R&P GM 1/4 Ton Disc Conversion

Post Script parts list for R&P 1/4 ton disc conversion:
So, here are the final parts and pieces I found useful to complete this project - and I guess I should copy this up to the first post as well:

R&P 1/4 ton disc brake kit (although I ordered this from Rich at his new venture called R&P Early Jeeps, I assume its the same as the original R&P 4wd set-up)....probably depending on what you order from Rich, it seems people get more or less parts, depending on how 'complete' of a kit they want. But the basic idea is that the custom caliper brackets are the key part to get from R&P, and the rest you can get from FLAPS:
1) caliper brackets - custom from R&P
2) rotors - I got mine along with the caliper brackets from Rich, so not sure exactly what they come from. I think they are from something like a 1990 Suzuki Samarai - the typical GM s-10 rotors don't have large enough center bore to fit over Jeep hubs)
https://www.rockauto.com/en/catalog/suzuki,1990,samurai,1.3l+l4,1271179,brake+&+wheel+hub,rotor,1896
3) Calipers - I used Carquest 18-4129 (left) and 18-4128 (right)
4) Brake Pads - D154 (organic - only found these through O-riellys)
5) Brake Lines - Summit Racing 230910 - these worked out really well as they work with 7/16 in. banjo bolt at the caliper end and female 3/8 in -24 inverted flare on the other (to connect to my traditional hard line). 15.75 in. length seems really good and is a bit shorter than many of the other options, so less excess hose to deal with.
6) Wheel studs - Dorman 610-260....I still had the OEM style wheel studs and Wagner brake drums pressed on the back of the hub....I needed a longer wheel stud to work going through the rotor and using a thicker modern mag wheel with acorn nut. If still using a thin steel wheel or shanked lug nuts, maybe not necessary....These Dormans have a very short section of knurl as I initially concerned the knurl could protrude through the hub and engage into the outboard rotor, but the rotor was counterbored so this wasn't as big of an issue as I was thinking.
7) Knuckle Studs...3/8" - 24 x 1.5" I did the buttonhead knuckle studs conversion at the same time, and as the caliper bracket is 1/4' thick, I went with a 1/4" longer buttonhead to 1.5" length bolt to ensure it would go through the caliper bracket and leave enough thread to nut off properly. I used metal lock nuts on mine, but there was enough thread you could use a standard lock washer if preferred.....

Here is where the original thread started out:
Starting to put together and walk through what is needed for a 1/4ton GM disc brake conversion (front) - Richard at R&P has helped me out with this. It uses the S10 style calipers that require a 10mm banjo type fitting....I think this would be the standard flex hose section connecting from the hard line to the caliper:
https://www.summitracing.com/parts/dhb-h38107/make/chevrolet/model/s10/year/1990#overview

So what I am still trying to figure out is how to connect the flex hose to the hard brake line, which IIRC is 3/16" hardline - so I think that is 3/8-24 male inverted flare thread. Seems like there is probably some combination of fitting adapters could possibly work, but I am not sure what the thread is for the non-banjo end of the hose, and so far, not finding any obvious adapters. Or do you all know of a different hose connection that will work with female flare on one end and banjo on the other?

 

looks like I need something like this:
https://www.speedwaymotors.com/Spee...dUWhFyObGqlPYbzCL55TN_yW8BWxUZzxoCbHgQAvD_BwE

 

sometimes it takes a bit to figure out how or what to search for....finding some better options now...this is looking even better:
https://www.speedwaymotors.com/DOT-Braided-Stainless-Brake-Hoses-1978-88-GM-10mm-1-5,5059.html

 

I'll send him a note - but since its sat, I wouldn't expect him to get back to me for a couple days. So digging around on my own.....
I am ordering the 184128/184129 calipers he lists which I believe use a 10mm bango fitting and the D154 pads (its hard to find organic - so will be picking those up locally at Oriellys - thinking I might get 2 sets so I have one for future use).
He also listed the longer knuckle studs for the disks, but I'll go with the buttonheads of the same length....
Will need longer wheel lug studs (though this is maybe due to my wheels as opposed to just the addition of the rotor....a few measurements will hopefully clarify.
What I don't have any info on is the flex hose, and if there is any additional mounting hardware needed for the caliper to the bracket.

 

I am using a Willwood MC that Rich sells as part of his dual res MC conversion...I bought it a few years ago and set up as drum/drum (and that is how its been used for the last couple years), but supposedly I should be able to remove the RPV on the front to make it work with the disk....not entirely sure if I will need to replace the RPV, or just go without. These are the details I am trying to work through ahead of time....Rich's info sheet is a bit 'thin' - probably assumes the client knows something about what they are doing.

 

Here is a more budget option...but 18" long a lot
http://www.partsmike.com/index.php/products/bh-

looks like sam is selling them even cheaper:
https://stores.partsdude4x4.net/brake-lines-pair-for-disc-brake-18-long-hsdbk/

 

thank you! I'll look into it

 

Starting to make a bit of progress doing some dry fitting so I can figure out some details.....
After disassembly of the knuckle, I had to press out the wheel studs that hold the drum to the backside of the wheel hub. I was worried I might have to deal with swaging, but somebody had already taken care of that and everything came apart without too much hassle.
Next, started with studding the knuckles - this is all the usual with using button head bolts. Spot faced the inside of the knuckle, tried to lightly flare/counterbore/drill out the first thread or so to allow the button head to sit flush, and also ground down the diameter of the head to under .625" which was the diameter of my spot facing tool. Didn't put the loc-tite in yet as I wanted to make sure the length was appropriate - used 1.5" long bolts instead of the standard 1.25" as these will have the thicker brake caliper bracket instead of the thin drum backing plate. Seems like it came out good:



As many of you know from researching disc brakes set-ups, there are a few different options, all with some advantages and disadvantages. An advantage of the 1/4 ton (S10) GM style with R&Ps kit is the rotor fits outside of the wheel hub. Obviously, this makes it easier to change or machine the rotors without having to disassemble the hubs etc, and it allows use of the old hubs that are not machined smooth on the backside. Also, no grinding is needed on the knuckle for caliper clearance....

Going through a bit of a dry fit, the spindle (and camber shim under the spindle) go on the knuckle:


Then the R&P caliper - I am not sure if this is something Rich has made, or if its some manufacturer style production......But it seems these are kind of the key to being able to go with an externally mounted rotor.


Now we check the length of the knuckle studs - seems good. This will use grade 8 metal lock nuts for final assembly.


Put on the wheel hub....clearance was tighter than I expected between the nuts and hub, but should be fine:


Put the rotor on - all seems to be fine:



And the caliper (no pads)....no interference with knuckle:

 

So now, my next question is related to the lug/wheel studs. I am going to need a longer stud than the OEM ones (or maybe whatever it was that came out). With the old set-up, I was already a bit short given the thicker aftermarket alloy rims and tapered lug nuts (as opposed to the shank style nuts on the CJ). Yes, removing the drum gives just a bit of length, but the addition of the rotor adds more than the drum removes, and don't think I'd trust the lug nuts if I lost a few turns of thread. Also, the knurled section of the OEM style lug studs has more length (.425") than just the thickness of the hub, as it originally went through both the drum and hub, and thus if used, the rotor would get caught on the knurl that sticks through the hub. It looks like I am going to need a lug nut with no more than .375" knurled section.....


so how does one search for lug nuts - is there a spec chart somewhere that I am not finding?
Looking for:
1/2x20
.62 knurl diameter
.375 knurl length immediately below the head
total underhead length of 1.5" (including knurl), although a bit longer would be okay.

 

Yes...it's just a matter of finding them in a search system that isn't really set up for non-application specific searching. I am finding quite a few direct line connections, but it's the lengths that is not ideal....most are in the 15-20" range. May be better with short OEM style hose and banjo adapter on one end. If my current hoses were decent, that is probably the route I'd go, but they need replaced so was looking at other options.