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: 24 / Help 
Features  Find C3 Parts on ebay in only 2 or 3 clicks!  | Add YOUR C3 to the Registry

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

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

Vanity Plates
70BEAST
Guest
Featured Links

Buy Now
Corvette Masterpieces: Dream Cars You'd Love to Own (Hardcover)
Corvette Masterpieces: Dream Cars You'd Love to Own (Hardcover)


Corvette 50th Anniversary
Corvette 50th Anniversary


Chevrolet Corvette Restoration Guide
Chevrolet Corvette Restoration Guide


Kindle
Kindle



| Hide Signatures and Profile Pics

 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page 1 [2]  
 
Support C3VR!
Suport our advertisers
6/10/12 2:43pm - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
corvette440hp Lifetime Member
Lifetime Member
- Send Private Message


Joined: 7/2/2006
Posts: 8205
Dave for what it's worth: I used a digital cliper to check the copper washer but this was after I tightened them in place. So, here is what I came up with .400 inside diameter, .627 outside diameter, .075 thickness. I tend to get very exacting (go overboard) with things. You (in my mind) can't over engineer.   

____________________________________
corvette440hp
 Reply Reply  Quote Reply w/Quote
6/11/12 2:22am - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
daveo76
Standard Member
- Send Private Message


Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 829
Man, folks were not kidding when they said this is one of the toughest jobs on a shark. I'm getting closer, but still not there yet. I replaced the M/C with a different one from Autozone, bench bled it and now I'm bench bleeding it again, because there were still bubbles coming out after it was on the car. And those cheesy plastic bleeder fittings that come with a M/C are apparently one time use only so now tomorrow I'll be buying another bleeding kit. I'm also going to put plugs in the outlets and test - the pushrod should be rock hard if it was done correctly.

Different note: "differential pressure valve" (AKA proportioning valve). I need some opinions here: I've double and triple checked the brake light in the dash. It comes on with the parking brake pulled up as it should but it is not on any other time. And I know the circuit works because I pulled the connector off the valve and grounded it - light comes on. And I know the switch in the valve works because I tested it. So I'm 99% sure the switch is centered. The only thing it could be is if the o-rings on the piston or "spool" are bad such that fluid is being passed from one side to the other. Can this happen? What's the verdict - should I replace that guy or does it sound OK? 

Finally, I got the copper crush washers and installed those on my hoses. I also pulled off my front calipers again and double checked everything there (since I rebuilt them) and made sure no sign of leaks. So tomorrow it's bench bleeding for the M/C. (my third try) and then re-install and see what happens. I'd really like to be able to gravity bleed - seems like that's the safest way to go in light of that crazy valve that can get off-centered. Thanks, guys. Sorry for the long post!


____________________________________

 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
 Reply Reply  Quote Reply w/Quote
6/11/12 11:26am - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
corvette440hp Lifetime Member
Lifetime Member
- Send Private Message


Joined: 7/2/2006
Posts: 8205
Dave, I hate to tell you that the gravity bleeding is futile. Maybe it might work for you....I only hope for your sake that it works.

____________________________________
corvette440hp
 Reply Reply  Quote Reply w/Quote
6/11/12 1:05pm - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
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: 19448
Hat's off to ya, Dave...I'm getting frustrated just READING this...and YOU'RE doing all the werk!

Anyway....here's what I would suggest at this point. You have to determine WHERE in the system the problem is. So...start with the master. Disconnect the lines, and verify you have fluid UNDER PRESSURE coming out of both fittings there. Not just fluid running, but fluid under pressure.
Then, connect the lines back up, and go to the next junction...the p-valve. Disconnect the lines to the front brakes, one at a time, and verify fluid under pressure. If you have good pressure coming out of the master, but not out of the p-valve, you'll need to replace the valve. Cross leakage inside of the p-valve will not cause the problem you have, so even if you left the seals off, you should still get pressure from both ends.
If you happen to get pressure on both the fittings coming out of the p-valve, then your problem HAS to be in the lines to the front calipers, either the hard lines, or the "new" flex lines. Make sure there is nothing restricting the flex lines....they can get crap in them from the factory, or by sitting on a shelf. If they get twisted, they can collapse, too, so just be sure they are free to flow.
From everything I have been reading, your rear brakes will bleed with pressure no problem, but the fronts are just dribbling. If the master is working, the only other possibility would have to be the p-valve, or a restricted line/hose.

When I say "under pressure", I don't necessarily mean under full pedal pressure...just enough to determine there IS pressure...the kind that might skwert ya in the eye, so be careful.

I would also seriously start thinkin about renting/loaning/buying/building a pressure bleeder....

Good Luck...hope ya get it figured out & fixed soon. I would have already beat the he!! out of it at this point...  LOL


____________________________________
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
6/11/12 2:49pm - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
daveo76
Standard Member
- Send Private Message


Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 829
Thanks, Joel and Larry!  Yep, good advice about starting at the M/C and working down from there.  That's definitely my plan.  I almost think it has to be in the M/C or valve since I'm having problems with both fronts.  (and I know the single front hard line from M/C to valve is OK).  Unless there are problems in more than one line which I guess could happen.  A couple more questions: 1) when you say test under pressure, can I do that with a "thumb test" or do I need to rig up some kind of gauge?  2) Pressure bleeder: I've heard the $60 parts store versions have a hard time sealing to the old GM cast iron M/C's - any truth to that?  You're probably referring to the professional version, but I'm not sure I'll be able to find one of those in my usual list of "tool loaner" friends.  But I think I'm done with the sucky sucking (MityVAC) method - I think it's causing more problems than it's solving.  Thanks again - I'm pretty sure I'll nail this eventually.  All part of the fun! 

____________________________________

 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
 Reply Reply  Quote Reply w/Quote
6/11/12 3:56pm - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
yostusota
Former Member
- Send Private Message


York, PA - USA

Vette(s):
1969 daytona conv. all original 350 350 380 4 sp w/air..and hard top

Joined: 5/18/2010
Posts: 1518
Sounds like you're having a nightmare with these brakes..can't say I haven't had my share of them myself..those brass washers ..seals usually don't come with hoses anymore..not sure why because they used to but a few years ago I noticed that they didn't come with them..I think the biggest problem is..if they are not included they should be a suggested part as they really only work once..maybe twice if you have to..don't feel bad about not putting them in..I can't count how many times I do stuff like that and knock myself up and down once I figure out what I did wrong..hopefully with the brass washers installed the brakes bleed out as easy as they can..one thing I do to help bleed is leave old hoses on the front and get the back done ready to bleed..then I pinch off the old hoses in the front with vice grips and bleed the back completely..then install new hoses on the front and it usually bleeds out pretty fast..I have done this a couple of times and haven't fought it as much as I did it without being pinched off...also...when I bled the front I jammed a small screw driver in between the pad and rotor of the rear on both sides..this keeps the rear pistons from moving..makes all the pressure go to the front instead of using some of it to go to the rear..this part was for when you pump the pedal to bleed..I may have done the same thing to the front at the same time but can't remember...the reason I did this was to increase the amount of fluid flow to the caliper that had the bleeder open...btw..I didn't use any type of power bleeder to do this even though I have you 2...I have used the old hose dipped in a milk jug tool immersed in brake fluid and just pump away..really works as it pushes out the air and sucks in fluid at the same time..really hope this helps as it did work for me.

____________________________________

My first parade at Carlisle 2010
 Reply Reply  Quote Reply w/Quote
6/11/12 3:57pm - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
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: 19448
Dave, put yer thumb/finger over the hole, and make sure there is enough pressure to blow some fluid out..a good stream, not just a dribble.

Don't know about the $60 bleeder sealing, but my $300+ one leaks a bit, too....that's what rags/paper towels are for...LOL



____________________________________
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
6/11/12 8:18pm - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
corvette440hp Lifetime Member
Lifetime Member
- Send Private Message


Joined: 7/2/2006
Posts: 8205
Dave, this is what I used. It comes with J hooks (4) wing nuts (4) and 2 dinky chains. The best thing to create a good seal is to forget the J hooks and chain junk. Use two C clamps instead so that when you pump up the pressure it doesn't squirt from unsealed gasket areas. Here is the link:.............

http://www.summitracing.com/parts/MVP-0105/



____________________________________
corvette440hp
 Reply Reply  Quote Reply w/Quote
6/11/12 10:38pm - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
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: 19448
The real prollem with the leakage from the pressure bleeders is folks thinking you need 30-40 psi to get the job done....truff is, 10psi is all ya need. I don't think I've ever pumped mine much over 15psi. Mine leaks mostly because the rubber gasket is old, has had brake fluid on it for 10 or more years, and it's just swelled, and mooshy. I really should get a replacement....one of these days...

____________________________________
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
6/12/12 12:39am - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
philip
Former Member
- Send Private Message


Marana, AZ - USA

Vette(s):
1982 Silver Blue

Joined: 4/8/2010
Posts: 104
corvette440hp said: Dave, this is what I used. It comes with J hooks (4) wing nuts (4) and 2 dinky chains. The best thing to create a good seal is to forget the J hooks and chain junk. Use two C clamps instead so that when you pump up the pressure it doesn't squirt from unsealed gasket areas. Here is the link:.............

http://www.summitracing.com/parts/MVP-0105/



x2 on  this trick. I use a 1/2" thick piece of flat steel that is 2" wide and 4" long on the bleeder cover and secure it with one C clamp in the middle over the divider wall in the casting. Pump up to 12-14 psi and start bleeding.

The copper washers will get hard over time, even unused new ones. If you anneal them they become soft again and will seal better. I put a piece of tubing or a welding rod in the vise, place the washers on the rod, heat until glowing and quench in a pan of cool water. It makes them soft and they seal easily when the bolt is torqued to spec.


____________________________________
1977 Nova 1982 Corvette   

The Toy Box
 Reply Reply  Quote Reply w/Quote
6/12/12 2:16am - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
daveo76
Standard Member
- Send Private Message


Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 829
Thanks guys!  Lots of good advice out there.  Think I'm getting closer on this thing.  Tonight I redid the bench bleeding of the M/C.  I'm very confident it's right this time and the part is good.   No bubbles at all, no matter which way it's oriented and there is almost no give with the ports plugged.  I re-installed and hooked up the outlets.  I'm in the process of trying my gravity bleed method right now.  I'm doing front and back on the driver side simultaneously.  The back is dripping like mad, but it was more or less already bled.  The front is dripping, but more slowly.  I know there is a good chance that this won't work, but I figure what's the harm in trying.  I'll try the pass. side tomorrow and see if I have a hard peddle after that.  I'm sure it's even less likely it will work on the pass side, but we'll see.  I'm a little worried that my earlier tries of using the vacuum bleeder could have collapsed my new front hoses.  There were a couple of times I tried applying up to 20" Hg.  in an effort to get fluid to flow to the fronts.  Hmmm. 

Well if I still don't have a hard pedal after tomorrow night I'll do what Joel says and do the thumb test on lines/hoses.  And I'll try and borrow a pressure bleeder - I thought of a few more buddies that may have one.  When you guys use those do you do each wheel separately, all four simultaneously or front/back on one side simultaneously?  (or some other combo??)

Thanks again for all the support - this site is tremendous that way!  (And no one called me an idiot for forgetting the sealing washers Embarrassed - some other sites I'm not so sure that wouldn't happen!)


____________________________________

 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
 Reply Reply  Quote Reply w/Quote
6/13/12 12:53am - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
daveo76
Standard Member
- Send Private Message


Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 829
WhoHoo!  Hard pedal, finally! Party  Gravity bleeding actually seems to have worked.  I was most worried about the pass side front, but after about 15 minutes fluid finally started flowing.  I let it drip drip drip for about a half hour after that (inner RR was going at the same time) and then let the outer RR flow for a few minutes and then double checked all bleeders were tight and voila! hard pedal.  Thanks for all the advice and support, guys.  Think I'll go crack a beer to celebrate.  

____________________________________

 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
 Reply Reply  Quote Reply w/Quote
6/13/12 7:26am - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
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: 19448


____________________________________
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
6/13/12 10:09am - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
corvette440hp Lifetime Member
Lifetime Member
- Send Private Message


Joined: 7/2/2006
Posts: 8205
Dave, I am so happy that things worked out for you that I might have a beer and smoke a cigarette in your honorWink...............NOT really I hate beer and don't smoke, but you get the idea! I really appreciate people who never say dieClap. You never gave up and found and admitted to a slip-upThumbs Up. As you mentioned other sites picking on peopleThumbs Down, it's great that it's not done hereClap. Now on to the next challengeThumbs Up 

____________________________________
corvette440hp
 Reply Reply  Quote Reply w/Quote
6/13/12 10:32am - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
daveo76
Standard Member
- Send Private Message


Vancouver, WA - USA

Vette(s):
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Joined: 8/25/2005
Posts: 829
Yep!  And that next challenge (all I have left, really) is dropping in the engine and then getting it running.   Can't wait for that fun and excitement.  Thanks again, guys!

____________________________________

 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
 Reply Reply  Quote Reply w/Quote
6/13/12 4:41pm - Reply: 'Re: Brake Bleeding: What am I doing wrong?'
Jaws79 Lifetime Member
Lifetime Member
- Send Private Message


Sykesville, MD - USA

Vette(s):
1979 Corvette Coupe Corvette Light Blue Midnight Blue interior Mirrored Glass T-tops

Joined: 4/27/2008
Posts: 4211
Hopefully dropping in the engine goes smoother! Glad you were able to get things working like you wanted! Betcha it was a lot easier workinc on that master cylinder and proportioning valve with the engine out! Great job!
 
Barry
 
Clap


____________________________________
"Down on the Boardwalk...

(Click image to see a larger version}
 
Lifetime Member #181
 Reply Reply  Quote Reply w/Quote
 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page 1 [2]  
 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