Brake problem
 

I took my truck('65 C10) for it's second second shake down drive today. The first one, the brakes were not working right, they didn't feel like they had the power boost. So, today I checked to make sure the booster was getting vacuum and, it is. But the brakes definitely didn't have the power brake feel. The booster was installed new about 4 years ago, but the truck has sat since then. What is the next thing to check? Could I have got a bad booster?

Re: Brake problem
 

Start your tuck with your foot on the brake. If the pedal goes down when it starts, your booster is working.

Re: Brake problem
 

Check the check valve?

Re: Brake problem
 

Thank you, Richard, I'll check it out.

Re: Brake problem
 

Thanks for the tip, I'll check it out. What am I looking for (I know what the check valve is)? When I pull it out from the booster. How do I test it?

Edit: I did a Google search and found out how to test it.

Re: Brake problem
 

Well, when I started the truck with my foot on the brake pedal, it didn't go down. Also, when I killed it with my foot on the pedal, it stayed up. When I pulled the check valve out of the booster, you could hear the hiss of air going into the booster so, apparently it's holding vacuum. But, the brakes aren't working like power brakes should. What could be wrong? I'm sitting here scratching my head wondering what's going on.

Re: Brake problem
 

Did you drill a hole in the brake pedal 1" lower than the factory non power brake hole? If not, you don't have the correct pedal leverage ratio and it will never feel right.

Re: Brake problem
 

is this needed for all conversion? i just did the power conversion using CPP parts. brakes work great maybe a little to great.

Re: Brake problem
 

Yes, I did drill that hole.

Re: Brake problem
 

Its recommended. Drilling a hole 1" down from the original hole will make the brakes less touchy. It does this because it takes away a bit of leverage that the brake lever has on the master cylinder.

Re: Brake problem
 

Been doing some research on brake issues and, I'm wondering if the push rod is not adjusted correctly. Anyone have brake issues because of this?

Re: Brake problem
 

We really need more info: disc or drum? split front-and-rear system, or original single system? what make and year master? make and year booster? Pics would help a lot. Using an equalizer-block between output lines from Master and remainder of system?

Given this extra info may enable us to hit the mark and help.
Sam

Re: Brake problem
 

It's disc front, drum rear. System is split. Don't know the make or year of master or booster. They were both purchased new about four years ago. The truck has not be driven since the installation. The truck is out in Bowie so, can't tell you the make of each till tomorrow when I go back out to work on it again. There is an equalizer in the system. I'll take pictures when I go back and I'll see what make they both are. Thanks for the help!

Re: Brake problem
 

Here's pictures of master cylinder and brake booster. Can't see anything that says what brand these parts are.

Re: Brake problem
 

Man, I feel your pain. I'm fighting the same thing. Here's one of the best diags I've found which happens to be my parts too:
http://www.classicperform.com/TechBo...htm#rightvalve

My mechanic says the travel (assuming the booster is ok) might be a brake not moving properly due to blockage, leak, stuck...yada. He suggested clamping the flex hose(s) to isolate which wheel. My rear only has one flex hose at the tee. And with posi trac, I can't rotate just one wheel. When I clamped that hose, I had little pedal travel. So, I'm thinking one of my cylinders is sticking. I noticed a difference in travel with shoe adjustment, but I don't think that's all. I might go ahead and replace them since they don't look as new as the rest and I can clean the lines out more.

I hope this helps. Good luck and keep us posted

Re: Brake problem
 

UPDATE: I replaced the rear brake cylinders last night and that helped a little but didn't really solve the problem.

wrt to the troubleshooting link I sent, I fail Test 1 of the booster test, but not the others.

Any progress on yours?

Re: Brake problem
 

I had a friend check it out today and, he thinks it might not have enough vacuum. In the next couple days I'll borrow a vacuum tester and find out. If that's the problem, I guess I'll have to decide if I'll go with a vacuum pump or a vacuum manifold.

Re: Brake problem
 

Is your booster a single or dual diaphram booster?

Re: Brake problem
 

I don't know. How do you tell?

Re: Brake problem
 

I'm wondering if it might be good, to move the master cylinder rod in the brake arm, back up to the original hole to gain leverage on the master cylinder, if nothing else improves brake function. Just a thought.

Re: Brake problem
 

I was wondering that too. I don't think mine has another hole. I'd lover to hear if that helps. Seems like it may be a bandaid for the real problem though.

Re: Brake problem
 

I think you're probably right.

Brake problem
 

I have a problem with my rear brakes on a 1965 C30 panel. It has the stock rear end. When I bought it the RR brake was locking up. We did a complete brake job, replacing everything, front, rear and master cyl. The problem is, on both sides of the rear brakes, the shoes will not come together all the way. The top is spaced out about 1/8". It was that way when we took it apart too. The wheel cly's are new, from NAPA. It seems that the wheel cyl are not collapsing all the way. Are there different wheel cyl for this truck? The new ones are the same as the old ones.

Re: Brake problem
 

Hope I'm not coming across as an ass, but It really would have been better IMHO, if you had started another thread to address your problem, instead of putting it in this thread. This thread is about the brake problem I am having, and it's not the same issue as Yours. You will most likely have a lot more responses to your brake problem by starting your own thread.