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Loss of vacuum at brakes by Kitskaboodle
Started on: 10-17-2020 10:51 PM
Replies: 2 (68 views)
Last post by: theogre on 10-18-2020 01:35 AM
Kitskaboodle
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Report this Post10-17-2020 10:51 PM Click Here to See the Profile for KitskaboodleClick Here to Email KitskaboodleSend a Private Message to KitskaboodleEdit/Delete MessageReply w/QuoteDirect Link to This Post
Hi guys, I have an issue with my brakes that I’m unsure as to what the problem is.
After a highway cruise, getting off the freeway and taking the exit ramp, as I first press the brake it’s kind of spongy and goes a little too close to the floor. I will then pump the pedal once or twice and it will pump up so to speak a little better and braking will then be somewhat ok. (braking has never been good on this car anyways) Anyways, since brake action gets somewhat better with just two pumps, I am suspecting the check valve or booster. Air in the lines I’m not so sure of but haven’t checked. As an FYI I replaced the booster and m/c about 1 and a half years ago.
Your thoughts on this?
Thanks, Kit
My bad..,,, 85 GT auto / all stock brakes

[This message has been edited by Kitskaboodle (edited 10-17-2020).]

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fierosound
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Report this Post10-17-2020 11:37 PM Click Here to See the Profile for fierosoundClick Here to visit fierosound's HomePageClick Here to Email fierosoundSend a Private Message to fierosoundEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Kitskaboodle:

As an FYI I replaced the booster and m/c about 1 and a half years ago.


Had same thing on my Indy - lost vacuum to booster. . Brake vacuum tube filter plugged.
When the diaphram in the booster deteriorates, the rubber dust gets sucked toward the engine and the filter does its job (and gets plugged).

Easiest thing to check first.

Take the filter out, disconnect line at booster end, and blast the line clean with compressed air.
You may be able to blow filter clean in reverse direction. Or just install a new one.



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theogre
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Report this Post10-18-2020 01:35 AM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
Booster Problems Will Not made you to "pump the brakes" for any Low Pedal problems.
Booster w/o Vacuum can, often will, made you "Stand on the pedal" often w/ both feet and even then barely stop the car. Try push the pedal w/ engine off... Booster w/ good check valve keeps enough vacuum to let you push easy ~ 1 to 3 times then gets very hard to push. But You having Low Pedal maybe only 1 time then goes hard to push.

IOW Something else is wrong...

If your not leaking fluid anywhere you see then:
Iffy rear pistons causing too much pad clearance.
Iffy MC w/ bad seals internally.
or Both.
(Most likely, can be other issues too adding to low pedal.)

Worse... likely you have Pad(s) Dragging and "After a highway cruise..." the Brake Fluid can Boil as caliper(s) get hot. Very easy w/ old wet fluid.
See my Cave, Brake Fluid
and http://www.fiero.nl/forum/Forum2/HTML/144456.html
Pad Dragging can warp rotor(s) or even cause a Fire and has done this to many people not just Fiero owners.

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[This message has been edited by theogre (edited 10-18-2020).]

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