IndyBlackTL

Ok so here is my problem. My right rear rotor was dragging and sometimes would cause the pads to smoke. I assumed it was probably the caliper and that it was locked up so I decided to replace both rear calipers, rear rotors (both sides had signs of heat damage), pads and e-brake shoes (thought this could also be a possibility seeing as how my e-brake didnt work well). So everything gets replaced and back together and after we bleed the brakes the rear wheels are almost impossible to spin by hand. Soo same problem but the left is doing it as well and its 10x worse because everything is nice and new and not worn. I am leaning towards a few ideas. Either the master cylinder has gone bad and the rear side wont let the caliper piston return or the VSA rear side has gone bad and wont let the caliper piston return. Anyone had this problem?? Any ideas?? Gonna do some more tests this week on it.

BradE

I think you're on the right track, also make sure the mounting brackets aren't bent, causing the contact. I would be pretty odd they are both bent, but it's another thing to check.

johnny3

Check up at the brake pedal, there should be a little clearance between the Mst. Cyl. push rod & brake pedal linkage.
You may have to correct that & bleed again.

IndyBlackTL

Thanks guys. Should have it on the lift sometime this week. Sucks not having my car.

IndyBlackTL

After looking at it on the lift and trying a few different tests it either has to be the VSA or the proportioning valve. Idk what else it could be. It's very very odd. I find it very hard to believe I am the only one having this problem if it is the VSA modulator.

nfnsquared

Can you actually see/tell that the calipers have the pads clamped against the rotor?

Are you sure it's not the parking brake shoes not properly adjusted? Did you perform the parking-brake major/minor adjustment procedures in the service manual?

Turbonut

iTrader: (1)

Flexible brake lines can have an internal break and not allow the fluid to return, so the piston stays out, but as you are having a problem with both, I doubt this is the culprit. With the wheels locked up, hard to turn, loosen the bleeder and see if that makes the wheel any easier to turn. When you did the rear brakes you didn't use visegrips on the rubber hose did you?

IndyBlackTL

Yea its def the caliper not the parking brake. We pushed the piston back in and spun the wheel then bled the brakes and once you apply pressure the they lock. Basically its like the fluid can flow to the caliper but nothing comes back when you let off the brakes. Very odd. Im with you on the hoses.. being that its both rears its kinda odd. You can open the bleeder, disconnect the lines at the caliper, VSA, and master cylinder and still CANT spin the wheel. HOWEVER you can take the caliper off and push in the piston like normal (we used a clamp so its hard to gauge how much force it took but it didnt look hard to move at all). Very odd situation. I ordered a new proportioning valve and rear hoses. Gonna start there. If that doesnt do it then its on to the VSA.

01tl4tl

wasnt there a TSB on the modulator- something about it put air into the ABS resulting in soft pedal
May have been other symptoms or similar problem--ck TSB master list

did you bleed them in the correct order?- acura special for the TL:
driver front then clockwise around the car= LF RF RR LR

what did the old brake fluid look like? black?

IndyBlackTL

Yes there is a TSB on the VSA. But those symptoms didnt fit. So we fixed it today. The problem was that there are 3 rivet looking things on the back of the pad. The top one was getting caught in the caliper piston causing it to tweak enough to bind the slide pins from returning to the open position. Pretty weird. Ground down the rivet and everything is fine. So no problems with that anymore. Only problem I am having now is that it feels like the brakes need to be bled even though they've been bled 3 times. That could be where that TSB comes in at. lol. This is by far the weirdest shit I've ran into with a car.

Shitty pics but here you can see the rivet and prolly cant tell but half of it is smashed from the caliper piston.


and here is the piston. Tried to circle it so you could see but its got a big spot in it from that rivet contact. Crazy stuff.

johnny3

Thanks for telling us the final fix on this.

IndyBlackTL

No problem. I should also throw in that they were Hawk ceramic pads and NAPA reman calipers. Idk which one is the culprit.. if I had to guess I would say the calipers cuz I doubt I am the only one on here using Hawk ceramics.

nfnsquared

Hmmm...Very good find! That's a weird one. I know a lot of folks have Hawk ceramics on the front but don't recall for sure if anyone has put them on the rear.

Also, I seem to remember 01tl4tl talking about a certain brand pad that needed a tab or something removed before installation, but I think this was on the front.

nfnsquared

Yep, 01tl4tl was all over this 8 months ago. Middle tab is bad joojoo:

https://acurazine.com/forums/showpos...3&postcount=32


"NOTE: It has been found that several pad makers are/were using the wrong backing plate for the rear pads. It has 3 raised tabs on the back of the inner pad
Should only be 2, one on each end (one secures the squeeler tab the other is not used)
If there is a 3rd tab in the top center of the pad- it will contact the caliper piston and cause the pad to go in crooked against the rotor when brakes applied!!!
Applies to gen2 and 3

Easy check is look under the car at rear rotors- if half the width is rusty and other half shiny- guess what!
Can be fixed by grinding off the offending center tab- flush

Check all new pads for this problem before install (if not OE pads), and check the rotors on any rear brake job done in the past for that rust/shine situation

Real Techs: please check this when you see a TL or CL...a peek at the inner side of rear rotor takes seconds and can save lives
hawk rb and several others all used the same backing plate part number- companies I found were notified and some have made the change/correction

That pad back is actually for an RL which has a different park brake system and needs the 3rd tab to operate it---
Im guessing that somewhere along the line some years ago at a brake company:
an assistant looked up a part number for acura pad plates- put it in the computer system and the next place looked up info from them,,,it went on and on with incorrect info
GIGO!! garbage in garbage out- computer only as good as its programmer"

IndyBlackTL

Well I'll be damned. lol. That coulda saved me some time. I'm still lost on why all the sudden I cant get any brake pedal in this thing all the sudden. You would think after 3 bleeds it would be fine.

nfnsquared

If any air got into the VSA unit, it may take a while to get it out, if it will even come out at all. Don't know what to tell you. I could only recommend bleeding the entire system once again with enough fresh fluid to absolutely ensure you've flushed the entire system.

Next option could be to see if Acura will replace the VSA unit...

01tl4tl

as I was reading thru this thread again and saw the tab pic...ahh memories
The weak braking.. with only half the pad making contact as the tab cocked the pad when applied as piston hit tab-

Everyone:
look at inner side of rear rotors for half rust/ half wear across the face, if you replaced your rear brake pads with anything but honda pads

It was major pita trying to figure that one out!

I recently threw hawks on my 01 to compare to the RB ET300s Ive been running-and had run down to minimums,,
had to grind that extra tab off hawk rears before use- repaint the backing black etc

its not the caliper... its hawk

while parts should fit--- you always have to double check yourself- visual- measure whatever you think it needs

those pad backs are for the rsx rears- the tab is for their park brake system
Once 3rd tab removed you can use them on a TL

rebleed the system -driver front then clockwise around the car lf rf rr lr
Do 2 ABS active -its pumping the pedal under your foot as you stand on the brakes at 45mph to full stop
repeat and if 2nd time had firmer pedal there was air in the abs controller
rebleed system and should be ok

If prob after that- abs modulator prob/ VSA- see dealer for TSB/(secret warranty)

01tl4tl

when trying to bleed system with partial pad contact- the piston in the caliper gets crooked and doesnt make correct pressure

do it again and the results should be much better

REMEMBER
Never let the brake pedal go to the floor with bleeding!!!
That hurts the master cycl seal
If noob helper.. place a 2x4 wood block under brake pedal -limit its travel to 3/4 to floor like it experiences in normal use

IndyBlackTL

Lots of good info there 01tl4tl. Yea that tab was a real pita. To think I almost ordered a new VSA lol. I woulda been pissed! So I re-bled the brakes today and they are much better. Gonna keep getting the ABS to activate and bleed until everything is good. Thanks for all the help on here guys.

01tl4tl

once you have done the 2 ABS active stops to see if there was air in there- and you removed it from calipers if it was discovered--
You are cleared to drive normal now-
no need for repeated abs stops unless you think there is still a prob you are testing for