63 c10 front brakes are stuck

[jserrato714]

Hello peeps, I decided today to finally drive my truck around the city for the first time. To my suprise after 5 minutes of driving, I hit the gas and theres a lack of responce almost like someone was holding the truck back. I pulled in to my driveway and my brakes and rotors where super hot. Hot enough that it bubbled my wheel paint. I had this problem before where the brakes stay stuck and literally dont let go so I replace the brake pads,brake hoses,and the calipers with new ones. I thought I had resolved the problem too I found out today that I was wrong. NOTE: I have power brakes aswell as front disc brakes off a 73 c10 truck. What can It be? I did the booster test ..with the truck off I pumped the breaks until the pedal got hard and then started and the pedal went down like it should with the engine vacuum. What am I missing here?a pinched line some where acting like a valve?can it be the drum breaks in the back? PLEASE HELP....DONT HAVE A CAR TO GO TO WORK.THANKS TO ALL!!

[markeb01]

My first thought was a drum brake master cylinder. Try the following checklist, it might help identify the problem:

http://www.mpbrakes.com/technical-su...sc-drum-04.cfm

I also had this problem years ago on a Chevelle, and it turned out to be a warped caliper bracket. The wheel could barely be turned by hand there was so much drag.

[Sick5]

did you fig it out?

[62 Bowtie]

Do you have a prop valve I'm no expert but I read once they can stick

[Bugeyev8]

check the pushrod on the master cylinder and make sure there is a little free play, sounds like your master cylinder is not returning

[Captainfab]

This is where I'd look first....the pushrod between the booster and the master. What booster, master and prop valve are you running?

Originally Posted by Bugeyev8

check the pushrod on the master cylinder and make sure there is a little free play, sounds like your master cylinder is not returning

[jserrato714]

Ok peeps I just finished for the day on my truck its 11 pm pst.What a day...ok I do have a prop valve...I checked all the lines for kinks and they are all good...checked the prop valve( I dont know how to tell if there bad) I blew air through it and clean it out...I took my master cylinder and checked it because I believed it was not returning all the way back and since its only $14 I went for it..Note: The vehicle is up on jack stands. Before I changed the master with the truck on I would press the brake once and let go, then I would check the tires and they would be completly locked. After I changed the master and bleed the system I did the same procedure as above and the wheels would kinda spin but still some resistance so I decided to check my pedal set up..I found some play where the pedal meets the shaft(rod) coming from the booster. The previous owner added a huge coter pin (aka ***** pin) that fits the hole perfectly but is a bit to long therefore giving me some play. I believe thats my problem and I plan on installing a bolt through the hole with some pressure washers and nut.

[fleetsidelarry]

I had the same problem. I have a power brake booster from Master Power Brakes, they supplied the MC also but its nothing special. The installation instructions state that the geometry of the lever system is different between power and standard, the pushrod travel is different, requiring a new mounting hole to be drilled in the pedal arm 1 inch below the original. Did the PO relocate the point where the rod attaches to the brake pedal arm?

Also, there needs to be some end play (.020 in according to MPB) between the booster rod and the MC. That was where my problem was. Apparently, if the end play isn't there, the system won't release pressure. This would match up with what Bugeyev8 and Captainfab already said.

(note, this is not the rod you were talking about earlier with the cotter pin, it should be ok for that rod to have some free play, your pedal should have 1/4 inch or more of free travel before the system starts to engage)

[jserrato714]

Ok well the free play I am talking about is side to side not forward and backwards from booster to pedal. My wiggles some what freely lets say from fender to fender. If I full the pedal a bit towards the pedal stock grommet the problem seems to go away. I bought the truck this way...I have to guess or match up parts to figure out what years there from. My master was a match off of a 69 c10 305 sbc so I am guessing my booster is the same. Also the rod that comes out of my booster maybe was short and they seemed to extend it.Looks like they made a plate to extend it. Should a stock 69 c10 booster fit(bolt ride up) or does it need modification? Also When I turn on my truck I hear sorta like an air leak. Then I press the brake and it goes away? Any ideas? I want to try that bolt and see if that works? PLEASE HELP ME!!!!ASAP here are some pics of the pedal!

[jserrato714]

Good morning forum....so after using the search bar on my brake drag problem on my current truck. 65 c10 short bed I came across my old post. I am having similiar issues on my 65 c10.
I am using a cpp kit that came up all put together 9" booster with master and disc/drum prop valve. Truck is off the ground on jack stands..wheels are tight and hard to spin..I have adjusted the rod that goes from boster to pedal as close to what it was before on my manual brakes..I have about 1/8 play..however I am using the stock hole on the pedal where the manual brake rod bolted on to...I know that my ratio is off but is this the brake drag cause... I drilled a hole 1" bellow that but my brake rod seems to be at a weird angle at the new hole. When I use the existing manual brakes hole the rod is perfectly straight looking angle wise..
I have not checked the rod pin between the master and booster for length as this was already put together at cpp for a bolt on ready application. I read that they cpp are having issues with sticking prob valves. Can I leave the pedal rod on the old manual brakes hole? I was thinking of unbolting the master from the booster and see if the brakes loosen..if so maybe machine. The rod down or add some washers between master and booster.. Please help ...
Note: rear wheels are not stuck and spin freely ..Problem is only the front disc brakes having drag. I have bleed the system throughout. ..

[fleetsidelarry]

Originally Posted by jserrato714

I have not checked the rod pin between the master and booster for length as this was already put together at cpp for a bolt on ready application. ..

you need to check this. I had the exact same issue when I did my disc brakes although mine wasn't a pre-assembled unit. (see my post #8 above, there has to be some small amount of play otherwise the calipers with not release). it may be fine, but you won't know 'til you check

[jserrato714]

Thanks for the reply Larry..so I should start with the master/booster rod..if so would it be ok to use some washers at the booster/ master mating bolts to extend so that the rod has room to move.

[fleetsidelarry]

Originally Posted by jserrato714

.if so would it be ok to use some washers at the booster/ master mating bolts to extend so that the rod has room to move.

that's actually exactly what I did . I did it to check but was lazy and left the washers in and never actually adjusted the rod. it's been that way for years BUT really I should have done it properly 'cause the washers, of course, leave a gap.

[jserrato714]

Originally Posted by fleetsidelarry

that's actually exactly what I did . I did it to check but was lazy and left the washers in and never actually adjusted the rod. it's been that way for years BUT really I should have done it properly 'cause the washers, of course, leave a gap.

So im assuming this fixed your problem larry...my booster/ master bolted up perfectly straight on the firewall..I know some installs look like they are at a upwards angle but not mine. So when I install the pedal rod on the new hole one inch below. The rod is at an awkward angle...when I switch it to the manual hole its perfectly straight with the booster master. Per Classic Performance they call for that rod to be perfectly straight with the boster/master... Not sure what to do here...feedback welcomed.