My 1999 LC ABS/BRAKE lights just lighted with a continuous sound. How do I trouble shoot this and if I need to replace parts which one? No leaks under, fluid level looks ok...HELP!!!
ABS/BRAKE lights and loss of brake
- Thread starter PinoyLC
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Well known issue. The booster pump has probably failed. Do a search to find all the threads detailing it.
- Thread starter
- #3
Sent you a PM. I have new and used 100 series brake system parts for sale (new OEM MC/brake actuator, used brake booster with accumulator, used master cylinder).
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- #6
what do you mean AFTER EVACUATING BOOSTER and which LEVEL is it? could you be more specific and easier for me to understand, I'm not too mechanically inclined with the lingos, Sorry and Thank you
To check brake fluid level there is a procedure which is done with vehicle on level ground. If you look on top of the reservoir, you'll see this procedure written out.
What it states is with key off/out pump brake pedal 40 times. This evacuates booster pump/canister which is holding brake fluid, into the reservoir. Once booster is evacuated, check to see that brake fluid is at the max line (not over or under).
As you can see fluid is at top max line, which is maximum it should be at. The max line is about 4mm wide, it can at bottom of max line.
Now that we've followed procedure to check level, we time how long it takes booster pump/canister to fill back up. Simple turn key to ON and time how long booster pump runs. You'll see brake fluid in reservoir drawing down. I do not starter engine for this test, as it would make hearing the pump more difficult. It should take 30 to 40 seconds for a health system until booster pump stops. More time could indicate system has air, so bleed and re test. If all air bleed out and still running longer or short, something needs fixing.
You can see booster pump drawn down the fluid level to halfway between max & min lines. Had this reservoir been low after level check (evacuating booster) it may have drop below min line as booster canister filled. Below min line will activate alarm.
Keep in mind that brake fluid level is based on new brake pads & rotors. That level will drop a little bit as pads & rotors wear. So it is ok to be a little below max. If topped when pads & rotors are worn, installing new pads & rotors may put over max line. Running over max is not advisable.
You should never have to add fluid, unless flushing. Needing to add may indicate leak.
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- Thread starter
- #8
WOW! Thank you for Illustrating and having the time to explain it, I have a clearer and better understanding of what to do and HOPEFULLY, zero in to the problem. Happy New Year and Live Long and PROSPER!
uHu
Bridgeburner
2001LC, you are really doing a fantastic job on this forum. Your posts help to bring us to a very high level as a technical LC forum. Your standards, presicion, thoroughness, willingness to help, are high above what most of us manage.
Sorry, but someone had to say it.
Hijack over.
Good luck to the OP. It will be interesting to see the cause of the problem, and the solution.
Sorry, but someone had to say it.
Hijack over.
Good luck to the OP. It will be interesting to see the cause of the problem, and the solution.
- Thread starter
- #11
You should run for public office, hardly do you see people extend kindness, share passion...thanks again Bro!
If the fluid is above the max line, can suck some out the reservoir?
Thank you @uHu that means a lot, especially coming from you!
Your welcome again. Just hope it helps! Keep in mind above is only start of evaluating brake system.
You can just suck it out or reservoir, A very thin hose is needed to get past stop under cap. A better way is bleeding off some by depressed brake pedal, key on (runs booster pump) than bleed a rear bleeder. I say rear because you can drain as much as you want without pumping pedal. Just don't empty revoir. For fronts you'll need a helper to pump pedal and hold, only getting a little at a time. By bleeding off a little rather than sucking out of reservoir it gets some of the nastiest old fluid out of calipers. Caliper is where heat is generated boiling the brake fluid, and attacking the most moisture.
I use and old shower curtain spring loaded bar to push on brake pedal, using seat motor against headrest with a protective rubber feet and a rag to protect leather of seat.
As always make sure you keep bleed caps on all bleeders and in good condition. They last about 7 years. If bleeder is not kept sealed moisture will damager bleeders and calipers.
I like to blow out bleeder as final step after torque in. This helps me in two ways: 1) Keeps from getting false visual inspection for leak. 2) Any brake fluid remaining in bleeder will attract moisture.
This bleeder rusted shut from bad or missing cap. I really can hardly believe how many shops don't replace bad caps after a brake job. Guess they know it insure a bigger more expensive job next time as they are incompetent.
First thing to check is if your pump it actually working or just given up the ghost. Pointless bleeding anything if it is unserviceable. Unless your below the minimum you should be fine, the brakes should work without a alarm sounding. Just turn the key and see if the pump runs, time the run time if it runs like @2001LC explained. Be prepared to be replacing some parts though, you might need some of them parts @NHouston is selling, I am not saying buy them from him as I don’t know who he is but they will be what your looking for.
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- #15
I already talked with Nhouston, he has the USED parts that I think I need but lm looking for a refurbished one just to feel more at ease. Thank you Julian!
I decided to check my break booster as described above. I also recently had an indie shop bleed the fluid before i checked the system. I provided toyota break fluid, and two bottles were used.
I pumped the break pedal 40 times. I noted the fluid was about a quarter of an inch to half an inch above the max line. I used a turkey baster to suck the fluid out, until level with the max line. While doing this and squeezing the rubber piece of the turkey baster to create suction, i created some air bubbles at the top of the break fluid reservoir. Do i have to worry about air in the system know?
After i removed the extra fluid i turned my key, and timed the break pump motor. I endrd up with 35sec. With a few pauses by the motor during the process.
I pumped the break pedal 40 times. I noted the fluid was about a quarter of an inch to half an inch above the max line. I used a turkey baster to suck the fluid out, until level with the max line. While doing this and squeezing the rubber piece of the turkey baster to create suction, i created some air bubbles at the top of the break fluid reservoir. Do i have to worry about air in the system know?
After i removed the extra fluid i turned my key, and timed the break pump motor. I endrd up with 35sec. With a few pauses by the motor during the process.
No worries @Drogon. Two things of note: As I recall the Toyota brake fluid comes in a small 16oz can, which would not be enough to thoroughly flush system. Second the fact you had to adjust level, indicates your shop doesn't know our rigs.
Make sure you get out on dirt, snow or ice road and stomp on the brakes to activate the ABS at least three time in a row. This pushes out old fluid with new through ABS valves. You can bet the shop didn't use techstream to do this, so this manually activating ABS is second best.
Sorry @PinoyLC thread has kind of gotten away from your issue. Did your fluid level and booster check out?
Keep in mind those are just first steps in checking out your brakes.
Make sure you get out on dirt, snow or ice road and stomp on the brakes to activate the ABS at least three time in a row. This pushes out old fluid with new through ABS valves. You can bet the shop didn't use techstream to do this, so this manually activating ABS is second best.
Sorry @PinoyLC thread has kind of gotten away from your issue. Did your fluid level and booster check out?
Keep in mind those are just first steps in checking out your brakes.
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- #18
Happy New Year Guys! I recently changed my Booster pump with a refurbished one and it seems its working well since I can hear it making a sound. Now, I see bubbles from my reservoir everytime I pump the brake pedals when we were bleeding it? The bleeding process went fine and NO AIR as far as I know. Does the bubbles means there still air in the system? and while giving it a few 5-10 pedal pumps the ABS-BRAKE lights on and then disappear when the booster starts to kick in? Could you please tell me what else to look into?
Hi i am having trouble with abs light on amazon 4.2, came up with abs pump motor replaced with brand new genuine. still no good lol, when you start the vehicle after about 10 minutes the abs light comes on ???? any help guys as i am struggling
^^ Can you pull the fault code?
