Brake fluid leak

[schtozo]

Fluid is leaking from the bottom of #5, fitting is tight, ive never touched that piece. Yesterday i changed my master in favor of a 25mm from a 750. Brand new oem part. This morning i notice a puddle of brake fluid on the chassis underneath the master. Everything is dry on the master there is not a single leak from there, i started to touch every pipe around and felt wet under piece #5, tried to tighten the fitting but it was all good, so is it possible that regulator took a nap? I imagine changing that thing
Can be a nightmare due to location...

[jlevie]

Given where the leak is and what was just done to the car, my suspicion would be that the leak is at the master cylinder or that it is where the line from the master cylinder connects to part #5 (the brake bias valve). I can't see where anything you did would have affected the bias valve or the line from the valve to the rear wheels. But then if the brake lines are badly corroded, all bets are off.

[schtozo]

The leak is indeed from bottom of the bias valve, it has an O ring there, im dont know if its supposed to be loose or what but while touching the valve the leak was from there, as i was touching the O ring i gave it little force and it snapped out of place. I did put it back where its supposed to be. (i guess i shouldnt have been able to do that, right?)
Again, both lines that go to the master are super dry and not a single leak from there, yesterday night i dried everything in the area and left a little container over a mechanic paper towel, and this morning it was all soaked. Heavy soaked. So its leaking without any presure to it. I hope my explanation makes it easy to figure out.
My concerns are that O ring, was it supposed to be loose like for me to be able to snap it out of place?
The lines have no corrosion at all by the way!

[jlevie]

Okay, so the leak is at the bias valve. I don't know if you can easily find a replacement o-ring. But you should be able to get a used bias valve from a junkyard for $20-30.

[schtozo]

So that O ring shouldnt have snapped from place? How does it work? Whats the purpose of that o ring? Isnt it supposed to be pretty sandwished and tight between the 2 parts of the valve?

[jlevie]

The O-ring is supposed to be trapped. My guess is that someone opened up the bias valve in the past and put it back together wrong.

[schtozo]

I found a used bias from a working system, the o ring on it is pretty tight but it can be snapped out of place with some force..

[schtozo]

Ok, i attempted to remove the valve yesterday and it was such a bitch because everything is in the middle, the wrench touched everywhere leaving me no room to work at all from te top. I managed to remove the top line but the bottom was impossible, it has to be done using a lift... Plus putting back the top line was impossible to do because the valve
Moved from place a bit and now the angle with the line is not right. I had to use both hands to get it there which i couldnt do. So now im stuck with no brakes till i can take the car to a 10 mile trip to a shop with a lift. I had an idea of unhooking the line that comes from te ABS pump to te valve and tap the hole at the pump, so i can fill the system and bleed te front bakes and use it like that to take to the shop.
Questions are:
1- is it ok to do that ( using only front brakes for a 10 mile trip?)
2- what can i use to tap the ABS pump? Specific size fitting or screw?
3- do i have to disconnect the ABS pump so it doesnt activate? If so how? Remove relay?

Thank you very much for your help, Please im desperate..

[jlevie]

The valve can, with much difficulty, be changed from the top. But it is easier to do from underneath the car. A lift is great, but jackstands work okay.

The easy way to make a plug for brake lines is to cut a few inches from the end or an old hard line. Flatten the end of the tubing and weld or silver solder it up.

[schtozo]

So is my plan ok? Can i do the rear brake elimination "mod" and take it to a shop? Do i have to disable the ABS pump? Will i damage anything if i do that?

[LJ851]

My valve started leaking on my car at 160k miles and i remember being frustrated changing it.

Because of the sincere lack of pleasure while changing this component, i recommend that you install a new valve to maximize the amount of time before you will have to do the job again.