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Old 04-20-2013, 06:49 PM   #1
Cris.sanchez3
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Need brake help!!

I recently did my front disk convertion, was my first but it was kinda simple common sense kinda job everything went on good so I drop it and bleed the brakes so far so good but did a little brake trial down my driveway and the truck wouldn't move I had to give it a lot of gas , when I got out I saw tore track I'm guessing one of the brakes is locked up I'm going to take it apart and inspect everything again but just wanted to see if anyone had any thought on what it might be any suggestions would be helpful, my guess the line is clogged and brake not releasing. Thanks in advance!!
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Old 04-20-2013, 07:04 PM   #2
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Re: Need brake help!!

Jack it up and put it on stands. See if the tires spin by hand. If they all spin freely it might be a bad swollen hose. You did install new hoses right? If either wheel won't turn try pulling the wheel of and again check for rotation. Old wheels may not clear brake calipers. Did you change to a disc master cylinder and replace the distribution valve with a proportioning valve?
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Old 04-20-2013, 07:38 PM   #3
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Re: Need brake help!!

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Jack it up and put it on stands. See if the tires spin by hand. If they all spin freely it might be a bad swollen hose. You did install new hoses right? If either wheel won't turn try pulling the wheel of and again check for rotation. Old wheels may not clear brake calipers. Did you change to a disc master cylinder and replace the distribution valve with a proportioning valve?

Yeah I did change the hoses it came the kit and the master cylinder was changed but km holding of with the proportioning valve, I'm sure the calipers fit it was spinning fine with the tire when I had it up. Well ima try an see if I have time to look at it tomorrow
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Old 04-20-2013, 08:15 PM   #4
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Re: Need brake help!!

OK we need to be clear on this.
You used a kit.
What kit was it?
You replaced the two front hoses.
You replaced the master cylinder.
You have not replaced the distribution block with a proportioning valve.
Was the new master cylinder as drum/drum or a disc/drum?
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Old 04-20-2013, 08:34 PM   #5
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Re: Need brake help!!

Yeah it was a disk convertion kit I got on eBay with drop spindles it came with spindles, rotors, calipers, pads,rubber hoses, I just went to autozone and got the disk/drum master cylinder. I was gonna see how much of a difference it was between front and back before buying the proportioning valve. The thing is when I bleed the brakes brake fluid came out fine from the bleed valves but ima see if maybe someway that one got clogged or something!by the way I appreciate the help
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Old 04-20-2013, 08:50 PM   #6
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Re: Need brake help!!

Are you sure it is a disc/drum M/C? If you told Autozoned the year of your truck....
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Old 04-20-2013, 08:51 PM   #7
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Re: Need brake help!!

Yeah made sure they knew disk/drum and compared
It to the drum/drum that was in there
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Old 04-20-2013, 09:27 PM   #8
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Re: Need brake help!!

You need the new prop valve also. Reason is the disc requires less pressure to activate than drum it locks up ur front brakes because now it is getting too much fluid and not releasing your front calipers after stepping on the brake... That is my guess..
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Old 04-20-2013, 09:42 PM   #9
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Re: Need brake help!!

That could be but the calipers should release after letting go since the pressure has been released
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Old 04-20-2013, 09:57 PM   #10
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Re: Need brake help!!

Another thing posted before is some Master cylinders are setup to run the front disks on the rear master side n some on the front side. Depending on which manufacture master you are using. Someone posted pics before where some of the 3/4 T were plumbed that way. Look into that also. Possibly the one you have got put into the wrong box?? Suppose you could tell that by looking down inside the master as to the size of the orfice. ?? The side for disk would be smaller diameter?? Just throwing some stuff out there for you.
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Old 04-20-2013, 10:18 PM   #11
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Re: Need brake help!!

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You need the new prop valve also. Reason is the disc requires less pressure to activate than drum it locks up ur front brakes because now it is getting too much fluid and not releasing your front calipers after stepping on the brake... That is my guess..
Well he knows he needs one just has not admitted it to himself yet.

Your description is unfortunately completely backwards. Disc brakes require more fluid and pressure to operate that is why there were few unboosted truck disc applications. The drums need less pressure and fluid so using a prop valve prevents them from locking first thats no fun. It reduces the pressure to the rears allowing the fronts to "catch up" and be the primary braking initiator.

For some reason it sounds like there is a residual pressure valve holding the brakes "on" if there is not a mechanical issue preventing caliper retraction. Pretty sure the factory residual pressure valves were in the M/C only IIRC. Once you have verifed operating clearance for the wheels I'd look at trying to retract the calipers a little and see if they move. If you can't crack the bleeder and see if that releases it. Then close it back and cycle the brakes. If there is a residual pressure valve or a hose pretending to be one you can find it this way.

Are you sure you have a C10 M/C as C20s have reversed outlets.
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Old 04-21-2013, 12:00 AM   #12
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Re: Need brake help!!

Yup It's a c10 I checked it, we'll thanks guys ill let you know tomorrow what I find out ima open the bleeder valve and see if it retracts
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Old 04-21-2013, 09:48 AM   #13
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Re: Need brake help!!

SS Tim, I stand corrected as you point out. I knew there was a vast difference between the drum side and the disc side. My brain knew that but I mistyped was my brain was telling me. KUDOS.
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Old 04-21-2013, 03:08 PM   #14
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Re: Need brake help!!

Well guys I figured it out and I feel stupid, I never noticed that I had one of my four tires that was different so the caliper hit the rim an that's why I locked up. So my solution is since I have drums in the back I'm just gona switch a back tire with the front.
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Old 04-21-2013, 03:09 PM   #15
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Re: Need brake help!!

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Old 04-21-2013, 03:24 PM   #16
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Re: Need brake help!!

Thanks for reporting back on this. Glad it was something minor and not a rework. You should not have much trouble finding another wheel or two (is the spare useable?). Next time I am in Oxnard I will pick up my gold star. :-)
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Old 04-21-2013, 03:27 PM   #17
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Re: Need brake help!!

Not to worried about tires they look so similar that I dnt even notice so for now their gonna stay and spare is the same siza that doest fit. Oh and your gold star will be waiting you deserve it!!!
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