Question for those with front disc and rear drum.

[Lugnutz65]

If you have disc front and drum rear, what hard line are you running to the rear wheel cylinders? 1/4" or 3/16"?

I'm about to plumb new hard line. I'm keeping my original 1965 rear drums. I'm nearly 100% sure my rear drums have the stock setup with 3/16" hard line running back from the common 1/4" front drum line.

Has anyone switched their rear drums to 1/4" line? My new front disc brakes will be 3/16" line. The MC uses a 1/4" line for the rear brakes and I was thinking of switching the rear drums to 1/4".

[scoot_mcgrute]

I did factory replacement lines down the frame and on the axle and they are 1/4" on the frame and 3/16" from the tee fitting to the wheel cylinders. I'm running a 1" Wilwood master, 1/4" to the front calipers as well and seems to have good pedal thus far. I'll find out for real when I get it on the road soon

[canadian_diesel1964]

I have the 96 blazer set up and I'm 1/4 to 3/16 in the rear...3/16 to 3/16 split to front...worked great

[canadian_diesel1964]

By the way Lugnutz I'm dropping my T 5 in next week...the clutch is in..thank you your blog helped me a ton!

[jayoldschool]

My 65 was 3/16 from the front to all the way to the back. Don't think it will make a difference once you start swapping components. Just make sure you have your lines connected correctly.

[vetnat]

1961 GMC - I'm in the process of doing disc conversion on the front, keeping the drums in the rear. I have figured: 3/16 to the front discs, 1/4 from proportioning valve to rear brake hose, then 3/16 to wheel cylinders. Strange thing is, I ordered replacement rear axle brake lines from Classic Industries, and they sent 1/4", which does not fit. Waiting to hear from customer service.

[racecougar]

I'm running 1/4" down the frame to the rear brake hose, then 3/16" from the tee on the axle to the wheel cylinders.

[vetnat]

Found this post over on the square body forums. It appears that those trucks had 1/4 line splitting into 3/16 for the rear. So, if using a proportioning valve made for a square body truck, should be golden.

Originally Posted by 1984Silverado4x4

These trucks use 1/4 in steel line along the frame rail. When it splits at the rear axle to go to the two wheels its 3/16 steel line.

Dont know what length you need. I just bought a couple of pre flared lines and if I needed any more just went back to the parts store and got what length I thought I needed.

A little warning with the pre flared lines though.
I replaced all the brake lines front to back on a teachers truck and every single one of the connections leaked because the second flare was bad so I had to reflare the lines myself.

The other trucks that Ive done I just bought a roll of brake line and cut and flared it myself.

[Lugnutz65]

Just an update for those who are following this thread.

I went to the salvage yard today and confirmed a few things about the 1995 Blazer brakes. The Blazer uses a 1/4" line from the MC to the PV and then to the antilock mechanism box. Then more 1/4" line along the frame rail to the rear brake hose. Then it changes to 3/16" from the brake hose to the rear drums. The Blazer front brake circuit is all 3/16".

Why all the fuss? Well I just wanted to make sure the Blazer PV would function properly since I plan to keep my 3/16" brake lines that are currently on my 1965 C10.