.
 
I had the same problem when I purchased my 99. Unfortunately, I believed the seller who said it "only needs a bleed" because he was on mud and he had all the rotors and disc replaced within a few months time frame, I figured he may be right. Nope, even after the brake bleed the alarm was on, limited pedal pressure, and poor to no braking. I pulled off the whole unit and tested brake booster according to info here. Booster was not working. Someone on the form had used a booster from a later year tundra or 4Runner but they did not respond to my request for info (they may have moved on from the form or got a new hobby). A few salvage yards had a similar booster, according to them, but when I ordered the part and compared it, it was a no go. I ended up dropping about $2000.00 for the new unit through a mud Toyota contact. It works great now but was an expensive lesson. Good luck.
 
NHTSA notification would definitely help in getting Toyota to step up. I encourage you to submit your comments.
 
It also sucks we have zero brake system redundancy (dual circuits). I found out the hard way if you lose one brake-wheel line, you lose all 4. Hard to believe in this day/age of automobile safety everything (past decade + actually) we do not have fail safe/redundant brake circuitry on our 100's. Jeez...even my old '69 3/4T Chevy PU had separate front and back brake circuits...
 
There is a redundancy. The MC piston is double, with an inner and an outer piston. The outer one regulates the pressure from the booster to the wheel cylinders. If there is no pressure in the booster, the inner piston will apply pressure to the front wheels only, but you have to push really hard to get any braking force.
There are actually four separate circuits on the newer models, and three on the earlier ones; but how this works in case of a blown brake line, or caliper, I don't know.
 
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It better be redundant. Federal law required redundant brake systems in 1966! The standard was usually a dual MC with crisscross pressure per circuit (front driver side, rear pass, and opposite).
 
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Called NHTSA yesterday and registered complaint. Thought about it and called back and asked how many complaints they've had registered. With mine, that makes 2 !!!
So guys, plenty of us have had this and comments on the design having redundancy are, IMHO, bs. I had maybe 5% stopping power from brakes upon failure. Downshift and e-brake were pretty much all I had.

Call and register your complaint on this system. Took me less than 5 minutes.
 
hold off on the class action lawsuit.....

I still have a single circuit in my 64 FJ45....if you loose a line or anything more than a slow leak you loose all the fluid in the system so there is no way the hydraulics can work even a bit. In a dual system, if you loose a front brake line, you still have fluid in the rear lines or visa versa(or in some cases, chriss cross)

that's it!

the parking brake is the redundancy....its called the emergency brake for a reason, they are always on a separate circuit(cable or whatever)

If the booster fails, there are still brakes....they are hard and at the bottom but they work.
If the master fails....you use the parking

I don't know what you expect.....little Toyoda Elfs to come out and stop you? :idea:

this explains it pretty well
http://www.kfz-tech.de/Engl/HydraulischeBremse.htm
http://www.kfz-tech.de/Engl/HydraulischeZwkrBremse.htm
http://www.kfz-tech.de/Engl/HauptbremszylZ.htm

and so on...


funny thing, last week I got yet another check for $29 from Toyota, this is the 4th I think....I have never bought a new toyota, my newest is 2000....but they send checks or some law firm does to get you to sign off on some class action or another that does not even effect me........so I keep cashing them ;)
 
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NHTSA. Class action or not. This sounds pretty Fning crazy. Last thing I want is to be driving with my family down some hill and have this go out. I would lose my $hit and either over react or I don't know what.

Common on 98-99??? Any data out there??

Issue rectified for newer models???

Not cool.
 
its not crazy! and there is nothing wrong with braking system, get over it. Its normal.

Whats not normal is the fact that you guys are freaking out over nothing. If your worried you may loose your brakes someday....thats a good thing, just be prepared for it.

cars are dangerous..... all kinds of bad things can and will happen.
 
Landpimp said:
its not crazy! and there is nothing wrong with braking system, get over it. Its normal.

Whats not normal is the fact that you guys are freaking out over nothing. If your worried you may loose your brakes someday....thats a good thing, just be prepared for it.

cars are dangerous..... all kinds of bad things can and will happen.
Click to expand...
WTF?
 
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