Civd16y8

Hey guys Im lost on this one. I have a 93 Vx hatch and the brakes suck on it. They dont grab until almost the floor. I checked all the brake pads and rotors they are all good. I put 3 different master cylinders in it bled all the lines still no brakes? When the car is running and I pump them it makes it idle funny. Like from 1g to 2g fluctuating? Ive done everything someone please help me out here!!!!

kkim

did you bench bleed the master cylinders before installing them?

Civd16y8

Ya I did, with every master cylinder before installing we did. Im so lost...

kkim

check your brake booster as it is assisted by vacuum and it sounds like you might have a leaky line or blown diaphram in it.

Disconnect the vacuum line from the intake manifold to the booster, plug the line at the manifold and see if stepping on the brake changes the idle. I bet the idle stays the same. From there, you need to check out what part of the booster is bad. I know there is an inline one way valve in the vacuum line... that may be bad. If not, most likely the booster diaphram.

Paprika

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Civd16y8 &raquo;</TD></TR><TR><TD CLASS="quote">Hey guys Im lost on this one. I have a 93 Vx hatch and the brakes suck on it. They dont grab until almost the floor. I checked all the brake pads and rotors they are all good. I put 3 different master cylinders in it bled all the lines still no brakes? When the car is running and I pump them it makes it idle funny. Like from 1g to 2g fluctuating? Ive done everything someone please help me out here!!!!</TD></TR></TABLE>
I have a very very similar problem. But I think my break booster is OK. I'll monitor this thread but if you come up with anything let me know too. This is dangerous.

Civd16y8

Haha tried it, I took out the little grey piece that goes from the vaccum line to the brake booster. I had really good vaccum and when I did that the brakes were hard like they should be. Tried a different little grey piece off another eg no difference at all....Thanks for the help lemme know if u got anything else...

kkim

then i would start suspecting a bad brake booster w/ something wrong internally.

Civd16y8

THAT WOULD BE THE BLACK CIRCLE BOX THAT THE MASTER CYLINDER CONNECTS TO RIGHT?

kkim

yes.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Civd16y8 &raquo;</TD></TR><TR><TD CLASS="quote">THAT WOULD BE THE BLACK CIRCLE BOX THAT THE MASTER CYLINDER CONNECTS TO RIGHT?</TD></TR></TABLE>


http://autorepair.about.com/cs...a.htm


http://www.procarcare.com/incl....html

Paprika

Can someone explain to me why a bad break booster or how a bad break booster can affect how far you have to push the pedal to slow down? I'd think that if the booster was bad it'll just be harder to push the pedal down since you don't have the vaccume assistance. No?

kkim

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Civd16y8 &raquo;</TD></TR><TR><TD CLASS="quote">Haha tried it, I took out the little grey piece that goes from the vaccum line to the brake booster. I had really good vaccum and when I did that the brakes were hard like they should be. Tried a different little grey piece off another eg no difference at all....Thanks for the help lemme know if u got anything else...</TD></TR></TABLE>

Paprika- Yes, I misread Civd16y8's answer on checking the booster. He needs to check if his idle still varies from 1-2k, when he has the booster vacuum line removed and the intake manifold spigot plugged, while the brakes are being pumped. Sorry for the confusion. He left out that piece of information and I assumed he was saying it was okay.

Paprika

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kkim &raquo;</TD></TR><TR><TD CLASS="quote">

Paprika- Yes, I misread Civd16y8's answer on checking the booster. He needs to check if his idle still varies from 1-2k, when he has the booster vacuum line removed and the intake manifold spigot plugged, while the brakes are being pumped. Sorry for the confusion. He left out that piece of information and I assumed he was saying it was okay.</TD></TR></TABLE>

Yeah I'd think if it still varies it's an electrical issue, no?

kkim

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Paprika &raquo;</TD></TR><TR><TD CLASS="quote">

Yeah I'd think if it still varies it's an electrical issue, no?</TD></TR></TABLE>

Possible, but hard to say at this point. If he disconnects the booster completely from the intake mani, plugs the the hole in the mani, then has no weird idling problems, I would think it safe to look at the booster (and associated parts) as the possible source of his brake and idling problem... though he may have multiple problems, too.

I try to troubleshoot one problem at a time so as not to end up confusing the symptoms.