Brakes

[profe56]

Today I had and still having a problem with my c10 69. the brake pedal went down all the way when I wanted make a stop, I pushed the brake pedal three or more times and was OK but that happen again, I checked the brake fluid level in the master cylinder and is full. then I did inspect the hoses and lines and everything is OK also the brake light turned on when the pedal went down. Can you help me please

[Old Yeller 1970]

Time for a rebuilt master cylinder.

[bucketObolts]

Mine did the same minus the brake light

[profe56]

Thanks: I'll start to check for prices for rebuilded or kits.

[treveiger]

Not to steal the thread but would a rebuilt manual breaks stop as good as power breaks?

[dmack91]

Originally Posted by treveiger

Not to steal the thread but would a rebuilt manual breaks stop as good as power breaks?

Some say yes. I rebuilt mine, bled them, and it stopped OK, but not as well as I had hoped.

I then added a booster set-up off of an old truck. Now it stops nearly as well as my 99 Dodge. Not bad considering my Chev is 43 years old and has 4 wheel drums IMO.

[Longhorn Man]

manual brakes do not stop in as short a distance as power. They are less likely to lock up in a panic situation, and that'll help you mainatain control.

As for the OP, is your pedal going to the floor when you first hit the brakes, and then you pump it up and they work fine?
or
When sitting at a light, the pedal drifts down to the floor and you have to pump it up to get your brakes back?

You didn't give enough info to say "needs a new master".

[profe56]

I push the pedal and brakes OK but if I hold the pedal breaking in a stop for example,the pedal stars to go down slowly and then the brakes light turn on.
there is no leaking fluid or broken hose or line.

[Wrenchbender Ret]

You definitly have an internal leak in the master cyl. Put a new or reman. on as soon as pos.

[treveiger]

Ya it sounds like a leak somewhere.

[profe56]

thanks, specially if the master is leaking behind but again I did check the fluid level and is OK.
thanks again

[Longhorn Man]

it is time to replace the master cylinder. They are very inexpensive and easy to replace

[Old Yeller 1970]

profe56, when master cylinders go bad they don't leak externally. You'll never "see" a leak. The leak is past the seals inside the master cylinder. The fact that you're not seeing leaking fluid anywhere but your brake pedal goes to the floor is what tells us it's a defective master cylinder.

[sstone69]

I did mine on my 69 - CST back in March. Around $40 from NAPA. First thing my son and I did on the truck after washing it.

[70cst]

Originally Posted by Longhorn Man

it is time to replace the master cylinder. They are very inexpensive and easy to replace

Good point plus...This is better than hitting another truck or car due to bad breaks.

[Longhorn Man]

Originally Posted by Old Yeller 1970

profe56, when master cylinders go bad they don't leak externally. You'll never "see" a leak. The leak is past the seals inside the master cylinder...

Actually, they very frequently do leak externally. The problem is, you never see it becouse it leaks into the brake booster, or if you have manual brakes, it leaks down the inside of the firewall pooling up under the carpet/mat. When it leaks past the piston, it has to go somewhere.
The real bummer is, the brake fluid in the booster ends up killing the rubber inside causing the booster to fail. Or, again, if not equipped with a booster, the fluid on the floorboard eats the paint and causes rust.

[Old Yeller 1970]

Good point. In fact I've had that happen before and ruin the brake booster.

[Longhorn Man]

I lost a real strong cad 425 big block to a booster popping from that. I have no booster on there now, and won't untill I have the funds for a NEW booster.

[profe56]

Thanks

[profe56]

Well: I've been checking prices for the master cylinder and now I have a new question before buy it.
I did upgrade drums to disc brakes (swap from 73-87) my truck already has booster and proportioning valve.
Looking on autozone and Kragen, there are two different MC one for drums and one for disc brake system, for sure I have to buy the last one. But I'd like to know which type is in my truck, and I show you a picture.
thanks
[IMG=http://img52.imageshack.us/img52/3807/p4190001s.jpg][/IMG]

Uploaded with ImageShack.us

[Longhorn Man]

if you swapped out the brake system, did you swap out the master cylinder and the prop valve, or did you leave the drum parts there?

[profe56]

To be honest I kept the same MC, PV and Booster was working with the drums system, which are in the picture.Thank you for help me to make the proper fix.
For the question you do I guess I have to change both MC and PV.

[Longhorn Man]

You should swap out to the right parts. The line pressure for a disk brake needs to be much higher than a drum brake. Plus, the valve on a drum/drum system is just a distrabution valve, on a disk/drum set up, it's a distrabution valve.
If your brakes worked good before, setting it up properly will make them work much better.

[Willys47]

Originally Posted by Longhorn Man

You should swap out to the right parts. The line pressure for a disk brake needs to be much higher than a drum brake. Plus, the valve on a drum/drum system is just a distrabution valve, on a disk/drum set up, it's a distrabution valve.
If your brakes worked good before, setting it up properly will make them work much better.

Is a distrabution valve ok to use when doing a disc front and rear convertion?

[profe56]

I just bougth the MC yesterday and I notice the front space for the liquid brake is bigger than back one I'll show you a picture later cause I'm on the way to work
Thanks.