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Old 02-07-2008, 06:52 AM   #1
kansas girl
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Intermittent brake problem on '95 Saturn SL2

Hi everybody. I drive a '95 Saturn SL2 with ABS and traction control. It has about 78,000 miles on it. It seems to be having a brake problem.

Before I start, let me explain that I have neither the skills nor the facilities to work on a brake problem myself, and I will be taking it to a shop. But I haven't lived here long enough to have found a reliable place that I trust, so I would rather go in with some idea of what is wrong, so that I'll have a better chance of recognizing if someone gives me complete BS. Also, my problem seems to be intermittent, so we all know that it will NOT do it at the shop, right? And then, if they can't tell what the problem really is because it's not doing it, they're even more likely to start suggesting I replace random parts that probably don't need replacing. So I like to go in armed with as much information as possible. And I'm just as happy to hear what it probably isn't as what it probably is -- again, so I'll recognize BS.

This problem doesn't happen all the time. The first time was on Monday morning, only a couple of minutes after I first started the car. I was stopping from maybe 10 mph and it felt like I was pressing on the pedal but almost nothing was happening. The pedal was not squishy or going to the floor; if anything it was harder than normal. But as I drove around (slowly and carefully!) it seemed to get better. I wondered if maybe the brakes could have been very wet. It was extremely foggy that morning and absolutely everything outside was dripping wet from it.

It seemed ok the rest of that day and yesterday. Maybe not quite normal, but it's so hard to tell if there's really something going on or I'm just imagining it. Certainly nothing like the initial incident.

It snowed last night and I went out in it today. I tested in an empty parking lot to make sure things seemed ok, including the ABS and traction control. Then on the way home I had to stop a little faster than usual, and again I had that scary sense you get when you're trying to stop but it isn't happening. The road was slick, and the ABS seemed to be activated as I would expect (it's quite noisy in this car, you can't miss it). It still didn't feel right though. It's hard to be sure, because it was slick, and ABS is not magic, so you can still need a longer stopping distance even when everything is working. But again I think maybe the pedal felt harder under my foot. If I'm not imagining it.

I barely avoided running into the car stopped ahead of me, and then I went the rest of the way home, and as far as I could tell the brakes were back to behaving normally the rest of the way.

There are no unusual indicator lights when I start it or just while it's running. The traction control light flickers on and off as the traction control is activated, which is normal. I don't think I've ever noticed if there's a light when ABS is activated. During the times the problem happened, I was not looking at the dashboard, obviously, so I can't say if there is anything lighting up then.

The research I've done so far suggests this could be a problem with the power brake system. But I haven't seen any suggestion that it could be intermittent. One site suggested the following test: with the car off, pump the brake pedal a few times until it gets stiffer. Then hold down the pedal and start the car. I tried this, and as soon as the engine started, the pedal got softer. If I read it right, this means the power booster is working (at least at that moment). But this could be completely the wrong track anyway.

I will be very grateful for any suggestions anyone has as to what is going on. Let me know if I've left out some important piece of information.

Last edited by kansas girl : 02-07-2008 at 06:56 AM.
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Old 02-07-2008, 07:30 AM   #2
newyorker
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Might be an air bubble in the brake lines...not safe at all, but im not sure if thats the problem, its the best I can deduce from what I know
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Old 02-07-2008, 05:13 PM   #3
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Quote:
Originally Posted by newyorker
Might be an air bubble in the brake lines...not safe at all, but im not sure if thats the problem, its the best I can deduce from what I know
wouldn't an air bubble make it softer? harder that usual sounds like a loss of the power brakes, like she suggested. and if the pedal got softer when she started it, the booster was working at the moment. I am not sure where the power brakes get their power from on that car, but that could be the source of the problem.
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Old 02-07-2008, 09:31 PM   #4
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Quote:
Originally Posted by dvdrose18
I am not sure where the power brakes get their power from on that car, but that could be the source of the problem.

I think you're referring to whether it is integral ABS or not? As far as I could tell from stuff I found on the web, my car probably has a Delco VI ABS which is non-integral, so there would be a vacuum based power booster separate from the ABS. (Which fits, since it seemed like the problem was happening at the same time as the ABS was doing its thing more or less normally.) I have been trying to imagine what would create an intermittent problem in a vacuum system, but I just don't know enough about it.

Thanks for the suggestions so far!
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Old 02-07-2008, 10:01 PM   #5
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Quote:
Originally Posted by dvdrose18
wouldn't an air bubble make it softer? harder that usual sounds like a loss of the power brakes, like she suggested. and if the pedal got softer when she started it, the booster was working at the moment. I am not sure where the power brakes get their power from on that car, but that could be the source of the problem.
When I had air in my clutch lines, my pedal was kinda sticking, that why I said im not really sure about if its a bubble or not I dont know what other effects they have.

Regardless, if we cant give you an answer, get it looked at, the sooner the better, its a pretty big safety issue.
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Old 02-08-2008, 03:34 AM   #6
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If you didn't have it serviced it's hard to imagine there would be air in the lines. The lines are under extreme pressure and in order for air to get into the system, fluid would be leaking all over. Your booster has a vacuum hose connected to it.

When the abs activates it does make the pedal impossible to push, and will even push against you, could this be what you are feeling? It could be that your brakes are fine and maybe your tires are getting worn out, maybe you just didn't notice it until this year.

The rear calipers on those cars (if yours has them which I think it does) are prone to getting stuck over time, maybe they aren't functioning properly and the pistons are stuck. Does your emergency brake work (The e brake works by moving the actual piston so if the piston is stuck the e-brake won't work very well)? You could jack it up and make sure all the wheels turn freely in neutral and maybe get a friend to see if they stop when the brake is pressed. If everything seems to be working right it probably is, (disclaimer: but for safety sake you should have it checked out regardless.)
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Old 02-08-2008, 07:56 AM   #7
kansas girl
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Quote:
Originally Posted by carls47807
When the abs activates it does make the pedal impossible to push, and will even push against you, could this be what you are feeling?

I don't think that's it. I do little tests pretty often to see if the area I'm driving is slick enough for ABS to activate, and of course to see that it actually is working. And it's winter. :) So I am pretty familiar with how the ABS feels. Also, the first time it happened, it wasn't slick so the ABS, of course, didn't activate. Then again, maybe I just noticed more the second time because I was worrying about it.

Quote:
Originally Posted by carls47807
The rear calipers on those cars (if yours has them which I think it does) are prone to getting stuck over time, maybe they aren't functioning properly and the pistons are stuck. Does your emergency brake work (The e brake works by moving the actual piston so if the piston is stuck the e-brake won't work very well)?

Rear calipers = it has rear disc brakes? Because the equivalent mechanism is called something else on drum brakes...is that right? It has 4 wheel disc brakes.

I took it in today and the guy didn't have time to do a full inspection (i.e. wheels off) but he put it up on the rack and looked at it, and showed me. He didn't see anything wrong except that the rear pads are getting low and the rear rotors might need replacing too. And of course the brakes behaved perfectly the entire trip and while it was there.

As for the emergency brake, it feels normal when I set and release it, but I haven't actually tried to drive against it. I always set it when I park, even though the car is an automatic and people tend to look at me funny. I'll try it tomorrow.

Thanks, and that is a slick looking paint job on your Corvair!
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