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]

So after much trouble shooting and question asking. I deceided to remove the booster and what a piece of SH**T it was. What a hack mickey mouse looking job someone did. Found out that the booster is off a 80s s10. The bolts did not line up so they drilled the firewall. The front puch rod was to short by about 1 1/2 so it was just sitting there. The rear booster seal was blown and worst off the round center booster housing was beat to death in order for it to fit the firewall hole. I went to autozone (parts store in cali) and to no suprise they where lost. It seemed like I was talking to them in tongue. So I decided to call up my freinds at ABS and POWER STEERING...right away they told me what year,model and booster I had and what was wrong with it. They gave me a new unit with the longer rod...and the right mounting bracket for under $180. I plan on installing the new unit today so I will keep you guys posted.

[jserrato714]

So I just finished installing the new booster and master cylinder...wow what a difference the right parts make. This thing stops on a dime. I had to drill 2 new holes for the new mounting bracket but all in all it was fairly easy with some help. No more of that hissing noise coming from under the dash. The calipers are not sticking no more..It seemed to also help my body role that I posted on earlier in the week. Thanks to all for you replies. Here are some pics of the finished product.

[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.

[fleetsidelarry]

yes, that fixed my problem.
-the instructions for my kit from Master Power Brakes (MPB) also called for drilling the hole 1" lower. when done this way the rod IS at a slight angle. again, it's been this way for years (like, 20 maybe )
-my booster/master cylinder are level like yours
-as I understand the discussion in the MPB booklet, if you leave the rod in the upper hole your brakes may be too "sensitive" (pedal ratio too high) IF your original system was manual not power, which I'm assuming is the case

-the pedal ratio is: the distance from the pedal to the hole divided by the distance from the upper pivot point to the hole
-this means the original hole gives a ratio that is higher than the new (lower) hole

sensitivity seems to be the only issue here that I can find, so you could try it both ways (making necessary adjustment to rod length of course) to see which you prefer.

[jserrato714]

Yeah my brakes are super sensitive on the manual brakes hole..I will use the new hole and add some washers in between my master and booster to add some wiggle room for the pin in between.. Will update thread with hopefully some good news.. Thanks for the help brother.

[jserrato714]

Went ahead yesterday and proceeded to tackle the issue at hand..I started off from scratch. Detached the master from the booster so that I could remove the booster from the firewall and measure my pedal rod length. As soon as the master cylinder was loosened my wheels could be spinned freely...Went ahead and measured the pedal rod from the firewall mounting bracket to the center of the pedal rod eye bolt..I was off by a 1/4 inch to long compared to my stock setup. I went ahead a drilled a new hole on my pedal from the center of the manual stock hole to the center of the new power brake hole which was a bit over an inch center to center.. Reinstalled all the components and sure enough it seemed to fix my problem...bleed the system following the old school two man job...Took most of the old fluid out so that it was nice and clean looking....Went for a drive and it brakes pretty good however it seemed like the pedal would need some force to brake.. so I went ahead and went back to the old stock manual hole for more sensetivy...It helped the problem..Made it easier to stop however Pedal seems to lag a bit in response and not to my liking. I have not checked or adjusted the rear drum brakes...I bleed them at first when I installed the new components and called it a day.. I am looking for that quick brake response sorta like a new car... so no more brake drag just like slow on the pedal response..What do you guys think might be the issue? Air in the lines or rear brake shoes? Feedback welcomed.. Thanks