[doug4]

Hi, hope someone may be able to shed light on this... Bought '93 T Conv last fall, and noticed that the brake pedal effort is really high compared to my other cars...Thought it could be vacuum leak/brake booster problem, but searching the archives I found that w/ABS, there is NO vacuum booster...

The only other symptom is that the Antilock and Brake fluid lights stay on for about 20 seconds after the car has started, but then go away and remain off...

Should I look at the ABS ECU? Does anyone know how to read the codes, or do I need to see a dealer/specialist?

Appreciate any feedback!

Doug

 

[Fakie]

The ABS gives a very different feel to normal 900 brakes. I have got it and it took a while to get used to. They are not as progressive as Non ABS and feel stiffer. It took me about 6 weeks to get really used to it.

The reason the lights stay on for so long is that the ABS needs to build up a vaccum. If you listen you can hear it pumping. Although saying that 20 seconds is a fair amount of time. Normally if you havent driven it for a while then it takes longer.

The ABS check light will come on if there is a fault with the unit and the fact that it is going out should mean there isnt.

 

[cdaly]

<pedantic mode on>
The ABS system doesn't use vacuum at all. What it is building up is pressure in the metal ball-shaped brake accumulator which you'll see beside the fluid reservoir.
<pedantic mode off>

It then uses this pressure to activate the rear brakes and to assist the front brakes.

You can test if the ABS system is working pretty easily:

1. Find an empty road on a wet day.
2. Get up sufficient speed, 40 mph should be enough.
3. Check that there is no other traffic in sight, neither in front of you in case you skid into their path nor behind you so that they don't have to stop suddenly.
4. Check again.
5. If the road is clear, stand on brakes and clutch with full force.

If the ABS is working, you'll feel the 'chatter' through the brake pedal, if it's not working, you'll skid.

Incidentally, the ABS system is very handy for checking road surface conditions. If you press the brakes a bit suddenly and the ABS activates, the surface is low grip enough that you should drive with due caution...

 

[Fakie]

Thats me told

 

[doug4]

Strange Brake Problem

Thanks for the info! I'll take a look at the accumulator to see if I can verify that's it's working correctly. Brakes well enough initially, but when I'm trying to come to a complete stop at an intersection, then I notice that I really have to lean into the pedal...Or it may just be typical of this system...

Doug

 

[DanComden]

Swapping between my non-ABS '85 and my ABS '90 still gets me a little stymied. It's obvious the brake systems are different -- the '90 has a much harder pedal.

That said, if you have to exert a lot of pressure on an ABS system, something isn't working quite right. I don't know how much work you do on the car on your own, but consider flushing the brake fluid and see if that helps...

-*- Dan

 

[DrSquirley]

The abs brake feel is alot harder, this is true witht he 9000 abs system as well, and doesnt really denote a problem. Now if your pedal starts to get a little sloppier and gives easier, i would then have it looked into.

-Alex

 

[Fakie]

Another way to check your ABS accumlator is working is to turn the car on but not start it.
Wait till the ABS lights go out.
Then pump the brake pedal 20 - 25 times.
The light should come on because you have used all the pressure up.
Then see how long before it refills it.