Hello all! I've decided to go ahead and convert my dana 70 rear drums to discs on my 79 F250. I've already replaced the master cylinder, so i guess I'm out that money since it's set up for disc/drum system.

My question is, what MC will I need to run the new disc/disc system? And can I run the same dual piston calipers on the rear that I have on the front?

 

Kevin, are you sure you have a Dana 70? I may be wrong, but think its more than likely a Dana 60. Is your truck 2wd or 4x4? My 4x4 (79 f-250 4x4) has a dana 60. Anyhow, not sure if the stuff they sell is the same for a 70 and a 60, but there are lots of companies that manufacture the mounting brackets you will need for this swap. You will need the mounting brackets and bolts (usually sold with the brackets), front axle calipers and hardware for a mid 80s chevy truck (3/4 ton), pads and rotors for same model/year. I personally have not done the swap but its on the to do list. As to you wanting to run the dual piston calipers like on the front of your truck I don't know of any company that makes brackets for that swap. Your best bet is to do the chevy swap. You don't need to change your MC, you might get by with leaving everything the way it is now. Worst case scenario, is you get done bolting everything on and the rear brake pressure is too high and your rear brakes drag. In that case, you will want to install an pressure-adjustable proportioning valve thats like 80 bucks.

 

I bought the brackets from Great Lakes off road, a company who advertises on Ebay, for $45, plus shipping. You can use three different calipers: the chevy front ones as mentioned by previous member, or GM ebrake ones from a 75-78 Caddy El dorado, or, if you want to keep the ebrake, and don't want to mess with Caddy ones, there is a company called TSM, who redesigns the Caddy calipers to make them user friendly, and a bolt on operation.

You don't need the dual plunger calipers on the rear. The rear brakes are only doing about 40% of the work. The chevy calipers that work are designed for the front of a 3/4 ton truck! They are way over designed for the rear.

The Chevy calipers, rebuilt, cost about $25 each, with core, iirc. The Caddy's run about the same from a j/y, and then take untold hours of rebuilding, searching for parts,etc, and don't end up working right. The TSM calipers will run you $300+, but bolt on without problem, and work great, with ebrake. You can see why most members use the chevy ones.

Some guys need the adjustable proportioning box, some not. If you do, there is a co. in orange,CA, ABS brakes, who sells a nice one for $50.

I did the conversion and still was not satisfied. Ultimately, I converted to a hydroboost system and that brought the brakes into the new century. Now they are one of the best features of the truck. It stops on a dime.

If you do a search, there is a lot of information about the swap in an old thread I wrote, with photos.

Good luck. k

 

great lakes, ruffstuff, and DIY4X all sell the brackets you need.

 

Thank you gentlemen. This is exactly info I was looking for! And I think it's a D70 because of the extra material of the housing around the diff cover. Can't put up pics cuz I'm on my phone.