Brake caliper help... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

FRENCHBLUE72 · 07-13-2008, 11:25 AM

My passenger side brake caliper is locked up. I can push it back with some force and itll free up the wheel but as soon as I hit the brakes agian its locked up and wont retract. My question is, the caliper bad or do I seem to have yet another problem? The truck was drums all around and the previous owner converted the front to disk,still had the stock master cylinder also.. Any help would be great..

DREAMS OF A 67 · 07-13-2008, 11:36 AM

the master cylinder and proportioning valve are different for disc than they are for drums. If they have already been changed in the conversion , you most likely have a bad caliper.

dwcsr · 07-13-2008, 11:49 AM

I think that if it were the master both would drag and/or lock.

The 2 possiblilties are bad caliper or a bad hose. I had a 92 with a bad hose that colapsed inside and when it got hot is wouldn't let the fluid back out. The master should also be changed to a disc/drum master along with the Prop valve.

FRENCHBLUE72 · 07-13-2008, 12:16 PM

The drivers side rotates fine so i guess I geta new caliper and hose and be on the look out for a new master cylinder/prop combo... Thanks Guys..

cdowns · 07-13-2008, 01:14 PM

i second the hose theory/have had it happen to me

BLACK AND BLUE 67-72 · 07-13-2008, 01:19 PM

Yep, sounds like a bad caliper or hose.

**steelhorse** · 07-13-2008, 02:20 PM

Pop the bleeder loose and if it frees up its the hose if not its the caliper.If the hoses are cracked or old it wouldnt be a bad idea to replace anyway

Lugnut64052 · 07-13-2008, 02:33 PM

If you replace the caliper, put a hose on it too.

Like dwcsr said, sometimes the hose will collapse internally. You can force fluid through it when you hit the brakes, but it won't allow the caliper to relax back.

RoadRacer · 07-13-2008, 06:49 PM

It's possible that the brake fluid has water in it as well, which may have created rust inside the piston bore. The hydraulic pressure can force the piston out, but it won't release because of the rusted bore.

If you replace the caliper be sure to flush the brake fluid completely to make sure there's no chance of a repeat occurrence.

**truckdude239** · 07-13-2008, 08:53 PM

i say hose had an 89 gmc do the same thing pop ythe blleeder screw and see if the pistion will go in easy

FRENCHBLUE72 · 07-13-2008, 11:39 PM

Welll guys it look s like it was the caliper I replaced both hoses and still get the same thing,so it looks like imma replace the calipers next..

chip46wis · 07-14-2008, 07:12 AM

I just bought NEW calipers from one of the big chain auto stores for $11.97 each,hoses were $18 a piece,replace them and drive with the piece of mind.

70rs/ss · 07-15-2008, 04:44 PM

Could be the sliders are gunked up as well? Do new ones and be sure to add the lude to the slides and all will be good, and I 5 th the hose part as I had a Chevelle do that to me, pushed the peddle then the right front was locked up!

07-13-2008, 11:25 AM	#1
FRENCHBLUE72 PROJECT 7DEUCE Join Date: Dec 2002 Location: GRANTS PASS OR Posts: 21,606	Brake caliper help... My passenger side brake caliper is locked up. I can push it back with some force and itll free up the wheel but as soon as I hit the brakes agian its locked up and wont retract. My question is, the caliper bad or do I seem to have yet another problem? The truck was drums all around and the previous owner converted the front to disk,still had the stock master cylinder also.. Any help would be great.. __________________ GO BIG GREEN GO DUCKS MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P..

07-13-2008, 11:36 AM	#2
DREAMS OF A 67 Step Brother Join Date: Sep 2007 Location: knoxville TN Posts: 1,950	Re: Brake caliper help... the master cylinder and proportioning valve are different for disc than they are for drums. If they have already been changed in the conversion , you most likely have a bad caliper.

07-13-2008, 11:49 AM	#3
dwcsr Hollister Road Co. Join Date: Apr 2005 Location: Houston Posts: 6,131	Re: Brake caliper help... I think that if it were the master both would drag and/or lock. The 2 possiblilties are bad caliper or a bad hose. I had a 92 with a bad hose that colapsed inside and when it got hot is wouldn't let the fluid back out. The master should also be changed to a disc/drum master along with the Prop valve.

07-13-2008, 12:16 PM	#4
FRENCHBLUE72 PROJECT 7DEUCE Join Date: Dec 2002 Location: GRANTS PASS OR Posts: 21,606	Re: Brake caliper help... The drivers side rotates fine so i guess I geta new caliper and hose and be on the look out for a new master cylinder/prop combo... Thanks Guys.. __________________ GO BIG GREEN GO DUCKS MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P..

07-13-2008, 01:14 PM	#5
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Brake caliper help... i second the hose theory/have had it happen to me __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

07-13-2008, 01:19 PM	#6
BLACK AND BLUE 67-72 Firefighter Join Date: Feb 2001 Location: Yellville, Ar, USA Posts: 1,943	Re: Brake caliper help... Yep, sounds like a bad caliper or hose. __________________ '72 Chevy SWB 350 Auto '67 GMC LWB 350 4 speed '70 Chevy 4x4 Stepside 350 Auto Yellville, Ar. USA

07-13-2008, 02:20 PM	#7
steelhorse Senior Member Join Date: Apr 2008 Location: Franklinton NC Posts: 1,309	Re: Brake caliper help... Pop the bleeder loose and if it frees up its the hose if not its the caliper.If the hoses are cracked or old it wouldnt be a bad idea to replace anyway

07-13-2008, 02:33 PM	#8
Lugnut64052 Middle-aged Curmudgeon Join Date: Jun 2008 Location: Independence, MO Posts: 753	Re: Brake caliper help... If you replace the caliper, put a hose on it too. Like dwcsr said, sometimes the hose will collapse internally. You can force fluid through it when you hit the brakes, but it won't allow the caliper to relax back.

07-13-2008, 06:49 PM	#9
RoadRacer Tire Shredder Extraordinaire Join Date: Dec 2006 Location: Upland, CA Posts: 62	Re: Brake caliper help... It's possible that the brake fluid has water in it as well, which may have created rust inside the piston bore. The hydraulic pressure can force the piston out, but it won't release because of the rusted bore. If you replace the caliper be sure to flush the brake fluid completely to make sure there's no chance of a repeat occurrence.

07-13-2008, 08:53 PM	#10
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,238	Re: Brake caliper help... i say hose had an 89 gmc do the same thing pop ythe blleeder screw and see if the pistion will go in easy __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

07-13-2008, 11:39 PM	#11
FRENCHBLUE72 PROJECT 7DEUCE Join Date: Dec 2002 Location: GRANTS PASS OR Posts: 21,606	Re: Brake caliper help... Welll guys it look s like it was the caliper I replaced both hoses and still get the same thing,so it looks like imma replace the calipers next.. __________________ GO BIG GREEN GO DUCKS MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P..

07-14-2008, 07:12 AM	#12
chip46wis Registered User Join Date: Dec 2004 Location: Central Wisconsin Posts: 1,317	Re: Brake caliper help... I just bought NEW calipers from one of the big chain auto stores for $11.97 each,hoses were $18 a piece,replace them and drive with the piece of mind.

07-15-2008, 04:44 PM	#13
70rs/ss Registered User Join Date: Dec 2004 Location: Northern AZ Posts: 7,270	Re: Brake caliper help... Could be the sliders are gunked up as well? Do new ones and be sure to add the lude to the slides and all will be good, and I 5 th the hose part as I had a Chevelle do that to me, pushed the peddle then the right front was locked up!



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