73-87 Disk brakes

[texanidiot25]

I can't seem to find the article again (my PC refuses to use the search again today), but what all is inolved in swapping in the 73+ suspension/disk brakes? Having a hard time tracking down a frame or front end with some disks.

[SCOTI]

Swap the a-arms, spindles, calipers, rotors, splash shields, flex lines, prop valve, hard-lines, tie-rods, & center/drag-link (grab the frame brake-line retaining clips while you're getting parts).

If your truck has manual steering, use the current pitman arm. If you're upgrading to pwr steering @ the same time you do the brake swap, grab the pitman arm from the donor truck (idler arms are the same).

Use a 71-72 disc/drum C10 master cyl/power booster w/the 67-72 c10-specific power brake brackets.

[texanidiot25]

Originally Posted by SCOTI

Swap the a-arms, spindles, calipers, rotors, splash shields, flex lines, prop valve, hard-lines, tie-rods, & center/drag-link (grab the frame brake-line retaining clips while you're getting parts).

If your truck has manual steering, use the current pitman arm. If you're upgrading to pwr steering @ the same time you do the brake swap, grab the pitman arm from the donor truck (idler arms are the same).

Use a 71-72 disc/drum C10 master cyl/power booster w/the 67-72 c10-specific power brake brackets.

Are you 100% this works? My dad is wondering about if brake line fittings will be the same, if the prop valve would work with the 71-72 MC/Booster.. And also which hardlines from the truck, just the front or front and rear?

He's lookin' for a 100% "this is gonna work" from some of you guys, since theres so many articles on here with many different combination.

And would the C10s or C20s have the six-lug disk brakes? When I called on junk yard, the guy got a bit uppity about me asking for a 73-87 C10 with six-lug disks, him stating only 4x4 C10s had six-lug disks. Guess I should ask for the C20s?

theres some FAQ's about this too you might want to check out

None were specific about the 73-87 for my '69. There was one about the 73-87 for the 60-66s.

[SCOTI]

Are you 100% this works? My dad is wondering about if brake line fittings will be the same, if the prop valve would work with the 71-72 MC/Booster.. And also which hardlines from the truck, just the front or front and rear?

He's lookin' for a 100% "this is gonna work" from some of you guys, since theres so many articles on here with many different combination.

I'm 100% sure it works because I did it. I had a 68 truck w/manual, 6-lug, drum brakes. I went to the wrecking yard & found a 75 GM 1/2-ton long bed truck. I pulled the front a-arms, spindles, splash-shields, rotors, calipers, wheels, master cyl, vacuum booster, prop valve, hard lines from the master to the prop valve, the hard lines from the prop valve to the front brakes, & the hard line from the prop valve to the rear. I also grabbed the tie-rods & drag-link. I didn't use the old tie-rods (I bought new ones for a 75) but did use the drag-link. It was easier @ the time to just grab the whole assembly.

I cut the hard line to the rear long enough to allow cutting it to connect to the original 68 rear coupling/splice under the pass side of the cab.

I used the calipers, master cyl, & vac booster as my core deposits for new parts. I bought rotors & calipers for a 75. I bought a master cyl for a 75 & a vac booster for a 72. I connected the m.cyl/vac booster to the hard lines & mounted the prop valve in the same place it was mounted in the 75 (front splash apron in front of the engine). I ran the front hard lines to each side of the frame just like they came off the donor truck & connected them to new rubber brakes lines (again for a 75).

I installed new bushings in the a-arms & installed them in place of my originals. I installed 73 & later dropped spindles, the drag-link from the 75, & then added the new tie-rods, rotors, & calipers to the other stuff that came from the 75.


The only thing that required some fabbing was the brake rod the goes from the pedal to the master cylinder. For that I used the original end that connected to my 68's pedal & 'spliced' it to the other end of the rod that came from the 75. My guess is a brake pedal rod from a 72 would be a direct swap but splicing was easier for me than searching for another (the original pedal rod wouldn't be long enough).

And would the C10s or C20s have the six-lug disk brakes? When I called on junk yard, the guy got a bit uppity about me asking for a 73-87 C10 with six-lug disks, him stating only 4x4 C10s had six-lug disks. Guess I should ask for the C20s?

From 73-87, 4x4's were the only 6-lug rotors direct from the factory. 88-98 Lt duty 2500's came w/a similar size rotor that's 6-lug. These rotors are not a direct swap to 73-87 spindles though. They require using an 88-98 spindle which requires more to make it work.

It would be easier to use one of the board vendors here & purchase some aftermarket 6-lug rotors that are a direct swap for 71-87 spindles.

[N2TRUX]

73-87 (73-91 for Suburbans) All C-10's are 5 lug, K-10's are 6 lug, and C/K 20's are 8 lug. Also be aware that there are standard 1" and HD 1-1/4" brakes on those year models.

If you want to stick with 6 lug you need to look at the disc brake conversion that CPP offers. This is the only conversion that will allow you to go to 6 lug disc brakes on your 69.

[texanidiot25]

Originally Posted by SCOTI

It would be easier to use one of the board vendors here & purchase some aftermarket 6-lug rotors that are a direct swap for 71-87 spindles.

By this meaning grab all the front suspension from the yard (as you did), and use rotors from the vendors? Making the junkyard 5-lug disk a 6-lug disk setup?

Who carries them? Looked through the vendors and can't find them.
And about how much total did you spend?

Thanks for all the info Scoti, I didn't mean to question your info, just need the details.

I just have a 2000 budget to finish my truck and get it on the road, so I'm looking for the budget happiest way to get it done.

[SCOTI]

By this meaning grab all the front suspension from the yard (as you did), and use rotors from the vendors? Making the junkyard 5-lug disk a 6-lug disk setup?

Yes. This nets you all of those little clips & hardware that you might not have & it's easier to find parts for the 73-87's (mainly the drag-link). The biggest difference is the prop valve os moved to the splash apron (factory location 73-87's) vs. hanging under the master cylinder (factory location 71-72's). Each of the vendors I listed here offer 'kits' that are disc upgrades w/everything needed @ decent prices. I just like getting my parts local in case there's an issue (for warranty replacement).

Edit: Who carries them? Looked through the vendors and can't find them.
And about how much total did you spend?

GMC Pauls p/n 692989 @ $100
ECE p/n 03-6370-6L $89
CPP p/n CP-4R-6 $129/pair

I set mine up as 5-lug & had about $500 in rebuilding the entire front end, upgrading to discs, & lowering the front of the truck.

[ERASER5]

X2 on what Scoti said. I had the entire frame cut off of a truck to ensure that I had ALL the parts I needed.

If you have your engine out, you can swap the entire cross member all at once. There are 14 bolts, 12 will line up perfectly, drill out the last two and you have it.

[texanidiot25]

Originally Posted by 62LS1

Since you're out of Cypress, wait until New Year's day and go to one of the two Pick-a-Part yards. They have 50% off everything (except cores) on New Year's Day only. If you go to their website, they have 'free entry' coupons to go in a day or two earlier and look for the truck you need. I don't think the free entry coupons work on the holiday.

Good Luck

Awesome idea.

http://www.houstonpickapart.com/houston.html These yards?

We had gone to Charlie's over on 2920, but he gave us another version of this swap, citing that we only needed the 73-87 spindles (but also saying a prop. valve and m/c was not needed, so rather than arguing that my dad and I just took note of this and was gonna ask else where). He was saying 35-45 perside for the spindle and brake caliper parts if I remember right.

When I called CPP to order the 73-87 six lug rotors, I asked them about that, they said the 73-87 spindles will fit the 69 control arms with 73-87 ball joints and tie rod ends..

[SCOTI]

Originally Posted by texanidiot25

Awesome idea.

http://www.houstonpickapart.com/houston.html These yards?

We had gone to Charlie's over on 2920, but he gave us another version of this swap, citing that we only needed the 73-87 spindles (but also saying a prop. valve and m/c was not needed, so rather than arguing that my dad and I just took note of this and was gonna ask else where). He was saying 35-45 perside for the spindle and brake caliper parts if I remember right.

When I called CPP to order the 73-87 six lug rotors, I asked them about that, they said the 73-87 spindles will fit the 69 control arms with 73-87 ball joints and tie rod ends..

Yes, 73-87 spindles work on earlier a-arms w/a simple swap of the BJ's. The later arms have the full rubber bushings which offer a slightly improved ride vs. the pre-73 rubber lined steel bushings. Choice is yours.....

I disagree on not needing a different master cylinder & prop valve though. Disc brakes require different fluid volumes vs drums so the later disc brake master cyl is needed. Same for the prop valve.... They're proportioned according to the brake system so the drum brake prop valve will not work efficiently on the disc set-up (it would work, it just won't work @ 100% which kind of nullifies the intention of the swap in the 1st place).

[texanidiot25]

Originally Posted by SCOTI

disagree on not needing a different master cylinder & prop valve though. Disc brakes require different fluid volumes vs drums so the later disc brake master cyl is needed. Same for the prop valve.... They're proportioned according to the brake system so the drum brake prop valve will not work efficiently on the disc set-up (it would work, it just won't work @ 100% which kind of nullifies the intention of the swap in the 1st place).

As do my dad and I. But my dad didn't bother argue on the spot about it when the guy was willing to pull the parts for us at a decent price. Trust me, the 20 year ASE Master Tech held his tongue when the guy of this yard gave his idiot's guide to how brakes work.

Think I'll just swap spindles at this moment. Less work and less money that can be used in the rest of the truck (Like tires for my 17 inch wheels). I'm moving from a 1990 Firebird, so just about every thing rides better than that sucker.



Thanks Scoti for the info, you've been a great help.

[texanidiot25]

Bought the spindles and calipers today, forgot the price but with a full set of seatbelts I left the yard minus $160, so not a bad steal at all.

The CPP rotors are MASSIVE! 12", 1-1/4 wide, about 15lbs each. Much beefier than some of the disk brakes on trucks today.

We'll start the swap next weekend.

[silver7]

Hey guys, I know this thread is old but I wanted to see if I could get some advice since I am looking at doing something very similar and going disc all the way around. I currrently have 6 lug axles drum rear (12 bolt) and disc fronts (dana 44) on a converted 71 c10 4x4. The closest kit SSBC offers for me is the 73-87 kit. Do you guys think I can do this swap without a lot of grief?

Thanks,
Shawn

[SCOTI]

Should work for you. Both are 6-lug, share common suspension parts, & would be the 1st logical choice.

[68GMCCustom]

I'm wanting to upgrade my '68's front steering and brakes. I have the bare '68 frame (my trucks body is on a '72 chassis now) that I'm going to build up. To correct the caster issue, and get the larger 1.25" disk brakes...could I just pick up a complete '73-'76 C10 crossmember, suspension, and steering to rebuild?

I guess the question being...will a later model ('73-'76) front crossmember, etc bolt right up to the '68 p/s chassis?

[FRENCHBLUE72]

Originally Posted by ERASER5

X2 on what Scoti said. I had the entire frame cut off of a truck to ensure that I had ALL the parts I needed.

If you have your engine out, you can swap the entire cross member all at once. There are 14 bolts, 12 will line up perfectly, drill out the last two and you have it.

Id say so....in response to 68gmccustom

[SCOTI]

Originally Posted by 68GMCCustom

I'm wanting to upgrade my '68's front steering and brakes. I have the bare '68 frame (my trucks body is on a '72 chassis now) that I'm going to build up. To correct the caster issue, and get the larger 1.25" disk brakes...could I just pick up a complete '73-'76 C10 crossmember, suspension, and steering to rebuild?

I guess the question being...will a later model ('73-'76) front crossmember, etc bolt right up to the '68 p/s chassis?

Yes, the later c.member will bolt-in but 2 holes usually need to be elongated on the frame. All the parts will transfer over to the original c.member as well w/o elongating the holes .

[68GMCCustom]

original crossmember is gone...and I'm trying to get started on building up the old frame w/o having to take the truck off the road.

Oh...and thanks!

[texanidiot25]

I wasn't aware of any caster issues?

Noone brought it up when I had it aligned, but maybe he just ignored it since we had the control arms off, and just countered it with shims.

Still (sadly) running the drum MC/prop setup, for the past year (yeh yeh, it's on the to-do list). It's very strong, only a few times have I wished for more power (highway mainly, but locking up at those speeds with even more powerful brakes woulda been worse anyways), but the setup has been solid and reliable.

The cheaper $100 rotors from CPP are excellent. I do pizza delivery, so it's non-stop on those brakes for several hours sometimes. No hint of fade, warping, or heat issues, and my mom's '98 GMC Jimmy's brakes can't even take that sort of driving with out getting noisy! And even with a half ton pay load they stayed pretty cool.

[nathansmith15]

Originally Posted by texanidiot25

I can't seem to find the article again (my PC refuses to use the search again today), but what all is inolved in swapping in the 73+ suspension/disk brakes? Having a hard time tracking down a frame or front end with some disks.

hey do u know if the front coils outta a 69 chevy would fit an 83 . . . i dont c how they could b very different . . . i want to cut em to lower it and dont wanna cut up my good set thats in it and the 69 is pretty much junk
let me know if u or anyone else knows thanks

[ERASER5]

They will swap. You might lose an inch or so. Maybe my '70 coils were sagging, I'm not sure, but when I put later springs in, I gained an inch or so.

[402]

SCOTI

There is nothing like experience. This information will be a great help to me on my project.

Thank You

[SCOTI]

Originally Posted by 402

SCOTI

There is nothing like experience. This information will be a great help to me on my project.

Thank You