dual-diaghpram brake booster" from '78 J10 truck

[blakeusa]

Know this has been discussed, but cant find the details.

i,e, Upgrade booster from a newer J10. This is for a 71 J truck w/ 4 w drums.

Was told by Kaiserman that a moderate upgrade to my 4 wheel drum brakes would be to install a 78 J10/ J20 booster in that this unit has DUAL diaphrams and produces more vac power which would help with stopping.

Want to keep the stock look for now, but would prefer to go to front disc set-up but again this is expensive and I don't want to deal with this now.

Anyone do this and was it worth it, Yes I know hydroboost would be better but want to keep the stock look. If I can get a 20 percent improvement that would work for now.

Last what exactly do I need to do this (*parts/ part number or source)- just the booster or booster and master.

All my brake lines are new SS, new prop valve, and all new drums and brakes and cylinders all around. But as we all know they don't stop heavy moving metal very well.

Ok one last to the last, someone else mentioned drilling out the drums? Never heard this one before... any value or or are they just gonna get filled with dirt and wear out.

[Stuka]

I am pretty sure the dual diaphragm boosters started in '83. I know my '81 has a single diaphragm.

But a dual diaphragm certainly makes a noticeable difference. Do you have power brakes now, or non-power brakes? Power brakes were optional until '75.

Drilling drums dates back to probably the 40's for racing. Similar to drilling rotors for better cooling. However, they will warp easier if they get to hot.

But if I was you, with a truck as nice as yours, and with that much power, I would be going disc asap. It doesn't cost that much. And could mean the difference between rear ending somebody and stoping short of doing so.

[blakeusa]

I just found this on drilled drums. Cost is 30- bucks or so per drum

http://www.chtopping.com/CustomRod4/

I also guess I need to read up on a disc brake conversion and what is a good way to go without replacing the axels

Want to keep my 5 lug rims.

[mathman]

Originally Posted by Stuka

I am pretty sure the dual diaphragm boosters started in '83. I know my '81 has a single diaphragm.

The '78 J-20 had the dual diaphragm, the J-10 had the single.

[lkmarsh]

What front axle do you have now? Ford and Dodge used five lug hubs and rotors. The Ford parts are supposed to bolt up to a D44 open knuckle. Don't have one so I don't know for sure. I do know they don't fit a closed knuckle.

[jpcoutts]

You want a booster from a J20 to get the dual daiphram. J10's didn't come with them. The dual is physically larger, you can tell by looking at them.

[babywag]

late model GW boosters are dual diaphragm, and way smaller than the 70's J20 booster.

I installed a '79 J20 booster in my '73, and it Great Googley MoogleyGreat Googley MoogleyGreat Googley MoogleyGreat Googley Moogley near hit the valve cover.

I'd go late model if I was to do the swap again.

[KaiserMan]

Originally Posted by jpcoutts

J10's didn't come with them.

Ditto that, you need one from a later J20 or from a Grand Wagoneer.

[donniesoup]

I did this swap two years ago. Very easy to do. I have 32's and it stops so much better. I got it from autozone. Threw old one in box and got core back

[Rod2]

I've posted several times about my J4000 brakes, but this is a new point that has come up. Mine came without power brakes, and the manuals were 12" drums. Over the years, I sourced at least 4 vacuum units from late '60's to '80's in preparation to power upgrade. None of them were direct bolt-ins: the firewall bolt pattern didn't match, the push rod was the wrong length, and most frequently, the push rod hole wouldn't fit the post on the brake pedal lever. I don't know what the '71 mounts are like, but they might be more like the '73 than late '70's.
I went with a hydro boost set-up from Elliot that did require redrilling mount holes, kept my drums all around, and my truck brakes are the best power brakes I've ever used.

[Stuka]

Originally Posted by Rod2

I've posted several times about my J4000 brakes, but this is a new point that has come up. Mine came without power brakes, and the manuals were 12" drums. Over the years, I sourced at least 4 vacuum units from late '60's to '80's in preparation to power upgrade. None of them were direct bolt-ins: the firewall bolt pattern didn't match, the push rod was the wrong length, and most frequently, the push rod hole wouldn't fit the post on the brake pedal lever. I don't know what the '71 mounts are like, but they might be more like the '73 than late '70's.
I went with a hydro boost set-up from Elliot that did require redrilling mount holes, kept my drums all around, and my truck brakes are the best power brakes I've ever used.

When converting from non-power brakes you basically have to swap out everything. Including the pedal rod, master cylinder, and drill holes in the firewall depending on year. I know my '75 that came with non-power brakes did NOT have the proper bolt pattern for a power booster. Never did do the swap before I sold it, but I had most of the parts for it.

[Kenall]

i have a dual booster from a 78 J20. If your rebuilding your 4000, i bet you cood find a 5 lug rotor, (bronco) slide that over you wheel hub, and fab a caliper mount

Originally Posted by blakeusa

I just found this on drilled drums. Cost is 30- bucks or so per drum

http://www.chtopping.com/CustomRod4/

I also guess I need to read up on a disc brake conversion and what is a good way to go without replacing the axels

Want to keep my 5 lug rims.