Brake problem... - Second Generation Forum

Forum Post / Reply
You must log in before you can post or reply to messages.
Brake problem...
Sunday, July 24, 2005 5:31 PM
ok about 2 weeks ago i noticed my brake pedal would keep going further and further when stopping, since then ive replaced the master cylinder, brake booster, and both wheel cylinders in the rear, bled all the lines and the pedal goes straight to the floor EVERYTIME, no visibal fluid leaks, brakes are nearly new. Any ideas?




Re: Brake problem...
Sunday, July 24, 2005 6:10 PM
bad master cylinder



Re: Brake problem...
Sunday, July 24, 2005 6:16 PM
pezed wrote:bad master cylinder


ive had 3 different masters in thise car including 3 different boosters, the alst master/booster was a rebuilt combo.



Re: Brake problem...
Sunday, July 24, 2005 6:51 PM
The only way the pedal can go to the floor is a leak, either in a line , caliper/cylinder or in the master cylinder itself.



Re: Brake problem...
Sunday, July 24, 2005 6:55 PM
pezed wrote:The only way the pedal can go to the floor is a leak, either in a line , caliper/cylinder or in the master cylinder itself.


yes but wouldnt the leak be noticeable hence rob and i drove around for 20-30 mins trying to build up pressure, stopped ALOT, couldnt lock up the tires from 30mph, got back to his house pulled his trans, i went to leave and checked my fluid and it was still topped off.



Re: Brake problem...
Sunday, July 24, 2005 6:58 PM
if its leaking inside the master cylinder the fluid wont go down.



Re: Brake problem...
Sunday, July 24, 2005 7:01 PM
pezed wrote:if its leaking inside the master cylinder the fluid wont go down.


Very true, but this would be stating that we've put in 3 bad master cylinders?

We also replaced both wheel cylinders.

The only thing i can think is if the master was poorly bench bled, which I can't say becuase i didn't do it.

Joe, I would return it and say it's not working, get 1 more and i'll bench bleed it for you... If i can't get it to be fine, no one can.


Rob
'91 Beretta, 3400 and 5 speed swapped
14.553 @ 94.01 mph.
Re: Brake problem...
Sunday, July 24, 2005 7:03 PM
Well i can't thikn of anything else... i mean what else could it be??



Re: Brake problem...
Sunday, July 24, 2005 7:06 PM
In my opinion, the way our systems are designed, it can only be the master.

Proportioning valve, Meetering valve, all built into the master, The metering valve is the only one to effect the way it's braking (all front brakes, no rear)

Or the calipers, braking hard she did pull one time, but it could've been the road (aka a seized caliper)

But even still with a seized caliper it wouldn't brake the way it does. the pedal fades like it's losing fluid, but it's not. And pedal return is very slow.

It has to be the master, Just has to be.


Rob
'91 Beretta, 3400 and 5 speed swapped
14.553 @ 94.01 mph.
Re: Brake problem...
Sunday, July 24, 2005 7:11 PM
i assume you guys checked out the brake pedal assembly etc.. but i've never seen one break.



Re: Brake problem...
Sunday, July 24, 2005 7:27 PM
Yes, I inspected it today actually because i was thinking maybe the pushrod was out of adjusment ... but it's not.


Rob
'91 Beretta, 3400 and 5 speed swapped
14.553 @ 94.01 mph.

Re: Brake problem...
Tuesday, July 26, 2005 6:34 AM
Hi 90z3400

Just wondered if it was something like this.

Seems as if you have to cycle the ABS on some systems to get the air out into the lines so it can bleed out of the system.

But ignore it if it is not applicable


http://www.popularmechanics.com/automotive/sub_care_clinic/1272181.htm


Alont
Re: Brake problem...
Tuesday, July 26, 2005 7:47 AM
No ABS on a 1990. Good idea though.

My first thought was master or booster. When you bled them, were you getting good pressure at the bleeders?




Re: Brake problem...
Tuesday, July 26, 2005 8:07 AM
I'd say it's the booster, seeing as how it goes straight to the floor everytime, the booster isn't building pressure. but since I'm the only one who thinks so, pretend like I'm just a voice on your shoulder.



...yes, but is it fast?

Re: Brake problem...
Tuesday, July 26, 2005 9:26 AM
eather the master or booster (maby wrong booster)


Re: Brake problem...
Tuesday, July 26, 2005 9:59 AM
well as stated before the master and booster are new-rebuilt, with the car off the booster holds vacuum, i can pump it and it gets harder and harder, once i turn the car on it goes to the floor. Also installed new wheel cylinders cuz the one was only half working. DAMN CAR



Re: Brake problem...
Tuesday, July 26, 2005 10:32 AM
Hey aren't you so lucky that I had the very same problem this past weekend!!
I changed my rear brakes out this weekend and wasn't getting any pedal at all, as a matter of fact I was scared to stop the car at speed over 35 mph. After much work and diagnostics I found that there was an air pocket flowing back and forth between my rear brakes, after about an hour or so of bleeding the brakes I finally got it out; however, in order to do it you have to bleed just one side until the pocket comes out, you can go through a lot of fluid before that happens. Anyway, I hope this helps, thats just what happened to me this past weekend. As soon as I got the pocket out, I rebled the rear brakes on both sides and had full pedal again!


<a href="www.russelspc.com">
<img border="0" src="http://russelspc.com/jbody2.jpg">
</a>
Re: Brake problem...
Tuesday, July 26, 2005 11:12 AM
CrAzY )v(iDgEt wrote:Hey aren't you so lucky that I had the very same problem this past weekend!!
I changed my rear brakes out this weekend and wasn't getting any pedal at all, as a matter of fact I was scared to stop the car at speed over 35 mph. After much work and diagnostics I found that there was an air pocket flowing back and forth between my rear brakes, after about an hour or so of bleeding the brakes I finally got it out; however, in order to do it you have to bleed just one side until the pocket comes out, you can go through a lot of fluid before that happens. Anyway, I hope this helps, thats just what happened to me this past weekend. As soon as I got the pocket out, I rebled the rear brakes on both sides and had full pedal again!


eh always worth a try but we've bled it normally, with a pressure bleeder and gravity bleed( jack the car up and open all the valves and let it seep out. Still the same.



Re: Brake problem...
Tuesday, July 26, 2005 1:34 PM
May be a dumb question... Did you preadjust your rear brakes? No im not trying to say you are an idiot but i don't know what else to tell you.



Re: Brake problem...
Tuesday, July 26, 2005 3:11 PM
pezed wrote:May be a dumb question... Did you preadjust your rear brakes? No im not trying to say you are an idiot but i don't know what else to tell you.


lol brakes were adjusted, if anything over adjusted cuz they started to crack alittle. Im out of ideas unless this master is bad also.



Re: Brake problem...
Saturday, July 30, 2005 6:02 PM
Hey as a enthusiast I would just have to assume the master needs better bench bled ,I had the same prob with my clutch slave just a little air was all it took. If i may ask who did the motor mount conversion for your 3400, I have a enhanced 3100 vin-m block in my 89 z-24 and have a 3.4 block I'm getting ready to build just looking for advice


legacy-all

Re: Brake problem...
Saturday, July 30, 2005 6:08 PM
Also for front brakes , the steering knuckle off a 90 thru94 grand am with the calipers and rotors bolt on to the front end to give you eleven inch brakes and bigger pads for more brake sweep and then I will be converting that steering knuckle to accomadate 1.25" wide 11 inch rotors with even bigger calipers off a pontiac bonniville .


legacy-all
Re: Brake problem...
Saturday, July 30, 2005 6:10 PM
Also I'm working out rear disks off a late model trans -am by redrilling the baking plates


legacy-all
Re: Brake problem...
Saturday, July 30, 2005 6:46 PM
Cali-Cavy wrote:Also for front brakes , the steering knuckle off a 90 thru94 grand am with the calipers and rotors bolt on to the front end to give you eleven inch brakes and bigger pads for more brake sweep and then I will be converting that steering knuckle to accomadate 1.25" wide 11 inch rotors with even bigger calipers off a pontiac bonniville .


The grand am uses the same brakes as the cavalier in those years. its a 10.5" rotor i believe (same one that was on the 91+ Jbody)



Re: Brake problem...
Sunday, July 31, 2005 1:06 AM
well it's a great conversion for my 89


legacy-all
Forum Post / Reply
You must log in before you can post or reply to messages.

 

Start New Topic Advanced Search