Project: In over my head (again)

[Nailhead]

Originally Posted by Old_Red_Jeep

Is there a specific dual master cylinder to look at? At this point in the project, everything is up in the air. I figure drum brakes get a bad rap since they're more complicated than discs.

I found this somewhere on this site: NAPA 10-1371 master cylinder. It's for a '74 Corvette with non-assisted brakes, IIRC.

Mine, modified for dual-circuit operation and combined with E-350 wheel cylinders, works great.

[Don Cavey]

Another view. Do you need a throttle spring? I think I have a few. But if you have to order other stuff, you may as well get it all from them.

[Nailhead]

Originally Posted by Nailhead

I found this somewhere on this site: NAPA 10-1371 master cylinder. It's for a '74 Corvette with non-assisted brakes, IIRC.

Mine, modified for dual-circuit operation and combined with E-350 wheel cylinders, works great.

Tried to edit the above, didn't work: You'll need to run a new brake line from the rear port on the MC to the brake line going to the rear of the truck, run a line from the front port to the junction block on the frame, and plug the now-unused port on the junction block. All in (MC, 2 brake hard lines, 2 brake line reducers for the MC, a coupler for the new rear brake circuit, and a threaded brass plug) I think maybe $75 covered it.

[Old_Red_Jeep]

Originally Posted by Nailhead

Tried to edit the above, didn't work: You'll need to run a new brake line from the rear port on the MC to the brake line going to the rear of the truck, run a line from the front port to the junction block on the frame, and plug the now-unused port on the junction block. All in (MC, 2 brake hard lines, 2 brake line reducers for the MC, a coupler for the new rear brake circuit, and a threaded brass plug) I think maybe $75 covered it.

I think I'll probably go that route. You don't happen to remember the part number for the wheel cylinders? Or do you know what year e350 they are for? Will any year work?

[Von]

Originally Posted by Old_Red_Jeep

I think I'll probably go that route. You don't happen to remember the part number for the wheel cylinders? Or do you know what year e350 they are for? Will any year work?

93 E-350 with single rear wheels.
Wheel cylinder cross refernece?
Brute4c posted some part numbers farther down in that thread.

Get you a cutter drill bit for your Dremel or small drill to hog those mounting holes out. And it's worth the trouble to take the backing plates off to do the swap... it's a real hassle with the backing plates mounted on the truck.

[Nailhead]

Originally Posted by Von

93 E-350 with single rear wheels.
Wheel cylinder cross refernece?
Brute4c posted some part numbers farther down in that thread.

Get you a cutter drill bit for your Dremel or small drill to hog those mounting holes out. And it's worth the trouble to take the backing plates off to do the swap... it's a real hassle with the backing plates mounted on the truck.

Thanks Von-- that was going to be a chore to remember.

I'll add to his advice on the mounting hole modification: Unless you have a coffee can full of Dremel stones you want to expend in this operation, go get a large size chainsaw file (7/32 IIRC), cut it in half, and use it in a drill to work on those holes. This worked MUCH faster than any other method for us.

[Old_Red_Jeep]

So I've started the brake overhaul. Changing out the master cylinder was a piece of cake but these brake drums... you guys weren't kidding when you said the drum locating screws are a PITA! The first one lulled me into a false sense of security by coming out easily but the other two on the first brake had to be drilled out. I had tried everything else. On the plus side, the brake hardware looks pretty new. At least the PO seems to have kept up on some of the maintenance. I'll keep working on these brakes but I was only able to get one done in ~ 3.5 hours...

[Nailhead]

Originally Posted by Old_Red_Jeep

So I've started the brake overhaul. Changing out the master cylinder was a piece of cake but these brake drums... you guys weren't kidding when you said the drum locating screws are a PITA! The first one lulled me into a false sense of security by coming out easily but the other two on the first brake had to be drilled out. I had tried everything else. On the plus side, the brake hardware looks pretty new. At least the PO seems to have kept up on some of the maintenance. I'll keep working on these brakes but I was only able to get one done in ~ 3.5 hours...

We had to heat the holy hell out of those drum screws and use an adjustable wrench on the screwdriver to get them to budge. Dumb design.

[Old_Red_Jeep]

A quick question for you guys, Does anyone know the specs for the drum retaining screws? I can't find anything despite my best efforts. The best guess that I have is that they're 3/8"-16 thread and are 3/4" in overall length. Is this correct? I'm also planning on switching to the hex head. Thanks for the help.

[Nailhead]

Originally Posted by Old_Red_Jeep

A quick question for you guys, Does anyone know the specs for the drum retaining screws? I can't find anything despite my best efforts. The best guess that I have is that they're 3/8"-16 thread and are 3/4" in overall length. Is this correct? I'm also planning on switching to the hex head. Thanks for the help.

I measured them to be 5/16, but I could be wrong. I've got some on order from McMaster with a 3/16 socket head hex.