C3 Vette Registry - The Best Resource on the Net for C3 Vettes! C3 Vette
Forums -> C3 Handling Components
Not Logged In! Login or Register!  Users Online: 7 / Help 
Features  Find C3 Parts on ebay in only 2 or 3 clicks!  | Add YOUR C3 to the Registry

Supporting Vendors
VetteBookStore.com
Mid America Motorworks
Volunteer Vette Products
Bair's Corvettes
CorvetteClothing.com

C3 of the Month
None Current
Enter Yours Today!
Online C3 Show
13
C3s are Registered

Vanity Plates
BAD-SVET
yellownredvette
Featured Links

Buy Now
Corvette by the Numbers
Corvette by the Numbers


The Corvette Dynasty (Hardcover)
The Corvette Dynasty (Hardcover)


Chevrolet Corvette Restoration Guide
Chevrolet Corvette Restoration Guide


Motor Trend - $5 for 12 issues.
Motor Trend
Only $5 for 12 issues.



| Hide Signatures and Profile Pics

 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page [1]  
8/8/11 7:52am - Original Message: 'At Operating Temp Brakes Drag'
rugdoz
Former Member
- Send Private Message


Merritt Island, FL - USA

Vette(s):
1981

Joined: 4/27/2008
Posts: 11

  When driveing the car during the Florida summer, the Brakes seem to expand and grab slightly on all four wheels.  The drag is enough to make it very difficulte to push the car, in drive the car will roll, but I notice the slite change when hot.  Once the car is cooled, in just a few minuets the pressure is off and you can rock the car easily.  I have truly changed everything except the steal lines and am wondering if this is normal.  Only in the summer when the outside temp is 90 plus do I notice it.  Is it the nature of the system?  Thanks!   

 Reply Reply  Quote Reply w/Quote
 
Support C3VR!
Suport our advertisers
8/8/11 9:54am - Reply: 'At Operating Temp Brakes Drag'
anips
Standard Member
- Send Private Message


sonoma, CA - USA

Vette(s):
72 LT-1 AC coupe,69 l-36 coupe

Joined: 8/9/2002
Posts: 783
which of the 4 are sticking, it could just one or all, can't realy say till you find out, it could be the proportioning valve, sticky pistons, did you replace all the brake hoses, air in the line,  the booster, when you did the job did you put a dab of antiseize on all the moving parts, is the parking brakes adjusted correctley,pull the wheels off and get dirtyWits End.  oh yea, did you flush the brake sys before you did the job so as to remove the dirty brake fluid out before you installed your new parts?anips2011-08-08 08:24:23

____________________________________
 Reply Reply  Quote Reply w/Quote
8/8/11 1:42pm - Reply: 'At Operating Temp Brakes Drag'
rugdoz
Former Member
- Send Private Message


Merritt Island, FL - USA

Vette(s):
1981

Joined: 4/27/2008
Posts: 11
The issues accures only when everything is hot...
Flushed the system from the top...
  New proportioning valve
  New steal flex lines
  New silver wearever pads
  New Vacume assist
  3rd new master cylinder.
All of these items I installed myself and I am confident they are in correctly. Its an 81 so I have the headers so it is hot under there...I'm thinking heat is expanding the system, maybe moisture.  I Don't have the symtom when the master cylinder is cool.  Thinking heat shield on the headers and flushing again with a better fluid possibly.
 
 
 
 
 
 Reply Reply  Quote Reply w/Quote
8/8/11 5:27pm - Reply: 'At Operating Temp Brakes Drag'
rugdoz
Former Member
- Send Private Message


Merritt Island, FL - USA

Vette(s):
1981

Joined: 4/27/2008
Posts: 11
Just got home and had the symptom, poured refrigerated Ice water on it and it started to roll freely.  Not sure what to do to keep the master cylinder cool, any thoughts? 
 Reply Reply  Quote Reply w/Quote
8/9/11 8:14am - Reply: 'At Operating Temp Brakes Drag'
anips
Standard Member
- Send Private Message


sonoma, CA - USA

Vette(s):
72 LT-1 AC coupe,69 l-36 coupe

Joined: 8/9/2002
Posts: 783
as far as brake fluid dot 4 works for me,  maybe you are over filling the master cyl., take some out, 1/4" from the top is ok.

____________________________________
 Reply Reply  Quote Reply w/Quote
8/9/11 12:15pm - Reply: 'At Operating Temp Brakes Drag'
Adams' Apple Lifetime Member
Lifetime Member
Moderator
- Send Private Message


Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19458
Definitely NOT normal. Usually, this is a sign of either the hoses having internal damage, or the master cyl. is not venting(releasing) properly. You have changed the hoses to braided steel lines, from what I understand, and have replaced the master 3 times.
When did this problem start? Before or after all of the changes? OR...have you been replacing these parts to try to correct the problem?
I also think if the master is too full, it might contribute to this....


____________________________________
Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
 Reply Reply  Quote Reply w/Quote
8/22/11 4:27am - Reply: 'Re: At Operating Temp Brakes Drag'
rugdoz
Former Member
- Send Private Message


Merritt Island, FL - USA

Vette(s):
1981

Joined: 4/27/2008
Posts: 11

Glad to know it is not normal, thought so.  3 days ago I noted that only the rears were warm and apparently dragging.  I took the master cylinder off and spaced it further from the power assist with washers the problem seems to have gone away.  My thinking was maybe the rears engage first and when I put it together I could not find a gasket or the pieces that shop manuels show that was never there, spacing was the issue.  Thanks all!      

 Reply Reply  Quote Reply w/Quote
8/22/11 7:02am - Reply: 'Re: At Operating Temp Brakes Drag'
Adams' Apple Lifetime Member
Lifetime Member
Moderator
- Send Private Message


Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19458
Moving the Master out from the booster can possibly create a vacuum leak, so watch out for that. There is a seal between the two, to keep booster vacuum from sucking fluid out if the master, and to just basically seal the booster pushrod.
Sounds like you may need to shorten the pushrod, anyway, if spacing the master out has corrected the problem. The pushrod length is adjustable....


____________________________________
Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
 Reply Reply  Quote Reply w/Quote
8/22/11 10:11am - Reply: 'Re: At Operating Temp Brakes Drag'
MikeMc71
Former Member
- Send Private Message


Tucson, AZ - USA

Vette(s):
1970 White L-46 Air Roadster, 1971 White LT1 Coupe, 1971 Red Auto Air Coupe, 383 stroker, 430 HP, 2002 Millennium Yellow Auto Coupe

Joined: 10/7/2007
Posts: 341
I had this exact problem with one of my cars. I had been adjusting the push rod after replacing the master cylinder to try and fine a "sweet spot" for the brake pedal. With the rod too long, the brakes began to seize heat up and seize with the rod too long. I think Adam hit the nail on the head, slightly shorten the push rod between the master cylinder and brake booster. It won't take much.....and LOSE the shims.

____________________________________

 Reply Reply  Quote Reply w/Quote
8/22/11 11:40am - Reply: 'Re: At Operating Temp Brakes Drag'
anips
Standard Member
- Send Private Message


sonoma, CA - USA

Vette(s):
72 LT-1 AC coupe,69 l-36 coupe

Joined: 8/9/2002
Posts: 783
<DIV style="BORDER-RIGHT: 1px dotted; BORDER-TOP: 1px dotted; BORDER-LEFT: 1px dotted; WIDTH: 90%; BORDER-BOTTOM: 1px dotted; BACKGROUND-COLOR: #eeeeee; align: center|/IMG||B|Adams' Apple said:|/B| Definitely NOT normal. Usually, this is a sign of either the hoses having internal damage, or the master cyl. is not venting(releasing) properly. You have changed the hoses to braided steel lines, from what I understand, and have replaced the master 3 times. When did this problem start? Before or after all of the changes? OR...have you been replacing these parts to try to correct the problem? I also think if the master is too full, it might contribute to this....
makes sense, the porp. valve allows the rears to come on ahead of the fronts, with the rod too long its not letting the brakes to completely release, adjust the rod with some free play like you might do a clutch maybe a 1/8" or so.

|UPDATED|8/22/2011 9:40:08 AM (AZT)|/UPDATED|


____________________________________
 Reply Reply  Quote Reply w/Quote
8/22/11 11:57am - Reply: 'Re: At Operating Temp Brakes Drag'
anips
Standard Member
- Send Private Message


sonoma, CA - USA

Vette(s):
72 LT-1 AC coupe,69 l-36 coupe

Joined: 8/9/2002
Posts: 783
the edit thing still needs some tuning as evident on my above post, I will post it again..................makes sense, the prop. valve allows the rears to come on before the fronts, with the rod too long its not allowing the brakes to release completeley, adjust some freeplay into the rod as you might with a clutch, but maybe a 1/8" or so.

____________________________________
 Reply Reply  Quote Reply w/Quote
8/22/11 12:22pm - Reply: 'Re: At Operating Temp Brakes Drag'
Adams' Apple Lifetime Member
Lifetime Member
Moderator
- Send Private Message


Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19458
I've replaced the masters on quite a few Sharks over the years, and I have seen some that the piston in the master, where the pushrod fits, is NOT the same depth, or shape, as the one I took off. Sometimes it simply requires a change of the length of the pushrod(adjustment)....sometimes ya just have to get the correct master. I would definitely be leaning towards a small adjustment in this case, IF the dragging when hot is the ONLY issue with the brakes.

____________________________________
Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
 Reply Reply  Quote Reply w/Quote
 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page [1]  
 Forums -> C3 Handling Components
(Moderator: Adam Wartell, Norsky, Adams' Apple)
 

 
Official C3 Vette Registry Community:
Home | Forums | Email | Who's Online | Clubs | Events | Member Stats

Other Official C3 Vette Registry Areas:
Members | Research | Shop | My Account | About C3VR
 

Corvette is a registered trademark of the General Motors Corporation(GM) & Chevrolet Motor Division. Vette Registries, LLC is responsible for all site content (except for member submitted content or where otherwise noted) and does not claim or imply that Chevrolet or GM is responsible for Official C3 Vette Registry content. Vette Registries, LLC is independent from GM and is not affiliated with, sponsored or supported by GM.  Copyright/trademark/sales mark infringements are not intended, or implied and are in fact used to support GM, Chevrolet and Corvette

Official C3 Vette Registry content is Copyright 2001-2017, Vette Registries, LLC. Content may not be reused without written consent. All Rights Reserved. NS

Corvette (Vette) Model Years on this site: 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 30