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Brakes - Help! #1283576 08/11/12 03:26 PM 08/11/12 03:26 PM
Joined: Oct 2004 Posts: 92 Wisconsin 7 70hemi4spdbee OP member
70hemi4spdbee OP member 7 Joined: Oct 2004 Posts: 92 Wisconsin	Front disc brakes won't fully release. 70 Roadrunner originaly a drum drum car. Now front disc, drum rear. Front disc brakes will not fully release. I can turn the tire but they are definitely dragging. New Hemi MC (The Ram Man) and booster. All lines are new to include an Inline brand brake block with disc brake provision. Changed calipers and have same result. Front rubber lines are new as well...everything is new with the exception of pedals. Rear brakes do not drag......only the fronts. Excessive brake dust on front brakes as well which tells me they have been dragging for a while.

Re: Brakes - Help! [Re: 70hemi4spdbee] #1283577 08/11/12 03:31 PM 08/11/12 03:31 PM
Joined: Feb 2010 Posts: 1,377 Ohio Todd pro stock
Todd pro stock Joined: Feb 2010 Posts: 1,377 Ohio	Unbolt the master cylinder from the booster. See if that releases the brakes. Push rod coming out of the booster maybe to long.

Re: Brakes - Help! [Re: 70hemi4spdbee] #1283578 08/11/12 03:33 PM 08/11/12 03:33 PM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	Early design brake calipers always drag slightly, thats why allot of drag racers use drum brakes.. By the term "I can turn it by hand" do you mean with one hand or do you need to grab it with two hands & muscle it some? If you give it a good spin will it spin more than one turn or stop as soon as you stop applying force? Modern design calipers have seals designed to slightly retract the piston which helps fuel mileage, early ones don't.... "The Armies of our ancestors were lucky, in that they were not trailed by a second army of pencil pushers."

Re: Brakes - Help! [Re: 1_WILD_RT] #1283579 08/11/12 04:01 PM 08/11/12 04:01 PM
Joined: Oct 2004 Posts: 92 Wisconsin 7 70hemi4spdbee OP member
70hemi4spdbee OP member 7 Joined: Oct 2004 Posts: 92 Wisconsin	OK...unbolted the master cylinder from the brake booster. Still dragging. I checked under the dash and I see no rod as with drum brake cars. Probably becuase if have the Hemi booster. After setting for a few minutes I can turn the tire by hand but just, if I stop turning it stops immediately. When I drive the car and come to a stop light the car will not roll. You can feel the front discs are dragging. That coupled with a tremendous amount of brake dust tells me something is wrong. I checked the steel wheels to see if they were hot but were not any warmer than the rear wheels. Perplexing.... I do not want to go on a long haul and have a fire....bad juju.

Re: Brakes - Help! [Re: 70hemi4spdbee] #1283580 08/11/12 04:34 PM 08/11/12 04:34 PM
Joined: Dec 2007 Posts: 18,157 Mass DAYCLONA I Live Here
DAYCLONA I Live Here Joined: Dec 2007 Posts: 18,157 Mass	Quote: All lines are new to include an Inline brand brake block with disc brake provision. OK you eliminated the first conclusion that perhaps the pushrod from the booster, which is ajustable, was not over adjusted/misadjusted causing a possible residual pressure problem in the front calipers, by unbolting the master from the booster... next is that junk IN-LINE manufactured proportioning valve, they have had a bad run of repros, has been discussed many times here by those that had issues with them, replace it with a FINE-LINES manfactured proportioning valve, you may see the same PN@ on fine-lines website as the IN-LINE PN#...both companies at one time had the same vendor, hence the same number, FINE-LINES has pulled all their old stock and replaced it with another vendor to eliminate customer hassles like what your experiencing, IN-LINE however continues to sell their junk PV's Wayne (RAMMAN) puts out a great product, but if he's supplying IN-LINE PV's as part of his systems, he doing himself a disservice supplying them... Mike

Re: Brakes - Help! [Re: DAYCLONA] #1283581 08/11/12 04:41 PM 08/11/12 04:41 PM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	"The Armies of our ancestors were lucky, in that they were not trailed by a second army of pencil pushers."

Re: Brakes - Help! [Re: 1_WILD_RT] #1283582 08/11/12 06:52 PM 08/11/12 06:52 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	crack a caliper bleeder valve to release the pressure & jack it up & bearhug the wheels again which'll tell you if it's a psi problem (as said prop valve) or the calipers/adapters themselves. I had one that seemed to hard to turn (A body BBP discs) & I replaced the caliper with a cheap reman & it turned alot easier, not free by any means which wont happen but easier enough that I was comfortable with it. There is not supposed to be a RPV in the disc half of a M/C but wouldn't hurt to check by sticking a drill bit deep into the brass cone in the disc half & you'll feel the springy RPV if the assembly line people made a mistake & installed one live every 24 hour block of time like it's your last day on earth

Re: Brakes - Help! [Re: RapidRobert] #1283583 08/12/12 07:48 AM 08/12/12 07:48 AM
Joined: Oct 2004 Posts: 92 Wisconsin 7 70hemi4spdbee OP member
70hemi4spdbee OP member 7 Joined: Oct 2004 Posts: 92 Wisconsin	Just to be sure I checked my work. Unbolted the master cylinder from the booster and the brakes released somewhat. Before I start removing the brake block I want to eliminate a too long pushrod. I looked under the dash and see no pushrod? This car has the Hemi brake booster with the levers. Where is the adjustment? Not under the dash obviously.....in the engine bay behind the booster perhaps? The RAM MAN did not provide the brake block, only the booster which seems to be a very good unit. I purchased the brake block seperately from Inline Tube about three years ago. When I purchased the brake block it was a complete unit with the prop valve attached to the same mounting arm. Not sure if this is the correct unit. Seems I have seen other B bodies with the rear prop valve, or maybe it is a rear bias valve, bolted to the frame under the car downstream from the block? Do I have an incorrect brake block for a 70 B body? Is the prop valve and the bias valve two seperate issues here?

Re: Brakes - Help! [Re: 70hemi4spdbee] #1283584 08/12/12 09:00 AM 08/12/12 09:00 AM
Joined: Feb 2009 Posts: 1,274 Ontario.Canada C can.al pro stock
can.al pro stock C Joined: Feb 2009 Posts: 1,274 Ontario.Canada	..sounds like there could be a residual pressure valve in the master. just a thought.

Re: Brakes - Help! [Re: can.al] #1283585 08/12/12 09:19 AM 08/12/12 09:19 AM
Joined: Jan 2007 Posts: 7,664 IN A ahy master
ahy master A Joined: Jan 2007 Posts: 7,664 IN	Quote: ..sounds like there could be a residual pressure valve in the master. just a thought. Agree... as suggested above next diagnostic is to crack a bleeder and see if that releases some of the drag. If so there is a residual pressure valve in the master or in the distribution block or one of the above is malfunctioning. Also, there is a possibility the flex hoses are collapsed inside... they will expand to apply brakes but close up afterwards and retain pressure. I had this on a DD Neon and changed hoses based on a tip from MOPARTs. It cleared right up. The hoses were old.

Re: Brakes - Help! [Re: 70hemi4spdbee] #1283586 08/12/12 10:28 AM 08/12/12 10:28 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: Unbolted the master cylinder from the booster and the brakes released somewhat. where is the adjustment? I think we found the problem. Unbolt the M/C from the booster & pull it forward a bit & you'll see the threaded rod with the round nub on the end. Measure the depth of the recess in the M/C piston and measure how far out the rod protrudes from the booster & adj the rod so there is ~1/16" clearance between the rounded nub and the bottom of the piston recess. live every 24 hour block of time like it's your last day on earth

Re: Brakes - Help! [Re: RapidRobert] #1283587 08/12/12 07:30 PM 08/12/12 07:30 PM
Joined: Oct 2004 Posts: 92 Wisconsin 7 70hemi4spdbee OP member
70hemi4spdbee OP member 7 Joined: Oct 2004 Posts: 92 Wisconsin	Rapid Robert, You were right, drove the car and the brakes dragged. Brought it right in an unbolted the MC and pulled it away from the booster. The brakes released. The rod appears to be sticking out of the booster at least an inch and a half. How do you adjust the rod? Does it just screw in? At this point I have found the problem thanks to you folks...now to fix it.

Re: Brakes - Help! [Re: 70hemi4spdbee] #1283588 08/12/12 07:56 PM 08/12/12 07:56 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Todd nailed her 1st. Yes it's right hand threads & should have a little locknut on the threads live every 24 hour block of time like it's your last day on earth

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