Break fluid leak

[Clay-Goose-Davis]

I’ve had a slow break fluid leak from my rear driver side for a little while now. I’ve already got the car up on stands doing something else, and I figured I’d get this fixed too. 

This is where the leak is coming from.

I’ve never done anything with break lines and would like some help. 
Would this be something that I could easily swap out on my own? What is it exactly? I saw there’s a hex and thought maybe it just needs to be tightened down.

 

[2seater]

It looks like it may be some sort of proportioning valve, but since the 91 has a different braking system, Bosch ABS, I cannot be certain. While the lines do not look rusty/crusty, it seems unusual for a leak to start unless something has gone wrong or work was done in that area. From the photo, it doesn't look easy to hold the valve while trying to tighten the hex without having to bend that other line out of the way?

[Ronnie]

I don't know what that line is screwing in to either. I'll bet the line has a hole rusted in it where it goes into the nut. I wouldn't want to drive the car like that.

 

If you decide to do much tightening of the fitting I would highly recommend you use a flare wrench instead of an open end wrench. Those nuts are soft metal and easy to round off with an open end wrench. Especially when they are rusty. 

[ship]

It is a proportioning valve for the Bosch brake system, part # 18020180.

[Clay-Goose-Davis]

Went in for an alignment and had Buttita Auto take a look. They say it’s missing a plug and it’s leaking from the side where the line doesn’t connect. Does this sound right?

[2seater]

It sounds odd to be missing a part unless it had been worked on recently?? I have no knowledge of the Bosch system and if you trust this shop, what do they recommend?

[Clay-Goose-Davis]

I pulled this one off of the other proportioning valve. It is made of soft rubber. It has identification markers BAF and 56. 
I wonder if there is any way to get another one of these.

[rogold]

I think this is a better pic, of course not in stock. Maybe try Ebay. ACDelco 18020180 Valve - Walmart.com

Edited April 25, 2024 by rogold

[Clay-Goose-Davis]

I swapped the rubber plug from one to the other and it stopped the leak. I just have to find another or something that will work

[2seater]

It doesn't look too sophisticated so I would think it would be a great candidate for someone with a 3D printer since you have a good sample?

Edited April 26, 2024 by 2seater

[Ronnie]

Odd that a rubber plug would be  used to stop brake fluid from coming out. I'm wondering if the rubber is intended to be a dust plug for something else that is supposed to seal the brake fluid behind it.

 

If all you need is a rubber plug, one of the "Christmas tree" style push pins like hold inner fender panels and such on might work. My local Autozone has a big selection of styles and sizes. I had to get some for my mustang to hold the trunk carpet in place when I replaced the rear shock absorbers.