Brake problem

['65 chevy lover]

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?

[Richard2112]

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

[rvrfoot]

Check the check valve?

['65 chevy lover]

Originally Posted by Richard2112

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

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

['65 chevy lover]

Originally Posted by rvrfoot

Check the check valve?

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.

['65 chevy lover]

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.

[chevy_mike]

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.

[mehoff400]

Originally Posted by chevy_mike

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.

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

['65 chevy lover]

Originally Posted by chevy_mike

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.

Yes, I did drill that hole.

['65 chevy lover]

Originally Posted by mehoff400

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

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.

['65 chevy lover]

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?

[luvbowties]

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

['65 chevy lover]

Originally Posted by luvbowties

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

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!

['65 chevy lover]

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

[highwinger]

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

[highwinger]

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?

['65 chevy lover]

Originally Posted by highwinger

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?

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.

[Captainfab]

Is your booster a single or dual diaphram booster?

['65 chevy lover]

Originally Posted by Captainfab

Is your booster a single or dual diaphram booster?

I don't know. How do you tell?

['65 chevy lover]

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.

[highwinger]

Originally Posted by '65 chevy lover

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.

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.

['65 chevy lover]

Originally Posted by highwinger

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.

I think you're probably right.

[Magic Bus]

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.

['65 chevy lover]

Originally Posted by Magic Bus

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.

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.