Brake compatibility with axle swap

[W20071]

Hi all. I have a 71 W200 which is retrofitted with a Dana 60 and matching rear out of a late 70s gm. There are some awesome posts on here about the crossover steering which have helped a bunch, thanks! My question however is about the brakes, The calipers and massive rear drums must require more volume than the original 4 wheel drums. Will my original master cylinder/power booster/prop valve work correctly? If not, what would be ideal to replace them with? If anyone knows or has dealt with this i would surely appreciate your advice.

[sweatybetty]

how does it work now?

[jimmy]

Not sure what you are asking.
I installed 92' Dana 60 front & 70 rear from a Dodge Cummins 250 in my 69'.
I used the factory Dodge 69' W200 power booster with a 92' Dodge 250 master cylinder. The bolt holes don't line up quit right so I filed the master holes oblong.
I also installed an adjustable rear brake proportioning valve.

Your factory drum Master will not work because it will not release the caliper pressure.

Does that help? Let us know, the guys here as very helpful.

[W20071]

Thanks, that does help. The axles are out of a 79 (i think) gm truck, I've noticed that those trucks have a considerably larger booster and master cylinder than the 71 Dodge. I have never changed any of my vehicles to disk brakes until now so it is a learning experience for me, I apologize for asking a stupid question. I am a machinist, so adapting a cylinder to fit shouldn't be a problem. I would prefer to have axles from an early Dodge Cummins but they are in high demand around here. Do you or anyone know if the master cyl from a 89-93 Dodge will work with the Dana 60 front and gm rear?

[Seff]

call a scrap yard. they might have one or 2?

[W20071]

They might have one or two of what? Drum to disk brake conversion manuals? I am sure they probably have several hundred generic motor co trucks but I guarantee that no scrap yard around here has any early Dodge Cummins trucks. It's embarrasing enough to run axles from a gm that I don't want to start changing my braking system over also. I would like to run as many factory parts as possible. Besides, the front end is still a Dana, Hopefully I can change the 14 bolt rear (or whatever they call it) to a 70 from a Dodge later on.

[Seff]

sorry i was talking about a master cylinder from a cummins. i understand what you mean by their rarity, the cheapest parts trucks where i live are around 4-5 grand not running.

[surfnuke9]

This is what I used. Required two new holes drilled below the riginal bottom two holes and drilling out the rod end to a slightly larger size.

Rockauto.com

A-1 CARDONE Part # 503360 Reman. A-1 CARDONE Vacuum Booster w/Master Cylinder

$90.79 core charge $35.00 total cost $125.79

[jimmy]

No stupid questions, ask away.
I got my master from the local auto parts store. I think it was about $20.00

Don't be bothered by using the axles. If fact I think the rear drum wheel cylinders are larger than the Dodge.

[W20071]

Thank you all for the help! I will check with my parts house for the Cardone number and for the Cummins setup.