68 disk/power brake conversion questions.
 

Hey guys, I got my 68 today and I'm pumped. I am looking at upgrading the factory drums up front to power disk brakes. I have read through this page --->http://67-72chevytrucks.com/vboard/s...68&postcount=4 and a few others and this is what I have decided. I wish to keep the 6 lug set up, so I guess I will need to find tie rod ends, spindles, ball joints, calipers, and lower control arms from an 88-98 2wd 6 lug chevy.
here come the questions...

what else will i need, brake lines, master cyl etc?

and what year brake booster should I be looking at.

I do have an 85 c10 I can rob parts off of, but I don't want 5 lug, and I don't want to buy that expensive 6 lug conversion kit for it.

Re: 68 disk/power brake conversion questions.
 

If you do not want to lower your truck you can use the spindles off the 85 and put new ball joints upper and lower , outer tie rods. you still have to come up with a booster and master. plus you will have to plumb all new brake lines which will include a proportioning valve.

I have had a couple friends do it this way and just buy 6 lug rotors. My one friend said next one he will just buy the kit because he ended up putting new hoses , calipers and booster and master. The only use his donor part were good for was cores because he lowered the truck with drop spindles

Re: 68 disk/power brake conversion questions.
 

What 6 lug rotors will fit the 85 spindle/caliper? I would go that rout, but tge only 6 lug rotors I found for those spindles were kits, and they were expensive.

Re: 68 disk/power brake conversion questions.
 

You can buy the rotors seperately here or search Ebay
http://www.mcgaughys-suspension.com/...rn-part-63158/
here are a set on Ebay
http://www.ebay.com/itm/MGCHEVY-6-LU...32a746&vxp=mtr

Re: 68 disk/power brake conversion questions.
 

You also need to know if the 85 has 1.25 or 1 inch thick rotors makes a difference

Re: 68 disk/power brake conversion questions.
 

Forgwt the 88-98 conversion for 6-lug,
You guys need to read and search this forum.
We have two members that have confirmed this conversion causes excessive positive camber.
The cure one member used for this problem was to remove the lower a-arm saddles and redrill the frame holes farther out.

Also forget using used parts.
The 71-72 and 73-87 parts are wore out junk and can only be used for core charges.
This is 2014.
I was doing those swaps back in the early 1980's.

Buy conversion spindles'
$229 most everywhere for standard height or 2.5" drop,
CPP has 6-lug rotors that work on all conversion spindles, all 71-72 and 73-87 HD spindles.
Look for summit racing to supply and ship these rotors fast.

There is tons of info on here.

Re: 68 disk/power brake conversion questions.
 

Re: 68 disk/power brake conversion questions.
 

Now if this guy wants to keep his stock height and has a set of Hd spindles then he can just buy the proper new parts i.e Ball joints, tie rods, and calipers. I have a theroy if you can use a perfectly good part then uses it . I will not put J/Y calipers, masters, or boosters on and vehicle but spindle sure.

Re: 68 disk/power brake conversion questions.
 

To use the 85 spindles would also require the 85 centerlink and associated steering parts. (one option)
To me is seems silly to not use a set of direct bolt on conversion spindles with no other parts change.
But he has a donor parts.
But like most of these threads there is no mention of disassembly, inspecting ALL parts, and replacing everything that is bad.
That may or may not be the case.

My opinion, the ONLY junk yard usable part is the spindle and dust shield.
Core parts for everything else.

Re: 68 disk/power brake conversion questions.
 

True I ended up with a set of 3 inch 73-87 front spindle the only drawback was they were 1 inch rotors , I only had to use outer tie rods on mine and new upper ball joints. but mine was a 72 I got the 3 inch spindles for 100 bucks with all the calipers rotors and pads all new

Re: 68 disk/power brake conversion questions.
 

Thanks for all the advice, I would use brand new parts if I had that kind of money, but unfortunately I don't. What I do have is an 85 c10 with only 79k miles on it. All of the aforementioned parts look nearly new. The truck would not pass smog and has been parked in my friends shop since 1997. He gave me the entire truck for free. I rebuilt the carb and it runs, but dumps smoke when it starts (likely valve seals) so I am giving the drice train to a friend to rebuild for his 4x4 project truck and would like to utilize as much of the rest as I can. So if I can use the spindles and brake setup, and just buy some aftermarket rotors, I will

Re: 68 disk/power brake conversion questions.
 

ALL of this info would have been good to have in the very first post of this thread.
You still want new brake hoses and everything else that looks suspcious.

Re: 68 disk/power brake conversion questions.
 

Sorry. As I said, I would like to use as much of the donor truck as possible, my 68 has a bent steering knuckle on the spindle from being hit while it was parked. I inspecred the rest of the steering parts and they seem to be ok, but if I can replace them with the newer, better parts from the 85, I would feel more at ease

Re: 68 disk/power brake conversion questions.
 

You can use all the parts from the 85.
I suggest doing that.
The 85 has to have the wider HD rotors to work with aftermarket 6-lug rotors.

Re: 68 disk/power brake conversion questions.
 

you may be able to use the 85 spindles and keep the original centerlink by using astro van inner tie rods with the 85 outer tie rods and 85 or astro tie rod sleeve.
I haven't verified that it will work yet but from what I've read and the sizes I looked up the astro tie rods will fit the 67-70 centerlink , their threads and length are the same as the 73 up inner tie rod

I would also use the brake lines and prop valve from the 85. you'll have to drill the holes in the front crossmember for the prop valve and the holes in the frame for the front brake hoses to pass through but then you can use 73 up front brake hoses instead of the adaptor hoses. the 85 rear brake line from the prop valve should go all the way to the union on the frame under the cab.

while you working on it I would also replace the lower a-arm u-bolts if they haven't already been replaced.

Re: 68 disk/power brake conversion questions.
 

What do you mean by this. How do I know if it has the hd rotors?

Re: 68 disk/power brake conversion questions.
 

Look on the rotor it should say 1.25 that is the HD rotors

Re: 68 disk/power brake conversion questions.
 

Or simply measure the rotor width.

Re: 68 disk/power brake conversion questions.
 

So... thickness?

Re: 68 disk/power brake conversion questions.
 

yes the rotor will be either 1 inch thick or 1.25 thick. You need the 1.25 thick

Re: 68 disk/power brake conversion questions.
 

so if it is only the 1" thick, I will need calipers also? or does that mean the parts are useless to me?

Re: 68 disk/power brake conversion questions.
 

with the rotors being 1 inch thick the parts are useless

Re: 68 disk/power brake conversion questions.
 

1" thick means they are the light duty version that was offered from 1981-87.
(along with the HD version)

The light duty rotors require a specific light duty:
Spindle, caliper, and one of the bearings is different.
They can still be used for 5-lug,... just not the aftermarket 6-lug rotors you are looking for.
To convert to 6-lug you will need a different spindle, caliper, bearings, and the aftermarket rotors.

Re: 68 disk/power brake conversion questions.
 

Thank you for all the useful info. I will look at them this afternoon.

Re: 68 disk/power brake conversion questions.
 

I was able to pick up and get a little better price but they are a great deal for a pair, others sell just one for what I paid for the pair


http://www.ebay.com/itm/MGCHEVY-6-LU...32a746&vxp=mtr

Re: 68 disk/power brake conversion questions.
 

ok, so the vin of the 86 (I thought it was an 85) is 1GCEC14F3GJ16####. So these are the suggested rotors from oreilly, the thickness says 1.285" so I'm assuming these are the 1 1/4 rotors I needed it to have to do the 6 lug conversion?

http://www.oreillyauto.com/site/c/de...0062&ppt=C0009

Re: 68 disk/power brake conversion questions.
 

Did you measure the rotors on your truck?
It could have had either one.

Re: 68 disk/power brake conversion questions.
 

No... I will double check them tonight