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Discussion Starter #1
So, car has very very soft brake pedal, no brakes until end of travel.

po put in a janky connector on the vacuum line then slid the damn vacuum line over another erxisting line, leaving a big ol vacuum leak. Anyone know where this line is going?
back of the motor, behind the throttle body, to the right goes to the brake power booster, to the left???
 

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That one is supposed to go to a one-way vacuum diaphragm tee that feeds a vacuum storage canister and HVAC head, which actuates the air vent deflection doors.
 

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Could be a bad master cylinder, low brake fluid, or drums out of adjustment. Not sure what years got drums. I'm thinking 89-93
 

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And ABS, based on the booster and MC. :)
 

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Discussion Starter #6
So I looked into this a bit further last night.

It's a 1996 V8.
when on, the pedal is soft and goes to the floor before I have very weak brakes.
When off, the pedal is hard after a few pumps.

Fluid is BLACK in the master reservoir.
And very very low. I'll top it off and bleed brakes to confirm before I buy a new booster as they are pricey compared to a new master cylinder.

If I do replace the master cylinder, what is the procedure to try keep as much air out as possible?
 

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While bleeding, just do a fluid change.

This is easier done with a vacuum or pressure bleeder; but you can gravity bleed also, just be aware you'll have to keep it topped off.

And you'll be bleeding the passenger rear first, letting it run until it's the color of the new brake fluid.

As to have to keep as much air as possible out; again, if you replace the master cylinder, use that as a good time to bleed the entire system.

Do you have ABS? If so, it's even worse; you really need to find someone with the exerciser and have them bleed the system complete with the ABS to get IT flushed out also.

RwP
 

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The problem is not low fluid - besides the brake light should have come on if it was actually low.

I would listen for a hissing sound when holding the brake pedal on - from the booster. Helps if you have a second person to listen.

Also, check the brake hoses at the wheels. One might be swollen.

If you get a new booster - DON'T get a Cardone. Replace both the booster and master cyl at the same time. Bench bleed the master cylinder before installing.

Al
 

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Discussion Starter #9
dash is lit up like a christmas tree right now.
The front lines were replaced 3 years ago when I last had it, need to see about the rear lines. ( I cannot remember if I replaced it.)

I do have ABS. pretty sure NO one has the exciter anymore...
I need to find a new resevoir too. (it is 21 years old, it's due) seems like the non-abs ones are the only ones available.
 

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dash is lit up like a christmas tree right now.
The front lines were replaced 3 years ago when I last had it, need to see about the rear lines. ( I cannot remember if I replaced it.)

I do have ABS. pretty sure NO one has the exciter anymore...
I need to find a new resevoir too. (it is 21 years old, it's due) seems like the non-abs ones are the only ones available.
Yah. That reservoir may be hard to find brand new; OTOH, there's a few other vehicles that should cross in. Crown Vics and GMs come to mind, since they use the exact same master cylinder.

BIG hint - pick up the Factory Service Manual; make the rod tool (a template made out of cardboard!), and adjust the rod before you bolt it all up together.

As to the exciter; there was one guy had one here, and someone else was working on an Arduino replacement.

I can find them used online; but for $400, I'd rather pay someone else to do the work.

RwP
 

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Discussion Starter #12
So, we return,

looks like the driver's side caliper is leaking fluid. It looks pretty wet some I'm betting when the po changed the pads (he assured me recently) he must have damaged the piston seals...

looks like my front wheel pattern change got pushed up in schedule.
 

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Well, at least you identified the problem, and it's pretty straightforward. A lot of times, you can chase sub-par braking performance for a while before finding the culprit.

One new caliper, bleed the whole system, and you should be good to go.

Al
 

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Discussion Starter #15
I thought I'd need to change rotors to do the pbr?
I need to replace wheels so I was going to do the hub swap at the same time.

I.e. Powerstop: More Information for POWER STOP KC1304C
though the core price for those almost doubles the price...
I may cheap out and do this kit.
http://www.rockauto.com/en/moreinfo.php?pk=7595644&cc=1354733&jsn=5130

If you have to buy a new caliper, it's time to do the PBR brake mod.

New PBR's are about the same cost.


They come to $145

More Information for POWER STOP S4838

A set of Ours at equivalent quality is $80

More Information for POWER STOP S4378

Most of the difference is in the core charge, lol.
 
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