hunter29078
1/2 ton status
If I convert my rear drum to a disk using the plates from diy4x will I still have an emergency brake?? What will I need to do to fab one?? Thanks
CK5
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14 bolt rear disk conversion emergency brake???
- Thread starter hunter29078
- Start date
Muddytazz
1 ton status
76-78 caddy eldorado calipers will give you the ebrake.
K5dreamer
1/2 ton status
Im running into the same issue. the short answer is no, using the brackets and front calipers you no longer have a parking brake. Obviously an automatic transmission can simply be put in "park" so ill assume were talking about a manual (im planning on doing a NV4500 swap to get rid of my TH400).
options i have come across are as follows......
1. caddy calipers - gives you a mechanical (cable) parking brake. downside, many guys dont think they provide enough clamp. which makes me nervous.
2. transfer case brake. - downside, apparently expensive. a custom rotor that mounts to the output yoke of the transfer case. with a cable actuated caliper that clamps down on the yoke rotor.
3. a bit more complicated, and what im going to look at tomorrow, is grabbing disk brakes off of a newer style 14bff axle, and seeing if they can be grafted onto a drum brake axle. in my case, a D70HD. Newer style brakes use whats called a Drum In Hat (DIH) rotor, with a non parking brake caliper on the rotor, and a drum style brake for the parking brake built into the rotors center, which is cable operated.
4. Line lock - using the line lock for a parking brake instead of burnouts. some claim they will hold for weeks on end, others have voiced concern about bleeding down pressure, or more to the point voiding the reason for a parking break. AKA if your hydrolics fail, you have no backup cable operated system.
5. carry around chock blocks, and hammer them under the tires to hold the truck in place, park the truck up against an object such as a tree, rock, cliff, street curb, or honda, or find some other way to keep the truck from rolling away under its own weight.
6. for a manual truck, put it in 4wheel low, first gear, and turn the front tires all the way either left or right.
options i have come across are as follows......
1. caddy calipers - gives you a mechanical (cable) parking brake. downside, many guys dont think they provide enough clamp. which makes me nervous.
2. transfer case brake. - downside, apparently expensive. a custom rotor that mounts to the output yoke of the transfer case. with a cable actuated caliper that clamps down on the yoke rotor.
3. a bit more complicated, and what im going to look at tomorrow, is grabbing disk brakes off of a newer style 14bff axle, and seeing if they can be grafted onto a drum brake axle. in my case, a D70HD. Newer style brakes use whats called a Drum In Hat (DIH) rotor, with a non parking brake caliper on the rotor, and a drum style brake for the parking brake built into the rotors center, which is cable operated.
4. Line lock - using the line lock for a parking brake instead of burnouts. some claim they will hold for weeks on end, others have voiced concern about bleeding down pressure, or more to the point voiding the reason for a parking break. AKA if your hydrolics fail, you have no backup cable operated system.
5. carry around chock blocks, and hammer them under the tires to hold the truck in place, park the truck up against an object such as a tree, rock, cliff, street curb, or honda, or find some other way to keep the truck from rolling away under its own weight.
6. for a manual truck, put it in 4wheel low, first gear, and turn the front tires all the way either left or right.
hunter29078
1/2 ton status
Let me know what you find out about this one and if you start a thread please let me know. Thanks.
K5dreamer
1/2 ton status
will do, as of now i dont even know if the axle in question has disks. it just looked like a relatively new truck, (short order cook truck) that had full floaters. so i didnt get under it to see what it had. it may very well have drums, but well see. Even if i get it all home, i may only be able to take rough measurements to see if there is any compatability, may not have any solid info for a while.
JOES89K5
1/2 ton status
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Brakes
K-dreamer you should just find a 14 bolt rear from a newer truck . I am not sure when gm started using rear disk brakes w e-brake but it would probably be the way to go if you want to do it right. You will have more time and money spent on all different modifications.i am thinking of my options and are going to go with a newer rear. I have located one just gotta make the move. It cant be that hard to make slight modification like moving spring perchs. I AM HIGHLY MOTIVATED.
K-dreamer you should just find a 14 bolt rear from a newer truck . I am not sure when gm started using rear disk brakes w e-brake but it would probably be the way to go if you want to do it right. You will have more time and money spent on all different modifications.i am thinking of my options and are going to go with a newer rear. I have located one just gotta make the move. It cant be that hard to make slight modification like moving spring perchs. I AM HIGHLY MOTIVATED.
K5dreamer
1/2 ton status
Totally appriciate the concern and advice guys, sure alot of guys on here know my situation but....
im running D70HD DRW axle from a K30 with a matching DRW D60 up front in order to run H1 rims without recentering or backspacing. (if i build another blazer, ill probably go SRW with non-beadlock steelies, but i wanted military rims on my military truck). The D60/D70HD axles came as a matched set, from the same truck, for a great price, so i didnt keep looking around for a newer 14bff with disks.
OK so... just got back from junkyard #1....
I got the SRW hubs from a 14bff axle out of a 1998 G-van, got the axle shafts too, all for $53. I didnt think about it till i got home, but these are newer style hubs, that the drums slide onto, as opposed to being "bolted" to with the lugnut studs like they do on the older style.
Now, at this junkyard i couldnt find a FF axle (D60/D70/14bff) with disk brakes... however i found what i think is a 3/4 ton 14bsf axle with 8 lugs and the DIH disk brakes. It was marked as coming off of a 2000 GMC truck. I worked for a while, and managed to get one side kinda taken apart, but didnt have all the necessary tools to get it completely apart. and had a date at the shooting range so i had to leave.
Major points i noticed.
1. the rotors from the 3/4 ton axle do of course fit onto the FF hubs.
2. BUT the hubs are much thicker from the front surface to the back of the flange, which limits the depth the parking brake can get to.
3. On the 3/4 ton rotor, the depth of the parking brake drum is 3in. which matches the measurement from the WMS to the inner side of the parking brake shoe on the 3/4 ton axle.
4. the depth of the SRW hub is 2in, giving only 1in for the parking brake shoe to grab onto. the parking brake shoe is 1-3/4 inch wide. so that means about half the parking brake shoe would engage the rotor, meaning half the holding force of the factory setup.
5. the BIGGEST problem i see, is the mounting flanges for the two axles. the 1998 G-van drum axle has tiny mounting plates for the backing plates. using maybe 13mm or 15mm bolts to hold it on, and the flange is maybe 3/8in thick. The 2000 GMC truck axle has a HUGE mounting flange which uses big studs and 24mm nuts to hold the caliper bracket and parking brake parts onto the axle, and that flange was maybe 1/2-5/8in thick.
I obviously have no faith in tiny flange and bolts to hold what a huge flange and 24mm nuts held on. But I think A relatively skilled welder could weld the caliper bracket to the axle tube and solve the problem.
or an adapter plate of 1/2-5/8in billit could be made in a way that the center is "notched" or "hollowed out" so that the smaller flange fits inside of it snuggly, so any rotational force is not carried by the little bolts, and is transfered directly into the welded on flange. and the little bolts simply hold the adapter onto the flange. and then the caliper bracket mounts to the adaptor.
So in short, the disk brake setup from a 3/4 ton SF 14bff could work with some sort of adaptor, but it would be kinda half assed with that limited engagement of the parking brake shoes.
the other option would be to try and install the rotor on the back side of the hub, im not sure exactly how that would work though...... if you just use longer studs, or what the deal would be.
NOW...... im waiting on a callback from junkyard #2, they apparently just got a crap ton of trucks in for cash for clunkers, and i asked them to check if they had any GM FF axles with disk brakes, and if they do ill go check those out and see what were dealing with.
And just to add more confusion, there was a burned out Ford Excursion on the lot, which had full float rear axles, but i didnt know what kind of axle it was, but they were 8 lug, full float, DIH brakes. Although the ford used a single piston caliper, the 3/4 ton GM axle was dual piston, which i like better.
WHEW!!! can ya tell its been a busy morning?
im running D70HD DRW axle from a K30 with a matching DRW D60 up front in order to run H1 rims without recentering or backspacing. (if i build another blazer, ill probably go SRW with non-beadlock steelies, but i wanted military rims on my military truck). The D60/D70HD axles came as a matched set, from the same truck, for a great price, so i didnt keep looking around for a newer 14bff with disks.
OK so... just got back from junkyard #1....
I got the SRW hubs from a 14bff axle out of a 1998 G-van, got the axle shafts too, all for $53. I didnt think about it till i got home, but these are newer style hubs, that the drums slide onto, as opposed to being "bolted" to with the lugnut studs like they do on the older style.
Now, at this junkyard i couldnt find a FF axle (D60/D70/14bff) with disk brakes... however i found what i think is a 3/4 ton 14bsf axle with 8 lugs and the DIH disk brakes. It was marked as coming off of a 2000 GMC truck. I worked for a while, and managed to get one side kinda taken apart, but didnt have all the necessary tools to get it completely apart. and had a date at the shooting range so i had to leave.
Major points i noticed.
1. the rotors from the 3/4 ton axle do of course fit onto the FF hubs.
2. BUT the hubs are much thicker from the front surface to the back of the flange, which limits the depth the parking brake can get to.
3. On the 3/4 ton rotor, the depth of the parking brake drum is 3in. which matches the measurement from the WMS to the inner side of the parking brake shoe on the 3/4 ton axle.
4. the depth of the SRW hub is 2in, giving only 1in for the parking brake shoe to grab onto. the parking brake shoe is 1-3/4 inch wide. so that means about half the parking brake shoe would engage the rotor, meaning half the holding force of the factory setup.
5. the BIGGEST problem i see, is the mounting flanges for the two axles. the 1998 G-van drum axle has tiny mounting plates for the backing plates. using maybe 13mm or 15mm bolts to hold it on, and the flange is maybe 3/8in thick. The 2000 GMC truck axle has a HUGE mounting flange which uses big studs and 24mm nuts to hold the caliper bracket and parking brake parts onto the axle, and that flange was maybe 1/2-5/8in thick.
I obviously have no faith in tiny flange and bolts to hold what a huge flange and 24mm nuts held on. But I think A relatively skilled welder could weld the caliper bracket to the axle tube and solve the problem.
or an adapter plate of 1/2-5/8in billit could be made in a way that the center is "notched" or "hollowed out" so that the smaller flange fits inside of it snuggly, so any rotational force is not carried by the little bolts, and is transfered directly into the welded on flange. and the little bolts simply hold the adapter onto the flange. and then the caliper bracket mounts to the adaptor.
So in short, the disk brake setup from a 3/4 ton SF 14bff could work with some sort of adaptor, but it would be kinda half assed with that limited engagement of the parking brake shoes.
the other option would be to try and install the rotor on the back side of the hub, im not sure exactly how that would work though...... if you just use longer studs, or what the deal would be.
NOW...... im waiting on a callback from junkyard #2, they apparently just got a crap ton of trucks in for cash for clunkers, and i asked them to check if they had any GM FF axles with disk brakes, and if they do ill go check those out and see what were dealing with.
And just to add more confusion, there was a burned out Ford Excursion on the lot, which had full float rear axles, but i didnt know what kind of axle it was, but they were 8 lug, full float, DIH brakes. Although the ford used a single piston caliper, the 3/4 ton GM axle was dual piston, which i like better.
WHEW!!! can ya tell its been a busy morning?
K5dreamer
1/2 ton status
ok... the ONLY FF rear axle in the area with disk brakes is from a 2003 2500 series pickup. the guy wont sell the brakes, and wants $1500 for the axle 
so sorry guys, someone else is gonna have to pioneer fitting the full float disk brakes to the drum style axles.
Me, imma check the lot hours, and if theres enough time today, pick up those 3/4 ton brakes, and see if i can make them fit onto the D70HD axle.
so sorry guys, someone else is gonna have to pioneer fitting the full float disk brakes to the drum style axles. Me, imma check the lot hours, and if theres enough time today, pick up those 3/4 ton brakes, and see if i can make them fit onto the D70HD axle.
K5dreamer
1/2 ton status
ok, so i bought as much of the 3/4 ton stuff as i could, ill have to go back friday as i couldnt get the parking brake plates and such off the axle (yard closed) but i got the rotors, calipers, and parking brake shoes from one side. Ill try and take some pics for showing how it all fits together.
My first attempt to test fit had me slipping the rotor over the outside of the SRW hub, and that led me to think it wouldnt be ideal.... however, after seeing this picture online....
i see i can indeed mount the rotor to the backside of the hub if i can get the right lugnut studs... meaning i could put the parking brake shoe fully inside the DIH rotor. Its simply a matter of sorting out how to mount the factory backing-plate/caliper-mount in such a way as to accomplish this goal.
Ill try and do some measurements once i have all the parts together.
My first attempt to test fit had me slipping the rotor over the outside of the SRW hub, and that led me to think it wouldnt be ideal.... however, after seeing this picture online....
i see i can indeed mount the rotor to the backside of the hub if i can get the right lugnut studs... meaning i could put the parking brake shoe fully inside the DIH rotor. Its simply a matter of sorting out how to mount the factory backing-plate/caliper-mount in such a way as to accomplish this goal.
Ill try and do some measurements once i have all the parts together.
I think that Excursion would have the metric bolt pattern. You'd have to either re-drill for the 8 on 6.5 or change rims.
K5dreamer
1/2 ton status
ah, good to know, good thing im against putting ford parts on my chevy (i may do the stupid dooty shocks with my 4in lift though) otherwise i may have some frustraiting work ahead of me......oh wait..... i always have that..... did i mention my speedometer worked on the way to the junkyard.... and didnt work on the way home 
K5dreamer
1/2 ton status
ok, well, i may have bought these SRW hubs for no reason. I was looking at the wheel bolts to figure out which ones id want to use, and turns out GM went metric on me. The thread, length, and diameter of the wheel bolts in the hub i bought off the 1998 G-van axle are different from the ones in my 1984 (1985?) K30 axles. Ill be comparing diameters today, and hopefully, its just a matter of drilling the hubs out for the older style bolts, otherwise, i just waisted $53 bucks for some large oily paperweights
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