Aluminum QTU master cylinder ports?

[s10mk]

Hi everyone, I’m going to replace the brake lines on my truck, and I’m not confident that the previous owner plumbed everything correctly. It’s an 87 v10 with an aluminum master cylinder that I believe is the quick take up design. On those master cylinders, which port goes to the front wheels? Thank you!

[Keith Seymore]

The one with the big reservoir. Little reservoir is for the rear.

K

[s10mk]

Now I’m slightly confused. The front reservoir of the master is deeper than the rear, but the rear reservoir is the larger of the two. Now I’m inclined to think that the rear reservoir is for the front brakes. What do you think?

[Keith Seymore]

Yes - rear reservoir services the front brakes.

It's done that way for hood clearance (you can really see it on an Astro/Safari van master cylinder of the same era).

K

[s10mk]

Originally Posted by Keith Seymore

Yes - rear reservoir services the front brakes.

It's done that way for hood clearance (you can really see it on an Astro/Safari van master cylinder of the same era).

K

Thanks for your help Keith. I just noticed another detail when looking at original trucks. The 3/16 hardline is on the rear and the 1/4 hardline is on the front of the master. Also indicating that the rear port is for the front brakes

[s10mk]

My master cylinder was plumbed backwards by the previous owner.