02 v70 brake issue, spongy (front spring fitment) Topic is solved

Scotthmt · Post by **Scotthmt** » 08 Jul 2016, 17:28

I had my brake booster hissing, so i ordered a new booster, and figured while I'm there I may as well change the pads and rotors? Why not? Simple job right? wrong.

I got the old booster out and new one in without much trouble, bit of fighting with the typical things. Got the brakes changed with minimal trouble. Bled them.

Test run, brakes are soft and spongy, pumping them seems to stiffen it up a bit, but far from acceptable to be driving around in.

Bleed the brakes 2 more times, using 2 different methods, the hose in a bottle solo method, and the get a helper and open and close the bleeder as they hold the brake pedal down method. Even bought a vacuum bleeder.

Now I'm going crazy, why won't the brakes tighten up? there is no air in the system.

So I do research. Someone has an issue with the master not sealing on the booster, and used a bit of silicone to seal it. I give that a shot, nothing.

So here I am, not sure where to go. If this is a vacuum leak, i should head an audible hiss, i would assume. And if this is a vacuum leak, then there are only 3 places for it to leak from, the firewall, the hose off the check valve, (which has a hose clamp) or the master cylinder, which now has sealant.

Am I going crazy here?

Scotthmt · Post by **Scotthmt** » 08 Jul 2016, 18:00

Upon further research some people indicate the problem being the spring around the brake pad/caliper. I believe I have those on properly, but I will check again tomorrow.

Post by **abscate** » 09 Jul 2016, 05:46

The sponginess in the brake pedal has nothing to do with the vacuum part of the brakes. With no vacuum in the system,the brake pedal should be rock hard.

Have you changed your brake fluid every 2-3 years? Were the calipers both looking like mirrors on both sides? A sticking caliper will never bleed to the firm pedal condition.

Scotthmt · Post by **Scotthmt** » 09 Jul 2016, 08:28

Sorry I wasn't more specific, the brake hardens up with the engine off, it's when the engine is on and I am driving it that I feel the spongy-ness. I will try again today and report back my findings

Post by **MadeInJapan** » 09 Jul 2016, 11:06

I was going to mention using new fluid too. Could be the booster is in there right but the vacuum line running from it is leaking somewhere.

Scotthmt · Post by **Scotthmt** » 09 Jul 2016, 11:16

Thanks, I'll add that to things to check out. There's all New fluid in the lines, I used about 2 quarts of fluid so far. Will report back tonight.

Scotthmt · Post by **Scotthmt** » 09 Jul 2016, 20:08

Here is the update.

I removed the booster, when the leak was in fact, at the little cylinder module at the 10 oclock area of the booster. The new booster didn't have a gasket and when I removed it, the gasket stayed stuck in the old booster. So that is fixed, no more vacuum leak.

But STILL the brakes are spongy and barely engage until the pedal is deep. I rebled the brakes for the 4th time. Saw no air bubbles. Not sure where to go at this point. The brakes never felt like this prior to me changing out the rotors and pads.

I also looked at the springs on the brakes and everything is how it should be.

Scotthmt · Post by **Scotthmt** » 09 Jul 2016, 20:13

When the engine is turned off the pedal is spongy for about 2 pumps then it stiffens up

Scotthmt · Post by **Scotthmt** » 09 Jul 2016, 21:08

It was the front springs, installed wrong. Google searched for pictures of the front springs and it was clear that I had installed them incorrectly so in combination with that and vacuum leak off of the booster that was the problem

Post by **MadeInJapan** » 10 Jul 2016, 00:25

Well, glad you got it sorted out- the next thing I was going to ask you was if you used the correct DOT4 fluid!