'97 with clicking and brake problems

[sandyshores]

Hello all,
can anyone offer any help as to the exact nature of this problem? Ive searched the archives and found at least 3 or 4 people with this same problem so I know that it is common. The problem is that no one answered their posts so I'll have to wait and see what happens. Also, with the high number of ABS posts I think it safe to say that these models definitely have ABS issues!

My problem is that I hear this clicking noise from what appears to be the master cylinder/ABS pump and have weakened brakes while on the road. My mechanic has replaced the ABS pump and EBCM but the problem still remains. He claims that their were no codes in it but I dont think he has the correct "reader" tool. Any help on this matter is greatly appreciated.

[sobek]

Hi,

I think I'm starting to have very similar problem.
Every once in a while (more often recently) when i start the engine the Antilock light comes on about 2 sec after all controls turn off. Sometimes it happens together with red brake light on. I noticed that when Antilock light is on, when increasing engine rpm, a fast clicking or whirling noise can be heard (from "behind the radio" ), and its pitch is in relevance to rpm. I could only hear it from the inside of the car, you couldn't really notice it with the hood up. This does not happen when there is no brake code lit on the dash.
Would it be connected wih another issue i had in this car since I bought it over a year ago? - When started, brake pedal pops by 1-2 inches up and down with a clicking sound to it - it feels quite loose for a few seconds, and then everything comes back to normal.
Would this mean a booster problem? I also noticed that when car is parked, but running and i press brake pedal quickly several times - headlights dim and engine starts runing rough.
Apart from that, car runs really great!

Any Ideas? Thanks for help.

Sobek - 97 Monte Carlo LS, 3.1L, 137K

[richtazz]

There is a vacuum check valve in the booster that may be going bad, causing the lights dimming, hesitation and sinking pedal. The brake warning light coming on is either low brake fluid, a bad fluid level sensor in the master cylinder or a pressure problem. Since it sounds as if the ABS motor is kicking in, I would suspect a bad master cylinder.

[sandyshores]

Hey, its nice to see some continuation with this thread. I really hope that maybe some definitive info will be found so that other users may benefit. Sobek, Im sorry to hear that you're having the same problem. All of the other posts Ive found have also been with '97s...mostly. As far as my car, I never got to the bottom of it. My mechanic was terrible and hit me for such a huge bill that I just abandoned it. I had wrote to Bendix as they have an "ask the answerman" at their website. A qualified techincian responded in a timely fashion and was certain that it was an ABS sensor issue. I tried to tell my mechanic but he would'nt go for it. Because I also had the dimming lights he went on to chase down an alternator issue to no avail. Bendix said to just clean the sensors real good as apparently this is quite common. Also to inspect the wiring as well. The only problem is in getting to the sensors as they are quite hard to get to.

Richtazz, good input as well concerning the vacuum check valve in the booster. Probably the only thing my mechanic and I never addressed. We actually replaced the master cylinder and ABS pump that is attached to it with no luck. Sobek, please keep us posted as to what you come up with. I never did get any replies to other posts I put up on other forums. Just a big mystery tht I'd love to get to the bottom of.

[maxwedge]

It seems if he scanned it with an abs function scanner and checked wheel speed sensor inputs the problem would have been found. I had the same thing on my 98 LTZ, scanner actually had a fault related to the ebcm but at the same time a ft sensor showed no input below 10 mph, replaced speed sensor, that fixed the problem of abs activation when driving at slow speeds and corrected the ebcm code. Some scanners can throw you off track with abs codes, got to observe live operating data.

[sobek]

Ok, whats the rule #1 ???
Go with the simplest solutions!!! It helped me fix my problem!! And it's such a relief!

To follow up my previous messege, I need to add that I've noticed a weird thing happening to my car whenever (and only then) when anit-lock and/or brake light was on - when opening windows I could hear a high pitch sound coming from window motors.
So I contacted my previous mechanic (I'm polish, he lives in Poland I currently in the US, but hey, cars work the same here and there), told him what's going on and he advised me: You don't have ground.
So I checked all the cables I could come up with (by hand, with limited tools, - I'm not a mechanic) and everything seemed fine.
So the other day I go to my car, try to crank it and - nothing, no power whatsoever.
What was wrong? Hahahaha, battery cables!! Both + and - were loose!
Everyone who has this MC model knows how hard it is to get to the battery. In my case even when I was checking "by hand" if the cables aren't loose it seemed fine, and the cables were not corroded - so I just didn't pay much attention to it.
After tightening screws EVERYTHING came back to normal, car drives flawless, and my mechenic was right!!

Sandyshores, check (maybe change) your battery, the battery cables, ground and such - todays car are very sensitive to any "juice" related issues!

Let me know if that helps!
Sobek

PS. And, boy, I'm quite happy I didn't fry any electronic parts in my car....