problem with brakes pedal hard, abs light is on

Transam1170

Registered User
hi, i have a 1990 supercoupe and my brake pedal is hard, the brakes works but the pedal is very hard, which i have to stand on it to stop, what might you think the problem is please help i would really appreciate it thanks
 
Well, it could be a number of things....

Bad ABS pump motor relay
Bad ABS pump motor
Bad ABS pump
Bad ABS pressure switch
Bad ABS accumulator
Bad ignition switch

I would check the relay first as it is the easiest to get to...

It is located on the passenger side fire wall near the hood strut....

Do a search for ABS relay and you will see what it looks like....

You can apply 12v power to it and if it clicks, then it is alright...

Next, check for power to the pump motor....

It's a round cylindrical connector on the drivers side of the master cylinder....

If you have power there, but the motor doesn't run, then your pump motor is locked up....
 
mine was good till about 200 k miles then the brushes went bad in the abs pump , i went to the junkyard and pulled one from an old lincoln that fit

ralph
 
I'm having the same issue sometimes, but my ABS system is different (Teves mk IV? It's a '94 SC). Also, my ABS light is NOT on. It happens probably like 50% of the time or more while braking. Should I be checking the same things? Or is there a clue in there? :confused: Couldn't find any answers for late models upon forum search.

Thanks in advance!
 
Bad Ignition Switch

This was caused by a worn out ignition switch in my 89 Cougar. Turning it back just slightly after starting took care of the issue until a new switch could be installed.
 
Had the same problem last week. Pulled the relay and the power connector, cleanded the contacts, put new electrical grease on the contacts and the problem went away.
 
This was caused by a worn out ignition switch in my 89 Cougar. Turning it back just slightly after starting took care of the issue until a new switch could be installed.

Yep. Me too. 90SC 5sp

Because of me in the process of freaking out due to a very hard brake pedal, I failed to also notice that the turn signals,info display and blower motor had also quit!

Obviously a power distribution problem- I checked all the fuses and relays.
All good.

If I barley turn the key back everything powers up and the pump comes on!

Thanks to all the dedicated SCCoA owners for posting their potential solutions for these problems. :)
 
I'm going to have to give that a go. I still haven't been able to figure mine out, but again, it's a '94 so it could be different. If I am cruising for a while and then have to use the brakes they generally work great but if I brake, let off, then brake again it goes really stiff. Not holding vacuum or something... It only started doing this after I installed an MPx. The car was also sitting for several months before I put it on though.
 
I have read alot of articles on here in the tech forum and it seems like the ignition switch being bad could be a major factor in alot of these issues. Is there a way to test the switch before replacing it to know if thats the problem? The reason I ask is that the 92 SC that I just bought has these problems and I am wandering if they be ignition switch related: Both brake lights on but the car stops fine, no headlights but I have dash and tail lights, fog light switch doesnt come on and the window switches work sometimes and other times they dont. Also noticed the car getting pretty close to over heating when running and sitting still. If any or most of these could be attributed to a bad ignition switch, it would save me a lot of troubleshooting
 
With that many issues, you most likely have more than one particular item that is causing your problems....

I would go ahead and replace the ignition switch....

It is inexpensive, easy to replace, and probably needs to be replaced anyway....
 
I'm going to have to give that a go. I still haven't been able to figure mine out, but again, it's a '94 so it could be different. If I am cruising for a while and then have to use the brakes they generally work great but if I brake, let off, then brake again it goes really stiff. Not holding vacuum or something... It only started doing this after I installed an MPx. The car was also sitting for several months before I put it on though.

check to see if the check valve in the line to your brake booster is still there, facing the right direction (they only flow one way) or if its operational.

also clean your sensor rings....
 
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