hosrom_951

Merry Christmas all, hope you are all enjoying the holidays......

Brakes are not quite doing what they are supposed to. Here is a list of what i have done and i hope that you guys would chime in if i missed anything:

1) Replace Brake Fluid
2) Bleed Brake System
3) Check Front and Rear Rotors (Disks)
4) Check Front and Rear Brake Pads
5) Check All Hoses/Connections For Signs of Leaks

The rotors (disks) are OEM standard, no grooves or signs of wear. The pads are Mintex orange, nice and fat in the front and rear. The brake pedal is nice and firm (used to be spongy, replaced the fluid and bleed the system and problem solved).

However, i still have to 'press hard' say 1/2 way (as in push the pedal 1/2 way before reaching the end) in order to get some good stopping power. I took of the intake manifold to see and check the venturi/brake booster lines, all fine.

So what's the problem? master cylinder? bias valve? pistons? calipers? There are NO leaks and everything looks fine, what could it be? any ideas?

TIA!!

mochman

as in pedal has too travel too far as distance or hard too press

hosrom_951

More like hard to press

Darius Juca

you might no be getting brake booster assistance...at lest if you press hard it will stop...other sypmtom would not be good...your lines might be clogged dirty,or brake booster....

Jason_86_951

Sounds like the check valve on the brake booster is shot, give it a check.

hosrom_951

How to check the brake booster check valve? i tried removing the brake booster line and heard a hissing noise comming from that valve. Also i still couldn't get that hose off, i don't want to get agressive and tear off the hose (it's old and hard).

FSAEracer03

First of all, what were the conditions it started in? Was this after some work on the car? Was it after railing hard on the brakes in a panic stop? Was it after a "spirited" run? Was it random?

It's hard to diagnose any problem without some background info first said.

hosrom_951

Kevin: It happens under any driving condition...........offcourse the brakes are not that well when the car is cold, as it warms up, it gets better but as described above.

Jaak Lepson

Could be the master cylinder. Mine went this past summer and I only had 1/2 the braking power. It seems I had to push harder to get the car to stop. Check the MC and see if there is little tiny pieces of black rubber floating around ... this is usually the first visable sign.

I upgraded my MC to the 87+ version as the bore goes from 17mm to 25 mm IIRC. I seem to have better brake performance. I also flushed the brake fluid until it came out clean.

This was the problem in my case ... your may be different.

Jaak Lepson

Happy Holidays!!!!!!!!!!!!

hosrom_951

Jaak,
Now, you said to check for black pieces of rubber, not black dirt that is held in the 'filter' right? becaused i HAD that before fludshing the brake system. Again i shall check the fluid reserviour and maybe get a new check-valve since they are cheap and easy fix.

Thanks

Jaak Lepson

That black dirt IS rubber ... MC is toast!!! Time to get the newer version for 87+ years.

Hint: connect the lines first before mounting the MC ... will be easier!!

Jaak

hosrom_951

Jaak Lepson

And flush the system real good. Order a large bottle ... makes a difference!

Jaak

hosrom_951

87+ for turbo or NA? i found from Paragon that the turbo was the same (all years) unless i am mistaken?

Jaak Lepson

87+ for Turbo IIRC ... 86 was different ... has a different number. My garage ordered it for me and there was two numbers ... one for 86 and another for 87 and up.

Jaak