Power brakes but not so powerfull

[LeDevil]

I have a 67' C10 with power brakes and well up until tonight I thought I had manual brakes. The brake pedal only moves about 1/2 a inch and when pressed I have to put quite a bit of effort in pressing the pedal to stop the truck. The truck feels like it wants to jump some times when sitting at a light. What should I look for to fix my issue? Thanks LeDevil

[chrismoore701]

2 things in my opinion, I guess one question and one thought. Do you have 4 wheel drums? I would say it could be a vacum leak?

[kizer]

1/2 inch of slop moment in the brake pedal before the brakes activate or you only have a total of 1/2 of movement in the brake pedal total?

[LeDevil]

chrismoore701: Yes it has 4 wheel drums, Where would you think the vacuum leak would be? How would I check for that?

kizer: I have a total of 1/2 inch of movement there is no slop.

Thanks for the reply's guys

[lolife99]

swap to disc brakes up front.

[umwtnt]

If I remember correctly, you should be able to put your foot on the brake pedal with the engine off, Start the engine and the pedal should go down some. If it doesn't then your power brake unit is bad. You can check the hose to the unit for vacuum leaks.

[chrismoore701]

My dad has a corvette with 4 wheel drum, not power, and you better pray if you need to stop fast. As for checking for vacume leaks, what I do is take a can of carb cleaner and spray near the vacume hose, if there is a leak, it will suck the cleaner into the engine and the engine will rev higher. check the hose and connections. good luck

[HotRodYJ]

Originally Posted by LeDevil

...The truck feels like it wants to jump some times when sitting at a light. What should I look for to fix my issue? Thanks LeDevil

I'm guessing automatic? Sounds like the idle might be a bit high compounding the problem.