rear brakes locking up - The 1947 - Present Chevrolet & GMC Truck Message Board Network

derail · 05-03-2006, 04:38 PM

I am having a problem with the rear brakes locking up on my '65. I have the e.c.e front disc conversion with spindles,booster,and everything else. The rears are drums from a '72? for 5 lug wheels. Everything on the front and back is brand new including drums, cylinders, etc. The problem is.... when I first bled them (after I bench bled the m/c) I could not get brake fluid to come out of the rears. When I disconnected the brake lines from the rear, there was fluid to the cylinders. So I hooked them all back up and drove it like that for a little while. The brakes were o.k. but not like I would have expected for the upgrades. So, last weekend I had my daughter help me bleed them again. This time, the rears had fluid coming out of the bleeder valves, but the pedal would only go about half-way to the floor. The fronts bled fine. Now if you even barely tap the brakes going down the road, the rears are locking up. I called e.c.e and we have determined that it is not because the piston in the prop. valve is stuck one way or another. I am going to re-bleed them this weekend when I get some help, but in the meantime, any suggestions? Thanks. -Justin

welsh kev · 05-03-2006, 05:04 PM

Try 5 bags of cement in the bed!

Chevrolet4x4s · 05-03-2006, 05:56 PM

Check and see if the breke adjusters are ran out too far try letting them off a little bit.
Hope this helps.
Shane

Frizzle Fry · 05-03-2006, 06:17 PM

Quote:

Originally Posted by derail

I am having a problem with the rear brakes locking up on my '65. I have the e.c.e front disc conversion with spindles,booster,and everything else. The rears are drums from a '72? for 5 lug wheels. Everything on the front and back is brand new including drums, cylinders, etc. The problem is.... when I first bled them (after I bench bled the m/c) I could not get brake fluid to come out of the rears. When I disconnected the brake lines from the rear, there was fluid to the cylinders. So I hooked them all back up and drove it like that for a little while. The brakes were o.k. but not like I would have expected for the upgrades. So, last weekend I had my daughter help me bleed them again. This time, the rears had fluid coming out of the bleeder valves, but the pedal would only go about half-way to the floor. The fronts bled fine. Now if you even barely tap the brakes going down the road, the rears are locking up. I called e.c.e and we have determined that it is not because the piston in the prop. valve is stuck one way or another. I am going to re-bleed them this weekend when I get some help, but in the meantime, any suggestions? Thanks. -Justin

May be a dumb question, but is there any way that you may have swapped front/rear channels? I've seen that happen before (don't ask

) and it acted like your description.

dwcsr · 05-03-2006, 06:35 PM

Like fred says it does happen. Also check that the master is for disc front rear drum and that you have a functioing proportioning valve for Disc/Drum setup. The large reservior is for the disc side.

derail · 05-04-2006, 02:12 AM

Thank you guys for the replies. I will check and double check everything. I'll try everything suggested except the 5 bags of cement.

I'll let you know how it turns out.

05-03-2006, 04:38 PM	#1
derail Registered User Join Date: Sep 2005 Location: redding,ca. Posts: 182	rear brakes locking up I am having a problem with the rear brakes locking up on my '65. I have the e.c.e front disc conversion with spindles,booster,and everything else. The rears are drums from a '72? for 5 lug wheels. Everything on the front and back is brand new including drums, cylinders, etc. The problem is.... when I first bled them (after I bench bled the m/c) I could not get brake fluid to come out of the rears. When I disconnected the brake lines from the rear, there was fluid to the cylinders. So I hooked them all back up and drove it like that for a little while. The brakes were o.k. but not like I would have expected for the upgrades. So, last weekend I had my daughter help me bleed them again. This time, the rears had fluid coming out of the bleeder valves, but the pedal would only go about half-way to the floor. The fronts bled fine. Now if you even barely tap the brakes going down the road, the rears are locking up. I called e.c.e and we have determined that it is not because the piston in the prop. valve is stuck one way or another. I am going to re-bleed them this weekend when I get some help, but in the meantime, any suggestions? Thanks. -Justin

05-03-2006, 05:04 PM	#2
welsh kev Registered User Join Date: Apr 2004 Location: Carmarthen, Wales, UK Posts: 102	Re: rear brakes locking up Try 5 bags of cement in the bed! __________________ 63 GMC fleetside, 305 V6; over-built, over thirsty and over here!

05-03-2006, 05:56 PM	#3
Chevrolet4x4s Registered User Join Date: Nov 2005 Location: WV Posts: 227	Re: rear brakes locking up Check and see if the breke adjusters are ran out too far try letting them off a little bit. Hope this helps. Shane __________________ 1993 K1500 350 5 speed 1985 K10 Silverado Vortec 406 5 speed (in body shop) "I been drivin' this '85 pickup truck Them buddies of mine call it a bucket of rust She's a little beat up but she still runs like the wind Yeah, kinda like me I been banged and bruisedBeen around the block a time or two But I'm runnin' like new goin' places I never been No, I ain't broke I'm just broken in" 1963 Dodge Townwagon(its amazng what 30 years and zero miles will do to a vehicle ) Member#20327

05-03-2006, 06:35 PM	#5
dwcsr Hollister Road Co. Join Date: Apr 2005 Location: Houston Posts: 6,131	Re: rear brakes locking up Like fred says it does happen. Also check that the master is for disc front rear drum and that you have a functioing proportioning valve for Disc/Drum setup. The large reservior is for the disc side.

05-04-2006, 02:12 AM	#6
derail Registered User Join Date: Sep 2005 Location: redding,ca. Posts: 182	Re: rear brakes locking up Thank you guys for the replies. I will check and double check everything. I'll try everything suggested except the 5 bags of cement. I'll let you know how it turns out.



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