Help, no power brakes, need some suggestions.

[shawley]

I've got a 1969 C10 I just finished up, it has a 350/700R4 in it, the motor has a very very mild cam. It originally had power drum brakes, but I did a conversion on the fronts to discs from CPP, and did the CPP brake booster. The motor is not the original motor but the truck it came out of the brakes were working just fine.

So right now after finally getting the truck onto the road I have no power brakes. The booster is getting 16-17" of vac according to a test we did last night. CPP says it needs 18 to work properly, but I figured with 16-17" it should at least do something. But it doesn't do anything, the pedal is just as hard if it is running or if the truck is off.

The pedal is just extremely stiff, very hard, and feels like full manual brakes.

Any suggestions of what I can do or test? I read a thread somewhere that you can take apart the booster/master and there's a rod to adjust, but CPP has said nothing about this. We have checked the check valve and it seems to be working just fine.

I'm in Canada so its not too easy to just take it out and send away for warranty, and I highly doubt that its a bad booster, being that its brand new.

Would a vacuum canister help at all?

Thanks in advance for all your help!

This is the booster I have

[kitsbeach]

I agree that it should work at least a little bit even though your vacuum is lower than they ask for.

Maybe the pedal rod is not right.? But it does sound like a dud booster if you have vacuum on the line going to it.

[shawley]

This is what I'm getting on the gauge for the booster line

[shawley]

Booster was toast, we actually took a Snap-On scope and looked inside it, the thing is missing the internal diaphragm. So that's why I had no power brakes.

Called CPP, they were awesome and said ya we'll cover under warranty just gotta ship it back to them and they will ship me a new one. But that kinda sucks cus I'm in Canada and I just finished the truck and got it on the road and I wanna drive it. Only have a few months a year to drive it.

Went and bought a new one from a local parts company for a C10, installed it and my power brakes work 100%. Will be shipping mine back but at least I can drive it now.