74 C10 front left disc locked

[fast 99]

Fluid comes out and piston travels back. So i was said

Do the brakes unlock that was the question

Reason answering this in important, brakes can still be locked if there is a mechanical caliper issue. Piston traveling back doesn't tell us much other than it moved. I am trying to help not being an as*.

 

[Ricko1966]

OKay so th

Fluid comes out and piston travels back. So i was told

Is just got easy now crack the same line at the combination valve see if fluid squirts and piston releases. If so crack the line on the other side. The last connection that it traps fluid is where the problem is.

 

[elbpony]

OKay so th

Is just got easy now crackntge same line at the combination valve see if fluid squirts and piston releases. If so crack the line on the other side. The last connection that it traps fluid is where the problem is.

Can you explain that to me on another way?

 

[Ricko1966]

Fluid is getting trapped holding the piston out. If you crack the bleeder and fluid pressure releases and the piston releases,we know it has trapped fluid. Now crack the steel line at rubber hose does pressure release and the piston release,if so we know the fluid is trapped further back. Go to your next connection point,does fluid release? Keep going,your going to get to a point that fluid no longer releases,that's where you are trapping the fluid.Lets say you crack the steel line at the rubber hose and fluid releases,then next you crack the same line at the other end but that doesn't relieve pressure well then that line has an internal blockage,pinched etc. You do have to step on the pedal and stick the caliper at each point in this.

 

[elbpony]

Fluid is getting trapped holding the piston out. If you crack the bleeder and fluid pressure releases and the piston releases,we know it has trapped fluid. Now crack the steel line at rubber hose does pressure release and the piston release,if so we know the fluid is trapped further back. Go to your next connection point,does fluid release? Keep going,your going to get to a point that fluid no longer releases,that's where you are trapping the fluid.Lets say you crack the steel line at the rubber hose and fluid releases,then next you crack the same line at the other end but that doesn't relieve pressure well then that line has an internal blockage,pinched etc. You do have to step on the pedal and stick the caliper at each point in this.

Got that. Thanks

 

[xm20k]

Something I just thought of. I bought some premade lines that had these rubber plugs in the ends to keep stuff out of them while in storage I assume If they were overlooked the line would screw in as they are smaller than the threaded part of the fittings.
Found one still laying on the work bench.

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[BryanC]

On my '73 one-ton, the passenger front disc locked even though I had previously had a shop replace the front calipers, flexible brake hoses, and flush the brakes. IIRC, the proportioning valve has three output ports, one for each front wheel and one port to the rear drums. The brake shop recommended rebuilding the proportioning valve, which cleared up the problem. However, when they went to re-install the proportioning valve, the 50+ YO lines started to split, so I ended up replacing the metal brake lines at the same time.

 

[elbpony]

hi y´all

finally I have my truck with me, now. The shop got it done, it was, not as anyone ever mentioned it, the rubber hose. I take a bow.

Thanks to your persistence and numerous claim that it must be the rubber hose, I could make the shop having a further look into them and that changed the game. New hoses, no more problems. Besides the MC is changed as well, now. The old one looked pretty rusted and closer to death than to live.

Now, thanks to you all for being patient and helpful. I appreciate it.
Tim

 

[elbpony]

Something I just thought of. I bought some premade lines that had these rubber plugs in the ends to keep stuff out of them while in storage I assume If they were overlooked the line would screw in as they are smaller than the threaded part of the fittings.
Found one still laying on the work bench.

You must be registered for see images attach

uhhh. now that is tricky but very realistic situation...

 

[DRW65]

I have seen a brand new caliper hose be bad and deal me misery.

 

[Andronikos]

the calipers are connected to steel lines.

So the calipers are connected to a braided steel flexible line? They can not be connected with a rigid line. Open the bleeder screw on the caliper. If that releases the caliper, take the flexible line off and inspect it with low pressure compressed air. It should flow free in each direction.

 

[Ricko1966]

So the calipers are connected to a braided steel flexible line? They can not be connected with a rigid line. Open the bleeder screw on the caliper. If that releases the caliper, take the flexible line off and inspect it with low pressure compressed air. It should flow free in each direction.

This has all been covered and the vehicle is already fixed.

 

[elbpony]

thanks for considering though. I will surely come up with other topics that can need your help. Appreciate it

 

[Snoots]

thanks for considering though. I will surely come up with other topics that can need your help. Appreciate it

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[gympsy]

I had a similar issue once and it turned out to be the brake hose collapsing internally. Even if it looks new, I’d swap it out before digging deeper into the master.

Tutuapp​