Homicidal Brakes - need help
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Joined: Nov 2004
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From: Richmond VA
Homicidal Brakes - need help
I am having an issue with my front brakes. The car is pulling to the right under normal driving. On hitting the brakes, the car rips the the left with disturbing authority (even more disturbing when driving HWY 64 in the Ocoee River Gorge). I have read another post about a similar problembut with no answer for me. I have replaced the calipers, rotors and pads with no change in the situation. the Front right wheel doesn't spin freely either. when bleeding the brakes, the left side acted as it should when the bleeded was open - brakes went straight to the floor. On the right side, there was considerable resistance, even with the bleeder open. I checked the hose by disconnecting it at the brake line with the same result - the brakes still had too much pressure even with the hose disconnected. There seems to be a blockage somewhere else. Any suggestions? The problem is bad enough to make the car undrivable.
Safety Car
Joined: Sep 2001
Posts: 4,157
Likes: 554
From: Glenbeulah Wi
Originally Posted by CentralCoaster
I suspect your right front brake line is pinched off, or the hose is plugged or swelled shut.
The hose is swelled shut, I had this same problem on my 1986 vette. Replaced the hose and the problem disappeared.
Le Mans Master
Joined: Mar 2004
Posts: 8,700
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From: Ft. Lauderdale Fl
When jacking up our cars we sometimes jack on a brake line which causes 1. Slow or no bleed. 2. No performance on the brake line side that got bent.
Check your passanger side brake line and follow it from the fuel filter backward, for starters.
Get back to us.
Check your passanger side brake line and follow it from the fuel filter backward, for starters.
Get back to us.
Melting Slicks
Joined: Dec 1999
Posts: 2,816
Likes: 2
From: Austin, TX
Originally Posted by CentralCoaster
I suspect your right front brake line is pinched off, or the hose is plugged or swelled shut.
Since you've already tested pressure with the caliper removed, this is the only explanation I can think of. Either a pinched hard line or swollen rubber line. Relatively quick test, just remove the rubber line where it connects to the hard line and try the same thing again.
Thread Starter
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Joined: Nov 2004
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From: Richmond VA
More info
I checked the line pressure with the hose removed, it still feels suspiciously high "in the pedal." Took far too much force to depress the pedal. I feel this rules out the hose, caliper and bolts/brackets though I will replace the hose just to play it safe. I am going to check the lines tonight, will post what I find. Just curious, but can you actually buy brake lines if one were crushed?
BTW, thanks for all the input.
BTW, thanks for all the input.
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Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Originally Posted by Former Ford Boy
I checked the line pressure with the hose removed, it still feels suspiciously high "in the pedal." Took far too much force to depress the pedal. I feel this rules out the hose, caliper and bolts/brackets though I will replace the hose just to play it safe. I am going to check the lines tonight, will post what I find. Just curious, but can you actually buy brake lines if one were crushed?
BTW, thanks for all the input.
BTW, thanks for all the input.
Melting Slicks
Joined: Dec 1999
Posts: 2,816
Likes: 2
From: Austin, TX
Originally Posted by Former Ford Boy
I Disconnected the hose from the line at the hard point in the wheel well
Next thing to do is follow the hardline all the way back to the ABS controller (behind the driver's seat) and look for kinks / crush. If I remember correctly (I was just under there a week ago) it runs from the passenger side along the cross-member under the engine to the drivers-side, then back along the drivers-side frame rail to the rear-wheel kickup, then over to the compartment behind the driver's seat.
I believe you can buy new hardlines from GM, but replacing them is a royal pain since I'm pretty sure it's one line that runs the entire distance. If you find the damaged area, you may be able to have it fixed with a splice. As long as they use hard-line and proper connectors, it will be fine.
One other possibility is a problem with the ABS controller (since that's where the front brake line gets 'split' into left and right), but I would think that would have set some sort of code or warning light.
Hope you're able to track it down!
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Joined: Nov 2004
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From: Richmond VA
still looking
I replaced the hose, just to be absolutely certain. No change. I looked at the lines and there is no visable damage that I saw. I am beginning to think that it is the ABS pump. Anymore suggestions?
Intermediate
Joined: Mar 2005
Posts: 48
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From: Castle Rock CO
Just a thought, but I was having a pull to the right under hard braking. Turns out that the front shims for the upper a-arm on the passenger side fell out. They were sitting on the frame rail. Put them back in and so far everything seems good.
Melting Slicks
Joined: Dec 1999
Posts: 2,816
Likes: 2
From: Austin, TX
This sure is an interesting one! What year is the car? Some years have a bleed procedure for the ABS pump. When you start the car and put it into reverse, does the pump cycle (sounds like a buzzing sound for a couple seconds)?
Depending on the year, I'm sure someone here with a shop manual can chime in with the ABS pump diagnostic procedures. I have the manual for '96, just not sure what years are the same since they made several ABS changes through the years.
I guess one thing you could do to absolutely rule out a problem with the hard line would be to bleed the system from the ABS controller by removing the front-right line from the ABS controller. Not sure if they're marked since there's 6 lines going in to the stupid thing. Need to make sure you pull the right one!
Depending on the year, I'm sure someone here with a shop manual can chime in with the ABS pump diagnostic procedures. I have the manual for '96, just not sure what years are the same since they made several ABS changes through the years.
I guess one thing you could do to absolutely rule out a problem with the hard line would be to bleed the system from the ABS controller by removing the front-right line from the ABS controller. Not sure if they're marked since there's 6 lines going in to the stupid thing. Need to make sure you pull the right one!
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Joined: Nov 2004
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From: Richmond VA
The car is an 87. The ABS system does cycle properly on initial forward movement. I may have to try bleeding the ABS pump. Hadn't thought of that.
I thought about the suspension, but everything seems to check out there. It's a great thought though. Also, I know the caliper is dragging because of the heat that builds up in it during normal driving. I can also smell the burning pads once I stop, and the wheel is so hot that it burns to the touch (the rotor was actual glowing at one point a couple of weeks ago).
I thought about the suspension, but everything seems to check out there. It's a great thought though. Also, I know the caliper is dragging because of the heat that builds up in it during normal driving. I can also smell the burning pads once I stop, and the wheel is so hot that it burns to the touch (the rotor was actual glowing at one point a couple of weeks ago).
Burning Brakes
Joined: Nov 2005
Posts: 848
Likes: 1
From: 1992 LT1 6 speed Cayman Islands
Pull ECBM codes
I am not sure about the 87 but on my 92 there is a way to pull codes from the EBCM which is the computer that controlls the ABS.
On the 92 it is as follows.
Use a paper clip to bridge pins A and G on the ALDL connection.
Use the TRIP button to cycle down to the 9.0 module on the dash readout.
Press the TRIP ODO button once to move to the 9.1 module.
Press the ENG METRIC button to cycle through the diognostic codes.
write them down.
Press the TRIP ODO button once again to cycle to 9.7 module then press and hold the ENG METRIC button to clear the codes.
If it is possible to pull ECBM codes on the 87, post the codes here and someone can look them up and tell you what they mean.
The ECBM will set codes and not turn on the dash light so there may be a trouble code in there that can help pinpoint the problem.
I don't know if this is of any assistance on the 87 but someone with an 87 can chime in and let us know.
Hope this helps.
Jerris
On the 92 it is as follows.
Use a paper clip to bridge pins A and G on the ALDL connection.
Use the TRIP button to cycle down to the 9.0 module on the dash readout.
Press the TRIP ODO button once to move to the 9.1 module.
Press the ENG METRIC button to cycle through the diognostic codes.
write them down.
Press the TRIP ODO button once again to cycle to 9.7 module then press and hold the ENG METRIC button to clear the codes.
If it is possible to pull ECBM codes on the 87, post the codes here and someone can look them up and tell you what they mean.
The ECBM will set codes and not turn on the dash light so there may be a trouble code in there that can help pinpoint the problem.
I don't know if this is of any assistance on the 87 but someone with an 87 can chime in and let us know.
Hope this helps.
Jerris