Well I'm on the hunt for a Bonne. I found a 93 I like that the owner says has a brake problem. I need to know if this sounds like a trip to Autozone or hundreds of dollars at a brake shop...

What happens is there is a spongy brake pedal, and the brake light is on, not the ABS light though. The car still stops fine, but at a light you can force the pedal to the floor without much problem.

The guy says he put on new calipers and replaced the rubber lines up front cuz they were sticking and the fluid was blackish brown. The fluid looks a bit low, but he says he had it up to the max line and the light came on so he started taking fluid out to see if it went off. It didn't.

I figure the brakes are spongy cuz he didn't bleed them right and that'* a cheap and easy fix, and the light won't go off cuz the sensor in the reservoir has gone bad from having shitty fluid in there for a while. That'* probably not so cheap, but not altogether difficult to fix. Any suggestions or concerns about my conclusions? I am a little pressed for time so prompt responses would be mucho helpful

Cheers

If brake lights are on.. I believe that means it'* there'* something wrong with master cylinder and or the ABS module.

If the pedal slowly sinks to the floor and there are no leaks, it'* probably time for a new master cylinder.

You can get a reman master cylinder at autozone for around $60 but you will probably need to take it too a garage or shop to get them bled properly.

You can bench bleed a new master cylinder without much difficulty. Just follow the instructions that come with the new or remanufactured master cylinder. Most cylinders include plastic fittings and hoses for the job.

Thanks for the replies everyone. I have a few more Q'* though...

everyone seems to jump on the master cylinder bandwagon as soon as brakes come up for discussion.. how often do they go bad on H-bodies? this one was apparently replaced a couple years ago with a remanufactured unit. i wouldn't even have guessed that it had a prob... but you never know with contaminated fluid. also, i was discussing with him how he bled the brakes and get this... he did it with the engine running! hmm... wonder if there'* any air in there... I think a good bleeding will solve the spongy problem.

Also someone correct me if I'm missing something here but the BRAKE light is only tripped by the fluid level sensor and the parking brake? There would be NO reason for that light to come on other than if the fluid were low, the parking brake were set, or the sensor was fouled? I'm just trying to eliminate possibilities here.

Oh one last thing, has anyone paid to get their system pressure-bled? I never have... I just would like to know what to expect if I ask a shop to do it. May be a bargaining point on the price of the car...

Cheers

Once the plug came out, the light went off. I'm thinking it'* a fouled sensor caused by the sludgy fluid - too bad you have to replace the whole reservoir to fix it. Do you think there'* a way to take that puppy off and just clean it out? Right now the car is being driven without the sensor in so as to avoid "dongdongdongdongdongdong....."

You don't have to replace the reservoir. I think it is just pressed into the holes with a couple of "O" rings to seal it. New master cylinders don't come with reservoirs. You swap your old one on to it. It should just lift out.

Hmm. Well, admittedly I have not replaced that many. They don't go bad all that often but the last one I did a few years ago did not come with a reservoir. Obviously they must vary but I'd think it can be removed pretty easily in either case.

I would think you could just spray it down with a can of 'Brake Kleen" to clean it out.

I would not put anything in the reservoir but brake fluid. It will work fine as a cleaner, and will not harm any brake system components.

If the new or reman master cylinder does not come with a reservoir, you WILL want to clean yours out. If your pedal is not going down as you hold your brakes on, and you just have a spongy pedal, then perhaps a good cleaning and bleeding of the system might solve your problem. This can be accomplished with luck for the cost of a couple of big bottles of brake fluid, a turkey baster, and a couple of hours of your time.

You can do a pretty good job cleaning out the reservoir by first sucking out the black gunk with the baster, then refilling with new fluid and using the baster to squirt the junk out of the corners and crevices and repeating until the reservoir looks pretty good. This might solve the sensor problem. But maybe not.

Once the reservoir is filled with new fluid, bleed the brakes to get rid of the spongy pedal and you're done. Bleeding will flush the lines of old fluid too. Reference for bleeding brakes here:

http://bonnevilleclub.com/forum/view...009&highlight=