Figured I'd just make a thread because I keep finding back an forth results...
Anyway the car is a 90 vert and recently my brake pedal has been harder with I want to say slightly less travel and definitely doesn't stop the car as well.
Wondering if it's the booster? From what I read they dont usually go bad and don't want to have to replace unless I have too because it's a PITA.
Could it be just be my master? Or a stuck caliper? I know rear calipers are missing those little clips could that have something to do with it?
Thanks for any input.
Sorry about the fairly common question but figured I'd just ask for my specific issue.

 

The first thing I would check is the check valve for the booster.

It's integrated into the hose, so take the hose of and try to blow through it, you should only be able to blow through it in 1 direction.

 

and since its intermittent, try to blow/suck though the hose a few times, if it works sometimes, you need to cycle it

 

Ok so I took the hose off the booster blowing towards the hard line I could barley blow but seemed like there was some flow not a complete vaccum.
When I took the hose of the booster it made a nice little hiss tho not sure what that means.

 

Any generic check valve will work if yours tests bad but if the valve is good, the booster is the next likely suspect.

Should the booster prove defective, now would be the time to consider upgrading the booster/MC.

 

I'll buy a new valve either way.

Tho After following the vacccum hoses from the booster to the engine I don't see any valve. Is it literally inside 0f the vaccum hoses or hardline?

 

i thought only t2s had the check valves in that hose?

 

Both my S5 NAs had the valve hidden in the hose.

 

Yeah, and judging from his test... his S5 NA does too

 

So that means check valve is ok I assume?
Booster is super rusty probably original..
On a separate note I found a blue reman tag on the front cover don't know when but whatever cool lol.

 

if you can get any air through it it's bad... I would try replacing it first.

vacuum boosters can go bad if your brake master cylinder looses it's rear seal and starts leaking brake fluid into it, which isn't uncommon. If the bottom of your booster is really rusty, I wouldn't be surprised if this happened (brake fluid strips the paint)

 

If you inadvertently have put that Rubber hose on in Reverse then your pedal gets Rock hard with almost Zero stopping power.
I mean like grabbing the wheel and pulling your weight onto the pedal to stop the car.
(hose actually has an arrow to indicate direction)

 

Thanks for the replies.
Now where would I go about sourcing a check valve can I just goto AutoZone?

 

Yup.

 

every car has a check valve, so you have brakes if the engine dies

 

Still haven't picked that up to see if There is a difference stuck with trying to remove the pilot bearing even the blind hole puller I rented won't work ffs looks like I need to break out the dremal all I have is a dam wood carving bit tho..

 

check the rubber hose between the lower manifold and the firewall, it is 25 years old and has a lifespan. i've seen a few that were hard as a rock, cracked and leaking just enough to not cause major issues with idle but give very little braking assist.