Brake Warning light (on dash) inoperative / rear drum brake adjustment

[DrWho]

issue #1

The Brake warning light on the dash of my 95 monte carlo does not come on , it never has since I got the car a few months ago , the ABS light also never comes on .. now I undersatand both lights should come on when you first turn the key (bulb check) and they do not , also brake light should come on when parking brake is used, it does not ..

 

ABS VI does not work , I have tested it by stoping the car fast on slipery road, I suspect its been disabled (which is fine with me) , but I still would like the regular brake warning light to work ..

 

well first thing is to check the bulb right ...I have checked the service manual , and its not very specific about how to remove the Insturment panel , shows a diagram from a grand prix which does not look same as what I have .. I got the screws removed , but I cant seem to get the panel out , maybe getting stuck on the wireing harness hard to say , I cant get at it very well , does anyone know a trick to removing the monte carlo/lumina insturment panel ? or any other suggestions ??

 

A buddy tells me that the ABS was probably disabled by computer which makes sense , these bulbs cant be disabled by computer can they ???

 

 

issue # 2

the back drum brakes dont seem to work all that great , they were out of adjustment and so I adjusted them and lubricated the adjuster .. and they worked better after that , the car felt like it was braking more evenly front to back , but now after a few days driving its back to feeling the same as before (with front brakes doing most of the work) .. maybe its still not autoadjusting properly ?? shoes are pretty new 75% remaining ..

 

maybe I should bleed the rear brakes , thinking thats a good start anyhow with minimal investment... but I have a feeling that adjuster maybe sticking ,,,

 

but I bet that IF my dashbord brake warning light was working , it would be lit because of these issues /// hence why I would like to fix it ...

 

any ideas on these issues are greatly appreciated .. #1 priority is how to fix the brake warning light ..

[gp90se]

I have no clue with the ABS issue, i hate abs anyways, so IMO, your better off without it.

 

The adjusters on the few w-body cars that got drums suck. when you say you lubed them, that did you use? I would suggest pulling the adjuster out, clean the threads with a wire brush, anti-seize it and reinstall. check for burrs or anything that could be preventing the adjuster from moving easily. are the springs warn out on the drums as that could be causing you issues as well.

 

wait, did disk/drum cars get abs?

 

BTW, when do you think that brake light should come on? put the ebrake on and see if it works. it should only be on when the system is low, no pressure or the ebrake is on.

[DrWho]

 

Thanks for the advice about the drum brakes , I remember it did not move as freely as I thought it should even after lube, I did use anti-seize but I should probably have cleaned it more thoroughly (I did not have much so I may not have used enough) , the springs seem ok , but I do have a spare set that only cost 18 bucks , so I may just install them.. when I backup and slam on the brakes fast it seems to adjust it , but I think that it should not require that much force..

 

one other note , the shoe on the rear side (gm calls this the secondary shoe) seems to be wearing less than the one on the front (gm calls primary) and specifically near the bottom of that secondary shoe its hardly worn at all , perhaps that could be a clue , or maybe its normal ..

 

it does have ABS , I am 100% sure its disabled , and it can stay that way.. my main concern is that warning light , its does not come on at all , ever , not when you first start the car or when you have the parking brake on .. maybe its just the bulb but hard to say as I'm having trouble getting at it .. I'd like to get it working as its there for a reason , like to tell me if fluid is low etc..

-anyone know how to get the insturment panel off on a 95 monte carlo ?

 

Ideally I'd like to take out all the ABS crapola and replace it with a standard master cylinder, I just dont trust that whole ABS VI setup , I suspect it maybe contributing to uneven braking.. but who knows , think I will take the drums off again and see if I can get that adjuster to move more smothly first.

[1990lumina]

From your use of primary and secondary shoes I'm assuming you have duo-servo type drum brakes on your car?

 

Both shoes SHOULD be wearing close to equally. However, if you in fact had a leading/trailing type drum brakes the leading shoe would wear out and the trailing way barely be worn.(easy to tell because the anchor for the shoes is at the bottom and the two shoes are NOT connected in any way on leading/trailing, while duo-servo has the one anchor at the top and the whole assembly is free to move)

 

You should lube the adjuster with a good amount of silicone grease (we use some shit in a green tube..Dow Corning 111)..make sure the backing plate is greased up well on the shoe contact points (again, silicone ONLY).

 

With the duo-servo type drums the lprimary shoe is pushed against the drum by the wheel cylinder, and that force "self energiezes" the lprimary shoe to pull itself into the drum, and by doing that is pushes the secondary shoe against the drum. This provides better braking over leading/trailing but the whole assembly takes too long to free (duo-servo isn't as efficent to use with ABS systems).

 

I'm gonna venture a guess that either you adjuster isn't working right, or your drum is over sized and the shoes aren't contacting properly internally. Also, make sure your preliminary adjustment of the shoes is good, because it will take quite a few reverses for the auto adjuster to do it's thing (if it was in fact working correctly).

 

Lol, sorry about the long post..I'm taking brakes in school right now and we just finished the week on drum brakes last week..so I could write a novel on those fucking things. (By the way I hate them, disc brakes FTW) lol

[ManicMechanic]

You know...One of the designers for Delco Moraine back in the 60s HATED disc brakes...

 

He was the one that came up with the parking brake in the rotor...

[1990lumina]

You know...One of the designers for Delco Moraine back in the 60s HATED disc brakes...

 

He was the one that came up with the parking brake in the rotor...

 

My Millenia has the parking brake in the rear rotors. IMO it keeps the rear calipers simplier with less things to go wrong, and less expensive to replace if/when they do need replacement.

[ManicMechanic]

Precisely his point...As I said, he hated disc brakes, so he incorporated the mini drum set up just to piss off GM...

[1990lumina]

Lol!!

[DrWho]

Thank you 1991lumina for the great info , I have a feeling the problem may be partly caused by "the drum being oversize" I do have new drums and though I have not installed them yet , I did just test to see how they would fit on one side and I had to crank the adjuster down quite a bit to allow it to go on , so that means the new drums are a bit smaller inside than what I have on there now ,, guessing existing onese are just old and worn and/or have been machined a few times..

 

I'm pretty sure they are leading/trailing type , I wish I had a picture to attach , but I can explain what it looks like , there is one spring that hooks to a slim metal thing that hooks to the adjuster , and then the shoes themselves are hooked to a large solid U shaped spring that goes down around the bottom..

 

I'd rather not replace the drums if I dont really have to as they are the most costly , but maybe its best to do everything , drums & shoes all at once , rather than put new drums with worn shoes or new shoes with possible out of spec drums ..

 

I have not had time to take it all apart again to lubricate the adjuster yet , maybe I'll just make sure its all moving well first and see how it is , the shoe appears to have at least 60-75% left on it , so hopefully I dont need to put new shoes or drums on and just lubricating it better will do it...

 

when I do take it apart I will try to take some pics of what it actually looks like

 

--- anyone know how to take the dash apart to so I can get at that bulb ? ( I got the front cover plate off , and 2 screws out of the instrument panel , but cant figure out how to get it to come out w/o possibly damaging it.

[IRONDOG442]

Intrigues have the mini drum inside the disc too, Intrigue FTW !!! AGAIN !!!

[1990lumina]

On the drum itself it should have the "disacard limit" stamped onto it. Measure the diameter of the drum and make sure it isn't any larger then the max diameter stamped. I know it's probably stamped in metric, which suck when trying to measure it with precision.

[DrWho]

have not had a chance to take em apart yet , but I will measure the inside of the drums when I do.

 

I managed to find a page with pictures of the type of rear brakes I have:

http://www.autozone.com/az/cds/en_us/0900823d/80/1b/f0/d9/0900823d801bf0d9/repairInfoPages.htm

 

funny thing today it seemed better , like it had adjusted itself correctly finally , still I think its sticking at times so I still intend to take it all apart clean and lube the parts properly .. I got some stuff called AGS Sil-Glyde Brake Lubricant , which I intend to use.

 

 

[1990lumina]

If you are going by the picture on the autozone site your car has leading/trailing drum brakes. The wear you mentioned is typical (leading shoe is worn out and the trailing is near new). This type works better for ABS because it releases faster. The adjuster works similar.