PDA

View Full Version : 1995 SC brake questions



skydivr7673
01-26-2006, 04:58 PM
ok, I tried searching but did not find anything that seemed to describe this. My 95 has the ABS light on all the time, and the brake light only comes on for a second, right after I take my foot off the brake. While driving, the pedal feels like there is little pressure until I get about halfway down, then it feels like I have manual brakes--the car does not stop very well and the pedal gets very stiff. The fluid is full, one rear caliper and all rear brake pads are new, and system has been bled. I have no fluid leaks.

Last night I noticed something else--if i drive about 30 mph, and I pump the brakes several times in a row, the pressure builds up and the pedal feels normal, but only until I stop pumping it--if I drive for even just a few seconds and then hit the pedal again, it has no pressure again. I know the 95 does not use the accumulator, so that's out. I am going to pick up a new relay for it tomorrow, but I am looking to see if you guys have any other suggestions. Thanks!

doug93sc
01-26-2006, 05:31 PM
Your on the right track, my old 93 did the same thing and it was the relay that was bad. I replaced it no more light and normal brakes!

skydivr7673
01-26-2006, 05:34 PM
Thanks Doug--replacing it tomorrow and hopefully it will do the trick.

Your pedal was just like that too--with the pressure and all?

Mike8675309
01-26-2006, 06:08 PM
If the relay is stuck on, it may be pulling pressure out of the system through cylcing fluid.

Try the relay. If that's not it, it may be a problem with the vacuum booster section of the brakes. Maybe the master cylinder needs to be rebuilt.

skydivr7673
01-26-2006, 06:44 PM
Is the relay the same as the 89-92 relay, or is it a different one?

doug93sc
01-27-2006, 10:33 AM
I believe it is a different one, on my 93 it was in front of the battery-behind the headlight. It would be best to pull it off first and take it to the parts store for a replacement and yes my pedal was doing the same thing.

skydivr7673
01-27-2006, 01:24 PM
Is it the same relay, doug? The older cars use the GP Sorensen MR120 relay. I went online to check autozone and found that they mention a MR 76 for the 95 brake system, so I am not sure which one to get. Anyone know the part number?

doug93sc
01-27-2006, 01:29 PM
I believe that it is in fact a different relay, get the one specific to your model year, they should have it in stock at a local AutoZone. Like I said pull it off and bring it to the store with you, that is the only way to be sure.

Brad Klein
01-27-2006, 03:12 PM
If you have a code reader you can get ABS codes off the 95

doug93sc
01-27-2006, 04:20 PM
If you have a code reader you can get ABS codes off the 95

I am such a idiot, I completly forgot about the Red ABS plug in......Do a code search first!!!!

skydivr7673
01-27-2006, 04:25 PM
ok--I have a code scanner, but not sure if it will fit this car. I got it to use on my 1994 Ranger 4x4--gonna have to check to see if it is the same.

In either case, I need to know where the relay is and where the red diagnostic plug is for the ABS. Looking around by the battery and headlight, I find a relay(closer to the centerline of the car) with a Ford part number on it. I will write it down and post it up here and hopefully someone can tell me if this is thr proper relay to pull. You guys are a huge help--thanks for the replies and keep it coming!

skydivr7673
01-27-2006, 07:57 PM
ok--I found a diagnostic plug under the hood--it is right on the side of the black power distribution block on the driver's side. There is a plastic cover over it, and the cover says "anti lock test" or something like that. It refers to the anti-lock system. but I hooked into it and scanned it, and it returned a couple of codes that refer to the engine, not the brakes. Or, I should say, the book I have does not have any codes in it for the brake system at all. The codes I pulled are 34, 38, and 78. Does anyone know what this means? I dont have any brake codes--or is there a list of them on here somewhere?

skydivr7673
01-27-2006, 11:42 PM
Another update--

I located the ABS relay that is inside the power distribution box under the hood. It is the same as the horn relay, so I swapped them and tried it out--no dice. The horn works with either relay in its place and the brakes are still the same either way. Tomorrow, I am going to bleed out the brakes all over again, because I think that might actually help. The previous owner of the car has said that the ABS light was on for some time though, but that it did not affect the actual braking as far as he could tell.

I have also heard that there is an ABS relay on the passenger fender next to the EEC-IV test plug, but there is nothing there on my 95. Any other suggestions would really be appreciated!

skydivr7673
01-28-2006, 05:42 PM
anyone? any other ideas?

Kevin Varnes
01-28-2006, 05:48 PM
You need to find out what those codes are. Otherwise you'll just be guessing at the problem. A quick google search turned up nothing. What manual are you using? I've got a Ford Service manual, but it is for an '89 and the codes could have changed. Perhaps someone here with a newer brake system Ford manual could look them up?

skydivr7673
01-28-2006, 06:23 PM
I found the codes but they dont tell me anything. They all relate to the left rear wheel ABS sensor, but that would not cause the entire power brake system to stop working. It would cause the ABS to function wierd perhaps but I dont even have regular power assist.

if I pump the brakes several times while the car is moving, the pedal gets increasingly harder, and it becomes very stiff to push down at all, but there is noticeable brake pressure and the car will stop much better, but as soon as I stop pumping the brakes, that pressure goes away and it's back to manual braking

Brad Klein
01-28-2006, 09:06 PM
You can check the relay by checking the resistance between pin 85 and 86 it should be between 45 and 90 ohms

from the manual:
Spongy brake pedal with/without anti-lock function (no warning indicator)(cause the bad sensor is tripping the light)

Check for proper brake pedal and booster/master cylinder attachment
Bleed brake system

There is a way of checking the whole systems wiring but it says you need a rotunda breakout box part #014-00322 this would let you know if everything is getting power

Have you done any brake work recently? Have you checked the bleeder screws maybe one cam loose?

Hope this helps I have my manual sitting here so just ask if it doesnt

skydivr7673
01-28-2006, 10:39 PM
Thanks Brad....

Ok, so far here is what I have.

1--Rear brake pads are new. Both sides were bled and fluid was topped off. No leaks.

2--ABS light is on all the time(was before I did the brakes too).

3--Brake light only comes on for a second, and only right after each time I take my foot off the brake. Brake light functions normally at all times otherwise.

4--Pedal feels like there isnt much attached to it until I get it most of the way down, then it feels hard, and braking is slow, just like it is manual only. However, when driving, if I pump the pedal halfway a bunch of times, it seems to build pressure, until stopping is more like it should be, but the pedal is fairly hard all the way down. This only works until I release the pedal, then pressure is lost again right away.

I finally found the relay inside the Power distribution box. It is identical to the horn relay next to it, so I swapped them and tried it out. The horn works fine with either relay and the brakes have no change with either relay. So either the relay is good, or it is used differently by the horn.

I just checked it tonight and fluid is still full, so the screws must be tight, because the pressure would have bled it dry while driving otherwise. There has been no change in the system this whole time, so the problem is not from something that just was done.

I think I about covered everything there. I was told that there is a relay next to the EEC check plug on the passenger fender, but there is nothing there on mine--I only found the one relay. Is there a second relay somewhere that might be blown? I cna check the resistance on this one just to make sure, but I am beginning to think that it is not the relay. Any thoughts?

Brad Klein
01-29-2006, 10:59 AM
Well the ABS light is on because of the sensors

Here are some diagnosis from the book

pedal goes down fast = Air in system or a bad master cylinder
pedal eases down slow = same thing
pedal is spongy = brake shoe and lining or hydraulic system
slow or incomplete pedal return = brake booster or master cylinder

To check the master cylinder jack up car apply brake pressure after 15 sec with brakes still on try turning a front wheel

Brake booster check with engine off and all vacuum in systen exhausted press pedal down and hold start the car if the pedal goes down everything is fine if not the system is not working

skydivr7673
01-29-2006, 11:06 AM
Brad--

for the master cylinder check, does the car need to be running? Also, thanks for the great info! Gonna check these out this morning ang I will let youknow how it turns out.

And if the front wheel turns, does that mean the m/c is bad?

Brad Klein
01-29-2006, 12:56 PM
I doesnt say I would try it both ways

yes if the wheel turns its bad