I'm :confused: on this one.
Sometimes my brakes feel fine sometimes your not sure your going to stop.
Most times I can't get the line loc to set, it won't even hold the car.
ANY IDEAS???????????


[Modified by mackeyred96, 5:07 PM 3/3/2002]

 

hmm John...can ya be a little more specific bud....is there pressure at the brake pedal...or does it goto the boards?....brakes squeeling?.....

culprits are these......

Master Cylinder
Calipers
Brake Pads/Rotors
Bleeding problems...and association with air in the lines
Power Booster

the more you can help us out....we can help you

jeff :seeya


[Modified by XtremeVette, 4:40 PM 3/3/2002]

 

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What he said, is it a really stiff pedal? Or really soft? Or the pedal feels good, but the car doesn't stop? Just at idle? Or all the time?

 

Maybe the solenoid is going bad for the line loc, happened to me more than once already. I just jiggled the wires and the line loc worked again.

 

Master cylinder? Air in the system? It's probably something simple. Check the little things first. Did it do this before the big mac combo?

 

I do know that the boosters are capible of going out prematurely.

 

I have a similar problem, this is what it does.

When you are driving hard and used the brakes a bit, the brake pedal is hard as a rock, and it doesn`t stop very well at all, sure scares the crap out of ya :eek:

Then, after that, you hit the brakes and they go right to the floor and it hardly stops. Needless to say, I haven<t really driven the car since then, as it happened just before winter and I stored the car, but I will be getting it out in a few weeks.

Anybody have and ideas?

JMR

 

I've changed the line loc solenoid, the brake pedal isn't hard like the booster is going away or there isn't enough vacuum. The pads are almost new. It started this before I did the top end.
It almost feels like I got air in the system but I've bled 3 times and that seems OK.


:confused:

 

Is the line lock before or after the ABS modulator? (Don't know the system).

If I were looking for this I would go for bleeding as well. Now if bleeding offers not improvement it could be that you have some air in the ABS modulator. There may or may not be a bleed fitting on the ABS. However if air is in the ABS modulator you really need a Tech II to work the air out. Using a pressure bleeder would help alot.

Things like sticky calipers and colapsing hoses usually will effect one side more than the other, so this would be a long shot that they are failing evenly.

Master clyinders can leak internally when the seals go, so could never get enough pressure to lock the wheels (or kick in the ABS). But usually it just works badly all the time. Soft pedal that slowly drops is usually master or another leak. Bad master usually won't pump up. When you can pump it up and it works fine that is usually air in the system.

Another long shot is the ABS modulator is stuck in active mode, but again I would think some uneven brakeing would result, but not sure, and this should set a code and an ABS light.

So I would think it's either MC or air (perhaps stuck in the ABS). If the MC ever went dry (like when the LL was installed) you may also have a bubble stuck in the front of the MC, that would act similar - if so jack the back to try and dislodge the bubble and do some foot pumping and bleeding (use hunk of wood to prevent full travel of the pedal - don't go all the way down) to try and work it out.

That's all I can think of for now.

Good Luck,

Pete

 

Thanks for the help.

 

As crazy as this sounds.. I was told certain ABS Systems need to be machine bled. I am having the same problem,Squish pedal, new master, rotors, pads yada. I'll let you know how I make out with mine. I am sure some have heard of this procedure. John G 92 who works at a dealership informed me of this,also my regular mechanic said it's more than likely the solution

 

Try this it may sound stupid but it works. If you don't drive your car everyday and have maybe two or three days that your not going to drive it. Take the cap off of the master cylinder and let it "gravity bleed". Air that is trapped in a liquid eventually moves to the top. Every time I have changed calipers on a car I have did this and it always works.

 

I'll try it, thanks.

 

Who sells 'line loc's" and are they hard to install? I have an auto
tranny...would like to have one!

 

NO, no, no, NO! Sorry, can't let that go. That is not a gravity bleed.

Every flush should end with a gravity bleed, but that's not it; it's just a fine tuning measure!

Gravity bleed should be utilized just like any bleed, except you are using gravity to pull the fluid down. Basically you crack a bleader and let gravity draw the brake fluid out. Using a clear tube into a container of new brake fluid is a good method. It actually does not take too long.

You can leave the cover on the MC, it allows fluid to drop. In fact you should leave the cover on the MC. Hardest part of a gravity bleed is following the bleed order (which is never the same on a C4 due to the ABS modulator location), and waiting. Gravity bleed is a good thing if you pay attention, but will never replace a Tech II and pressure bleed - IF THERE IS AIR in the ABS.

Pete

 

:nono:
leaving the cover off the Master Cylinder will allow moisture to enter the system. Brake fluid is highly hygroscopic. Never expose it to air longer than needed to top off the system.
Maybe a complete fluid change is in order? You should do it yearly as air and moisture can enter thru the seals. :nono:

 

You can buy linelocs at internet racers supply.. :troll

 

yeah on my 1991 vette i am having same problem either will be super hard or super soft and i am not stopping! From what i have heard is to pull the fuse for the abs and then drive it and if it drives fine then you are alittle closer to know what is wrong (ABS)! But if you still have the same problem with fuse out then i would say Tech II time? I have not done this as of yet to much snow on the ground in my town! Try that and let me know if that works or not if the weather is nice in your area. :D

 

Thanks.