Manual Front disk brakes
 

Has anyone herd of manual front disks in 1969 / 1970 trucks? A guy I work with has two.

Re: Manual Front disk brakes
 

No disc brakes till 71..

Re: Manual Front disk brakes
 

Yep. And as far as I know, there were no manual discs, only power front discs.

OP, it sounds like that guy either converted those trucks to front discs, or a previous owner did.

Re: Manual Front disk brakes
 

Power brakes were only an option for C10 in 71 and 72. On C20 and heavier they were always power. I have manual disc brakes on my 69 that I upgraded from 71 parts. I recommend manual for a C10. The pedal effort is quite light, and the system is simpler.

Re: Manual Front disk brakes
 

I had a 71 GMC 1500 with manual front discs. They require a special master cylinder.

Re: Manual Front disk brakes
 

My 71 has factory non power disc brakes.

Re: Manual Front disk brakes
 

Disc brakes became standard in 1971, no 1/2 ton with front drums after 1970.
Manual disc brakes were available in 1971 and 1972. Seen lots if them.

I started a thread about this subject, years ago.

I sold auto parts from 1985-1998, an independent parts store, not a chain. We sold Wagner brake parts. Their catalog listed disc brakes as optional in 1970. I don't have the catalog any more.........
Had a customer come in my store. He was snotty with me, from the get go. He said I WANT front brakes for my 1970 C10, AND IT DOES NOT HAVE SHOES!!!

I said my catalog lists disc brakes as an option in 1970. I knew this because I was REAL interested in converting my 68 to disc, was sick and tired of those POC no stopping front drum brakes!!!
The pads listed for the 70 were the same D52 pads used in 1971 all the way to 1987.

I made him a loyal customer!!!

Many on my other thread say his pickup was likely converted. I AM NOT arguing that point, since NO ONE has produced a 70 C10 with disc brakes. It would be on the SPID decal??? wouldn't it, if a pickup had such option.

I've given up hope for any 70's made with the ALLEGED optional disc brakes.

1973 may haven had manual disc brakes...if I still had a catalog...

70's with disc brakes MUST have been a REAL RARE option, if it is true.

I plan to equip my 67 and 68 C-10s with manual disc brakes, once back on the road.

Re: Manual Front disk brakes
 

Special as in you can't just find it by application in any parts store (except one in your neighborhood). You had to work diligently with a NAPA owner to dig up cross references about what part fits the manual brakes application for 71-72 manual front disc/rear drum brake application. You probably found the last parts store guy who could help any of us out, and all others in the country have been messed up for a long time and lost the correct parts reference probably since before they were computerized. Thanks for researching that. https://67-72chevytrucks.com/vboard/...39#post9169739

Re: Manual Front disk brakes
 

Guys, thanks for correcting my statement about power front discs. Sometimes when I open my trap, I am mistaken. And not too stubborn to admit it, or too old to learn. :chevy:

Re: Manual Front disk brakes
 

You're not alone, bud. I make mistakes here all the time, and I was a state-licensed mechanic when these critters were new! I guess I'm getting senile (speaking only for myself).

Re: Manual Front disk brakes
 

There's lots of interesting info involving brakes here on the forum. Not long ago there was a thread about front drum brake option in 71-72. And another recent thread about which trucks in 71 got a metering valve included in the combination valve. There's lots of little tidbits of info, but no grand encyclopedia about brakes on these trucks to bring it all together.

Re: Manual Front disk brakes
 

Manual disc masters were available in the square-bodies too-I think all the sway to '87 but don't hold me to that. Somewhere along the line they went from cast to aluminum. A '73 master is a unicorn. Most use a '74 up which is a little different but can work (see photo of a '73 with '74 master). If you look really carefully the PO used adapters to keep the lines from crossing which is how I initially put it back, but actually if you take the adapters out the lines went onto the correct reservoir for front and back. I swapped them after this photo was taken and they bled much nicer.

Re: Manual Front disk brakes
 

Using the correct master from a non power square body may also give you the correct bias. I don't see a proportion valve in the photo above. I suspect the bore in the master is different, front and rear curcuit, to compensate.

Re: Manual Front disk brakes
 

Prop valve mounts on the frame on a square body.

If you pull up a photo of a '73 master the big and small chambers are reversed from the '74 master shown. The PO of this truck must have changed the master and wanted to keep the lines looking straight so he adapted up and down when all he had to do was cross the lines and they bolted right up. The front line to the big reservoir and the rear line to the smaller reservoir.

Re: Manual Front disk brakes
 

I would guess it was converted and i bet it was a 5 lug also. I can't believe it would have been an option in 70 with 6 lugs. (on a 2 wd) I think it showed in some books as an option on elcaminos which were with the truck parts sometimes.