Brake issue

[vdragonmpc]

Im trying to narrow it down and desperately trying to avoid the truth....

At a light my brake pedal is easing to the floor... Is there anything besides the master cyl that would do this....

We are going to bleed it tomorrow.... But yeee gods I had other plans with the cashola a Master Cyl costs..

This car sat from Sept to a few weeks ago... Im thinking hopefully air in the lines...

V

 

[Doward]

Master cylinder leaking around the piston seal.

 

[Shytheed Dumas]

Uh, oh. I've been living with the same (minor) problem with no real sense of urgency to put it ahead of everything else I'm trying to do right now. I really hadn't planned on it being overly expensive, but your "yeee gods" has me wondering... so what's a master cylinder going for?

 

[theDon]

may want to replace your brake lines too, may be a slow/tiny leak that you don't see? You could even upgrade to stainless lines.

 

[xarewhyayen]

Whats the fluid level look like in the master cylinder? is it low? normal?
With all of the pressure in the brake system, its a small chance its a tiny leak, a tiny leak would lose alot of fluid and probably grow larger quickly if its in a softline. If your fluid isnt that low, its probably a seal in the ms. If you are low on fluid, the secondary seal on the primary cylinder is gone or you have a leak.

 

[SySt]

A master cylinder is about $100. Not like you can do much to the Supra with that much as far as mods go...

 

[IJ.]

Brakes before Mods........

 

[vdragonmpc]

Brakes before Mods........

I COMPLETELY AGREE!

This car ROLLS when you are in the wind... Stopping is a major option...

I priced the master cyl and was hittin 160$ at the dealer and 90+ at the other places...

What throws me is the resevior doesnt seem to be included. I havent had to do that lil option before...

I am not losing fliud but I am going to do a flush.... My steering is shaking and I dont like the looks of the fluid so I will be flushing that out too.... Thats some nasty a## SH&& in there... Looks like the FACTORY power steering fluid it shipped with in 91... ugh.

V

 

[monkihead]

brake booster. i had a pin hole in an old porsche of mine. it would stop the car and the pedal would fall to the floor. car would still hold, barely.

 

[vdragonmpc]

brake booster. i had a pin hole in an old porsche of mine. it would stop the car and the pedal would fall to the floor. car would still hold, barely.

Well the car had fine brakes until it sat while I did the headgasket, turbo, exhaust and suspension mods...

Now it eases to the floor.... Its acting like I drove down a mountain and I orginally thought I had a stuck caliper...

Whats maddening is its not consistant. Its not doing it all the time... Today its fine. (but raining)

V

 

[monkihead]

Well the car had fine brakes until it sat while I did the headgasket, turbo, exhaust and suspension mods...

Now it eases to the floor.... Its acting like I drove down a mountain and I orginally thought I had a stuck caliper...

Whats maddening is its not consistant. Its not doing it all the time... Today its fine. (but raining)

V

ah, definitely check the master cylinder. my old teacher used to say,"give it the finger test". stick ya finger in the master cylinder, if you get black stuff on you-its time for a rebuild. or buy it rebuilt.

 

[IJ.]

Dragon: What you describe is "Pedal Retention" this is enough to fail your car in a roadside check by the Law and you won't be driving it anywhere if you get pulled over!

Brake fluid is "Hygroscopic" meaning it attracts water like you wouldn't believe, while the car was sitting this water collects and sits in one place causing pitting of the master cylinder bore and you get the Brake version of Blowby just like a tired motor!

(I spent a few years in the brake industry as a kid and can't stress enough how important it is to flush fluids each year or so as it will save you 1000's in the long run)