I know this question has been asked before but I'm still not 100% positive about one thing. I'm swapping my 85 GS drum rear for an 84 GSL disc rear. All the calipers have been rebuilt and I have a rebuilt master cylinder that is designed for rear disc GSL braking system. Okay, my question is this, can I use my GS proportioning valve or do I need to get a GSL valve. I have an attached a pic of the item in question circled in white. Thanks!

 

I would guess that you need the new proportioning valve, because that'll balance out the front/rear brake bias. At least I *think* that's what performs the bias.

 

I think Barwick is right, but not sure. The only reason why I say this is it doesnt look like mine?

 

Hmmmm.... I just dug into my files and found a PDF that I downloaded a while ago with exploded views. I forget where I downloaded it from but it looks legit. In any case, they have exploded views of both the "drum" and "disk" braking systems and the part number "43900A" for the "Valve P.B." is shown on both. So according to that the parts are the same.

 

yeah looks the same as the one on my 85 gsl, just took it right now. im a little bored

 

Another thing..... my new rebuilt master cylinder "the one designed for rear discs" did not come with one of these little collars. The line mates up fine but does anyone know what the exact purpose of this is?

 

no idea what collar you are talking about or what it does, but if it works it works right?

 

Well, to be honest, I don't know if it works. Tonight's when I bleed my brakes and take 'ol rex for it's first spin. Thing is... if this part is functional other than just being an adapter I don't wanna find out at 60mpg. Know what I mean?

I am seriously "chomp'n at the bit" to get my car on the road.

- LSD rear
- Rebuilt disc brakes all 'round
- Energy Suspension bushings
- Tokiko Blues
- Eibach Pro-kit
- 205/60-13 Sumitomo HTR 200's