C30 disk brake swap questions

[Alan's Classic]

Thank you so much Kevin.

[Alan's Classic]

Wheel bearings and seals are the same like you said. I compared the 1976 C20 burb to a 76 C30 on Oreillys web site.

[tincan1966]

Alan;
When I switched my '69 to disc I used everything from a '73 c-30. My donor had the large JB-8 brakes. I went all new thru O'Reilly's using Dorman upper and lower control arms, brake best hubs and rotors and brake best select pads. It was all a bolt on, I retained my '69 crossmember.

[Alan's Classic]

Originally Posted by tincan1966

Alan;
When I switched my '69 to disc I used everything from a '73 c-30. My donor had the large JB-8 brakes. I went all new thru O'Reilly's using Dorman upper and lower control arms, brake best hubs and rotors and brake best select pads. It was all a bolt on, I retained my '69 crossmember.

How can you tell if they are the large brakes JB-8? Are they only on C30's?

[tincan1966]

I am not certain how many years ran the JB-8 I do know that 1976 did.
The Caliper pistons are 3 3/8" for the JB 8 and 2 15/16" for standard.

My truck was a 14000 GVW so I wanted all the brakes I could get. I also did a disc swap on the rear after I switched to a corporate 14 bolt rear axle.

[Captainfab]

All the C30 dually's I have seen use a different design caliper and corresponding spindle. These apparently have been the JB/JD8 option. They don't mount with the typical slide bolts, They use a sort of wedge and a retaining bolt as shown here.



So I guess it boils down to what capacity you need and what spindles you get. The other thing I would check is the thickness of the rotors.

[tincan1966]

That's what I have Captain. They work great, but a hint of advice- make sure to use anti-seize on the slides, as this type is really exposed and will rust quickly.

[Alan's Classic]

Originally Posted by tincan1966

I am not certain how many years ran the JB-8 I do know that 1976 did.
The Caliper pistons are 3 3/8" for the JB 8 and 2 15/16" for standard.

My truck was a 14000 GVW so I wanted all the brakes I could get. I also did a disc swap on the rear after I switched to a corporate 14 bolt rear axle.

Originally Posted by Captainfab

All the C30 dually's I have seen use a different design caliper and corresponding spindle. These apparently have been the JB/JD8 option. They don't mount with the typical slide bolts, They use a sort of wedge and a retaining bolt as shown here.



So I guess it boils down to what capacity you need and what spindles you get. The other thing I would check is the thickness of the rotors.

Thank you fellers!! The hunt continues.

[Alan's Classic]

CJRacing15 fellow member has offer to help out with my quest for disc brake conversion. It's from a 1983 P30. It even has hydroboost. The pic of the caliper looks like a JB8 caliper. Hard to tell. Thoughts from what you see in the pics.

Can I use my 1968 crossmember with this setup?

[Captainfab]

All of that should bolt right up to your '68 crossmember. You will likely need to drill out the LCA shaft U-bolt holes as the newer ones are larger in diameter. I do recommend using the larger ones. You can also use that hydroboost and master cylinder if you like on your '68. The brackets I sell make it a bolt on installation, except for lengthening the pushrod.

[Alan's Classic]

Originally Posted by Captainfab

All of that should bolt right up to your '68 crossmember. You will likely need to drill out the LCA shaft U-bolt holes as the newer ones are larger in diameter. I do recommend using the larger ones. You can also use that hydroboost and master cylinder if you like on your '68. The brackets I sell make it a bolt on installation, except for lengthening the pushrod.

Thank you John. If things go as planned I will be in touch with you about a bracket

[BMERDOC]

I told Ian he lit a fire with his first post. I guess he hasn't come back to check. I steered him towards a local 83(?) hub-to-hub crossmember and diff sold by a forum member. He picked it up over the weekend. Looks like he is off to a good start.

[tincan1966]

I tried for about a year to sell the complete new hub to hub C 30 front end I have, now have decided I am looking for a truck to fit my front end! Going to start with it and build from there.

Alan, if I can help in any way with part numbers, etc, hit me up- be glad to help.

[Alan's Classic]

Originally Posted by tincan1966

I tried for about a year to sell the complete new hub to hub C 30 front end I have, now have decided I am looking for a truck to fit my front end! Going to start with it and build from there.

Alan, if I can help in any way with part numbers, etc, hit me up- be glad to help.

Thank you Sir, I will keep that in mind.