Hello all,
This is my first post on the site, and I guess it was worth a shot to see if fellow Acura owners have ever experienced anything like this before.

I purchased my 2002 TL Type S about two years ago. It currently has just over 100,000 miles. When I purchased it (88,000 miles) I noticed a soft brake pedal and vibration in the brakes. Anyone would agree soft pedal would be air in the lines or a bad O ring in the master cylinder; and vibration is bad pads, bad rotors.

I have a lot of mechanical experience, so I made it an afternoon project and replaced all 4 corners - rotors and pads.
I gravity bled and pressure bled the entire system brake system as well, and went through a full bottle of DOT 3 brake fluid.

2 months later --Still an issue. Replaced the master cylinder and re-bled the entire system.
The auto parts store informed me the masters are all "refurbished" and potentially could be a bad master, so I replaced it again. Bench bled it, and re-bled the car. No help.


I am still currently having the same problem. I decided to take it to the Acura dealership. They said it could be a problem with the brake-booster, master, or ABS modulator. I tested the brake booster, and it seemed fine. It holds pressure when pumped (car off), and then when the car is started it slowly releases. If the brake is pumped numerous times while the car is on it builds pressure, and if I try to do a panic stop right after sometimes its slow to

Since I have had the car I have never gotten any "Brake" or "ABS" light.

The softness of the pedal can sometimes fluctuate depending on outside temperature and driving conditions.
Today (20 degrees) it felt like there was an enormous amount of play in the brake pedal before it would actually engage the brakes. If you apply some damn good pressure however, it does stop normally.There was maybe 3/4"-1" between brake engagement point and the ground out point where the master cant go any further. Other times, the pedal engages all the way at the top and I get full-firm braking. I can definitely tell it has something to do with vacuum pressure....


Sorry this post is so long, I am just hoping by providing any information I can may help me find a solution faster.

Any thoughts?

Thanks for reading.

 

welcome to acurazine--
we have a good DIY section, 3rd item down the main thread list

basically- how did you bleed the brakes? whats gravity--letting it drip out??

the ONLY correct order for the TL is different than most cars.

Start at driver front, call it LF or left front, do it till good
then move to RF, next RR, finally LR left rear
clockwise around the car, should take between 7/8 and 1.5 qts
the order is due to ABS plumbing-not like old school cars of farthest first

A 1 person method with a suction/vacuum tool works well,
or
many do a 2 person: with helper doing 4 pump and hold- you open bleeder -they push pedal down- close bleeder yadayada you know how to do this

Important- for master cylinder protection: if helper not experienced enough to stop pushing and hold pedal at 3/4 pedal travel:
Place a block of 2x4 wood under the brake pedal arm to limit its travel to 3/4 of the way to the floor
Its normal range of travel
When the oring is moved past the normal range it can be damaged
new ones or old crudded ones are most at risk!
(from your description thats not your problem)

Also- when you have opened the brake lines to replace the master or a caliper
you MUST go do 2 `ABS active` stops from 45 mph

that means brake pedal shuddering under your foot,
Do a full brake effort and quick steering turn - as in accident avoidance on poor surface-lane change and back (everyone has seen the tv commercials)
that should get it working hard from the abs pump- thats what we want

Find a place with water or dirt, throw water on the street--but get one side of the car in different traction so the wheel speeds wont match
The procedure: In a safe place
Do a full effort- both feet buried on the brake pedal--from 45 to total stop with abs activated-
accellerate to 45mph and repeat to full stop

IF the 2nd test has better pedal--firmer- you had air trapped in the ABS controller
That procedure moved it out and to a caliper-
rebleed entire system in LF RF RR LR and test drive
(expect bubbles in LF but do all of them to be safe)

Thats info from the acura repair manual and not common knowledge to non acura repair places

this post was written with noobs to acura and repairs in mind, no intention to demean any posters skill level or knowledge with the extra details...

 

Thankyou, I appreciate the reply. I was aware of all of this because I have been working on cars for a very long time. I know there is no air in the lines. I have made sure of that time and time again.

 

To elaborate more on what I just said, the pedal has feedback always, and it has never had a problem stopping. When there is air in the lines it feels like you can press down on the pedal all the way, but nothing happens. If you hit my brake pedal it stops, fast. The pedal feel just sometimes feels lighter, and less firm. I drove a friends Acura TL- S tonight. The brake pedal was responsive and very firm. When I pressed the pedal (somewhat firmly) there was an immediate tire screech, and the wheels locked up. Mine, for some reason, does not react the same way. Its not as sensitive to my pedal pressure, and does not want to stop as abruptly and quickly.

 

his ABS is not working if the wheels locked up

did you do the 2 ABS active stops from 45 and rebleed the system on your car?
if wont give up its air until you do

 

I have tried this before, yes. I am going to take back the master, and get a brand new one this time. I am also replacing the shitty rubber brake lines with stainless steel ones. I know this is going overboard, but I just want this sloppy pedal fixed already. I am going to re-bleed everything exactly how you said, and hopefully this will fix everything.

 

And thankyou for taking the time to reply, I appreciate it

 

Great idea on getting a new master cylinder. I've had such bad luck with remans that I don't buy them anymore. Make sure you "bench bleed" the new one prior to installing it. Don't skip this step or you'll spend an eternity trying to bleed it on the car. Doing a few abs stops as 01 mentioned is just as important. With a good master cylinder and a proper bleeding, you won't even need the ss lines. They are a nice addition,tho.

 

SS lines improve pedal feel--just watch the rubber line swell when helper is pressing brakes to build pressure

the book- and car- require the 2 ABS stops as directed- following that procedure - not one of your own

sidenote- SS lines require DOT4 fluid

 

Just asking...Why?

 

Require- ? Because the boiling pt. of DOT 4 fluid is higher than DOT 3? DOT 3 shouldn't harm them.

 

I was told by ones smarter than me- use DOT4 with SS lines,,beyond the differances in the fluids- its one of those things I believe
dont have the tech reasons on hand at this hour~

 

DOT 4 and DOT have a similar makeup...DOT 4 has a slightly higher boiling point (not high enough for us racers, tho')

Some varieties absorb less moisture (like Castrol LMA (Low Moisture Absorption).


http://en.wikipedia.org/wiki/Brake_fluid
says that most cars in the USA specify DOT 4, post-2006, anyway...

 

newer spec- better fluid, most places sell stuff that says meets dot3 dot4 spec, so its dot4
dot/DOT means Dept Of Transportation = US govt agency rules/standards

racers can use five point one 5.1
but never 5.0 thats got silicones that kill us

 

bumpy bump..wow...im so lost.. 01tl4tl .. great insight..i have to read that over when im not falling asleep..so tired..

but my brakes locked n i lost half my bumper in a war with another acura ... y did it lock idk..i guess previous owner didnt do the 2 abs stop thing...

 

Have anyone cleaned the ABS Filter located in the ABS Pump?? Its a little cover on top of it that says "DOT 3 / DOT 4" the Manual call it "VSA Modulator Fluid Replacement" but its most likely a Reservoir for the ABS Pump, Anyway it has a Filter and it can be ugly.

I did it yesterday and its very simple!

MINI DIY:

1.- Grab a 5mm Socket and Remove the 2 screws.
2.- Take out the Shimming cover (Beneath it there will be a Rubber Gasket)
3.- Now with a syringe suctionate 1/2 of the brake fluid on the Reservoir (Leave some You dont want Air on the ABS pump)
4.- Take out the Plastic cover on top of the Filter (Clean this Cover!)
5.- Take out the Filter its a Plastic Mesh like some 1cyl Motorcycle Filters (Clean It!)
6.- DRY Out everything very well You dont want Water with the Brake Fluid!!
INSTALL:
1.- Put back the Filter and the Plastic Holder on Top of it!
2.- Now fill it with brand new Brake Fluid in my Case some Motul DOT5.1 until it drops a little out of the reservoir.
3.- Put back the Shimming cover & Gasket.
4.- Carefully Torque to > 3ft-lb < can be hand done or use a torque-meter for peace of mind FOR GODs SAKE DONT OVERTORQUE! those screws can and they WILL Strip with little force..
5.- ENJOY!

Just for the Record I had Brand New Brake Fluid on the Car but the thing is that the Filter will still get dirt over time, Remember that its a 10yr Old Car by Now... Hope it Helps!

 

DOT 4 has a higher boiling point both wet and dry, however it is not as hydroscopic as DOT3.

Boiling points are as follows:

DOT3:
Wet-284
Dry-401
DOT4:
Wet-401
Dry-446
DOT5.1:
Wet-356
Dry-500


DOT 5 is not glycol based, therefore its not hydroscopic...Glycol based fluids are not generic, they can be made with up to 10 different ingriedients with different blends, thus making up the differences between DOT3 and DOT4.

The 4 primary ingredients in brake fluid:

A lubricant- to keep moving parts sliding freely
A solvent diluent- Determines the fluids viscosity and boiling point.
Modifier Coupler- Changes the amount of swelling of rubber parts that come into contact with with the fluid.
Inhibitors- To prevent corrosion.

 

I posted this in another thread, but ignore that one. I prefer it to be in this one.

Is it me, or does the ABS modulator/pump on the 1999's (or all years without VSA) not have an accessible plate cover to change the fluid in it? See page 19-192 in the factory service manual.

The ABS pumps are like page 19-103 for the 1999's, while years with VSA have what's on page 19-191 correct?

 

you might have a bad abs unit with an internal leak
i had an accord that i bled the brakes and went through 3 big bottles of brake fluid
new master
still has a soft /low brake pedal
but the car stops normal
i know that honda had a tsb on low/soft pedal
and you have to replace abs unit

 

acrdr: did you do the flush/bleed in the special order for the TL? LF RF RR LR
its odd but true
May apply to many of their models- I only drive a TL

also, after new master or lines off for any reason you must do the 2 ABS active stops from 45 MPH I have described before, that will get out the hidden/trapped air and into the regular system to be bled out

 

All honda/acura have that same procedure for brake bleeding .
I was not aware or the 45 mph abs activation
All my years as a honda/acura tech i never heard of that
I will try that
Thanks

 

got that 2 x 45mph ABS trick from the acura shop manual, as was posted on here some time ago,(possibly gen3 section of azine)
it said required if lines have been opened. After a normal full bleed then test drive, if 2nd time had firmer pedal, there was air trapped in abs= which operation of pump has moved downstream
if so, rebleed all then good to go,
Bubbles were found only in LF on mine but doesn't hurt to push more clean new fluid thru the system as you do the others- that first bubble says you are on the right track!
Once you open brake fluid use it all if you can. Storage with a plastic barrier under cap and its still only good for only 6 months!
brake fluid sucks moisture from the air, wiki hygroscopic for more

the 2 abs stops sure helped after I installed the SS lines and calipers- plenty of opportunity to get air in the system from odd places~ and it did
good helpers are hard to find!!