Front discs won’t release

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Scotty D

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Convoy, Ohio
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Scott
Truck Year
1979
Truck Model
C10 Bonanza Big10
Engine Size
305
Need some help, I went through my brakes a couple of years ago- new master cylinder, calipers, pads, rotors, hoses, proportioning valve. Everything was working great, went to drive it the other day and it didn’t seem to roll like normal (I don’t drive it much as I like)
Found both front brakes hot and locked up after a 5 mile drive.
I cracked the lines on the master (thinking it was stuck but no pressure coming back to the master)
I can’t believe that both calipers are bad, or both hoses are collapsing after about 4 years time
Any ideas?
 

Edelbrock

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Earth
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Grumba
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1977
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K5 Blazer
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400
Need some help, I went through my brakes a couple of years ago- new master cylinder, calipers, pads, rotors, hoses, proportioning valve. Everything was working great, went to drive it the other day and it didn’t seem to roll like normal (I don’t drive it much as I like)
Found both front brakes hot and locked up after a 5 mile drive.
I cracked the lines on the master (thinking it was stuck but no pressure coming back to the master)
I can’t believe that both calipers are bad, or both hoses are collapsing after about 4 years time
Any ideas?

Try lubing the caliper pins. Get them locked up again and try cracking open the bleeders on the calipers to see if they release.
 

Scotty D

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Convoy, Ohio
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Scott
Truck Year
1979
Truck Model
C10 Bonanza Big10
Engine Size
305
I finally got my brake problem solved- the proportioning valve was stuck and would not reset.
Replaced it and good as new, tore the old one apart and found it full of corrosion. Not sure why, was all new fluid when I replaced the valve, calipers, hoses and wheel cylinders a couple years ago.
 

Edelbrock

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Grumba
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1977
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K5 Blazer
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400
I finally got my brake problem solved- the proportioning valve was stuck and would not reset.
Replaced it and good as new, tore the old one apart and found it full of corrosion. Not sure why, was all new fluid when I replaced the valve, calipers, hoses and wheel cylinders a couple years ago.


Thanks for the update. We have been wondering what the outcome was.
 

hey mister

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Marty
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1978
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C10
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350
I was getting ready to write P valve.
I seen an episode on Road Kill and the valve was bad.

Glad you found it.
 

fast 99

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Amazes me how many proportioning valve are replaced on this forum. Obviously this vehicle needed a replacement. Bet in my entire life as a tech, replaced less than 5. These vehicles getting older might explain it.
 

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