Manual to power brake conversion

[MortamerPA]

Hello. I'm in the process of upgrading my 1982 C10 2WD shortbed from manual to power (vacuum assisted) brakes. It currently has disc fronts & drum rears, which I am not planning to change. I am planning to install a reman power booster & master cylinder, a proportional valve and booster linkage from a 1985 donor truck equipped with power brakes, and new brake lines.

The old master cylinder was attached to the firewall with 4 nuts. The power booster bracket has 6 through holes, 4 for the studs on the pedal assembly, and 2 for the firewall. The truck was factory built with manual brakes and doesn't have studs welded to the firewall. Has anybody done this swap and how did you handle this situation?

At this point, I'm thinking about just using the 4 bolts connected to the brake pedal assembly, but I'm going to take a look at the donor truck this week, provided it's still available. I greatly appreciate your feedback.

[Captkaos]

2 sets that are missing usually are on the bracket, if not use bolts and drill holes.

[MortamerPA]

Are the pedal assemblies different? I have the system all plumbed up and it seems the pin on the pedal assembly is larger than the hold in the power booster rod. I have the old rod/plunger for the manual brakes and a 1/2" bolt will slide through it, but not the pn manower brake rod.

 I've read that the brake travel distance is shorter with power than manual, however, I have not found anything about the pedal assembly.

[Captkaos]

the pedals are the same, the rod is different.

[75gmck25]

Are you sure this was delivered from the factory with disc brakes and no power assist?  I remember when disc brakes started being offered in American vehicles and they were always combined with power brakes because it required more pressure.   There is always something new to learn, but I've never seen  manual brakes with front discs in a 70's or later GM vehicle.

Bruce

[Captkaos]

Power brakes were optional on all the 1/2T trucks.  I have owned more with manual brakes than power..

[75gmck25]

So you are saying that on a square-body 1/2 ton the front disc brakes were standard, but power assist was an option?

Bruce

[Captkaos]

Yes disc brakes were standard on 1/2T trucks starting in 1970.  Power assist was optional.

[zieg85]

I prefer non-power myself.  #1- better pedal "feel" especially if something starts to leak.  #2- one less thing to go wrong. #3- pedal is the same if you loose vacuum, engine dies/large cam that doesn't provide adequate vacuum.  #4 tidier engine compartment.  #5 much easier to change out steering columns...  Every truck I've had with the vacuum power break booster leaking has been converted to non-power

[MortamerPA]

Thanks for the feedback, everybody.  The conversion went relatively smooth.  Brakes take little effort, but definitely lose feel.  Last thing is to modify the brake switch bracket or buy/make new.  Brake pedal is closer to the floor now.

Sent from my SCH-I535 using Tapatalk

[kmlubbers]

When you added the booster, was your pedal soft?

[Irish_Alley]

zieg what is involved with converting them from manual to power?
my mud truck hasnt had vacuum to it since i took it off the road years ago but i have to stand on the brakes to stop it. would manual brakes even work with 40" tires? not driving on the street but just around the mud pits