Pressure Brake Bleeding?
Thread Starter
Instructor
Joined: Dec 2007
Posts: 245
Likes: 2
From: Jersey shore NJ
Pressure Brake Bleeding?
I have searched the forum and read almost every post and have not seen an answer to this. In my manual for a 76 it says if you pressure bleed the Brake system you need to make sure that the proportioning valve is held in the open position and they give tool # j-23709 to use? I have not read anyone saying that this was an issue? Please help!
Burning Brakes
Joined: Oct 2006
Posts: 1,006
Likes: 28
From: Lutz Florida
I just bled my entire system with a Motive bleeder with no problems (silicone). Worked from back to front per my shop manual. Maybe that applies if you are filling and pressure bleeding a new system that has no existing fluid in the lines?
Hopefully someone else that knows for sure will jump in and answer this one.
Hopefully someone else that knows for sure will jump in and answer this one.
Le Mans Master
Joined: Dec 2007
Posts: 6,422
Likes: 591
From: McHenry Illinois
Since most brake pressure bleeders pressurize both front and rear parts of the mastercylinder the proportioning valve should stay centered especially since the bleeder pressure is so low it should not cause a problem. I made my own bleeder from a small weed sprayer from ace hardware and an old m/c cover. Had to solder up the vents in the cap and solder a hose nipple to it, but I made for about $15.
Racer
Joined: Oct 2004
Posts: 281
Likes: 9
From: New England
I also have a 1976 and just replaced all of my brake lines and I bled my entire system with a Motive bleeder with no problems .I have never heard of this tool # j-23709 , I have had my car for over 30 years and I have never read anything about one. Worked from back to front per my shop manual too. Came out great without a problem, LOVE THAT MOTIVE BLEEDER!!!!!! Worth every cent!!! Spend the extra money and get all three adapters and you can do any car on the market. I use it on all om cars from 1076 to 2007 Chev Motorhome.
Someone also mentioned having to run the car while bleeding, that is normally required on new car with Anti-lock brakes while bleeding by using the brake pedal way. Not required to do on a new car with antilock-brakes if using the Motive brake bleeder. LOVE THAT MOTIVE BLEEDER!!!!!!
Someone also mentioned having to run the car while bleeding, that is normally required on new car with Anti-lock brakes while bleeding by using the brake pedal way. Not required to do on a new car with antilock-brakes if using the Motive brake bleeder. LOVE THAT MOTIVE BLEEDER!!!!!!
Last edited by dariopop; Jan 6, 2008 at 12:04 AM.
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Le Mans Master
Joined: Mar 2001
Posts: 6,640
Likes: 287
From: Ann Arbor Michigan
The special tool is used to hold open the Metering Valve in the front brake system. The Metering function is used to holdoff pressure to front disk brakes until you overcome the return springs in a rear drum brake. Since all C3 Vettes have 4 wheel disck brakes, there is no metering function so the special tool is not needed.
Le Mans Master
Joined: Mar 2001
Posts: 6,640
Likes: 287
From: Ann Arbor Michigan
Drifting
Joined: Sep 2006
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From: MS
Melting Slicks
Joined: Aug 1999
Posts: 3,123
Likes: 13
From: Hollywood, Florida
Since most brake pressure bleeders pressurize both front and rear parts of the mastercylinder the proportioning valve should stay centered especially since the bleeder pressure is so low it should not cause a problem. I made my own bleeder from a small weed sprayer from ace hardware and an old m/c cover. Had to solder up the vents in the cap and solder a hose nipple to it, but I made for about $15.
I just finished building one also. Old weed sprayer, some vinyl tubing, a couple of barb fitting into an old MC cover. Total $$$ was $7 in parts (the weed sprayer was retired years ago, so ...no cost
)
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
I have used these tools - in fact I still have one from the early '70s for "Ford" valves in my tool box. They screw in in place of the switch and hold the slide in the center position while pressure is applied for bleeding. Without the tool, the slide will go toward the side you are bleeding and close it off.
Le Mans Master
Joined: Mar 2001
Posts: 6,640
Likes: 287
From: Ann Arbor Michigan
See attached link. As I said in my other post, the tool mentioned is for cars with Metering valves. Vettes don't have metering valves.
http://www.autozone.com/az/cds/en_us...rInfoPages.htm
http://www.autozone.com/az/cds/en_us...rInfoPages.htm
Last edited by Duke94; Jan 6, 2008 at 07:56 PM.
Drifting
Joined: Oct 2004
Posts: 1,259
Likes: 7
From: Ontario
See attached link. As I said in my other post, the tool mentioned is for cars with Metering valves. Vettes don't have metering valves.
http://www.autozone.com/az/cds/en_us...rInfoPages.htm
http://www.autozone.com/az/cds/en_us...rInfoPages.htm
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
76projectstingray: If you have one, sure! Particularly if you use the pedal bleed method.
Duke94: not true - they were used with Proportioning valves and distribution valves (which the 69-70 do have).
If you do not use the "tool", and use the pedal bleed method, the slide can be pushed to the "open" side with sufficient pressure to cause it to "stick" in that direction. Pressure bleeders have much less pressure than that which is created by pushing the pedal so it usually isn't a problem.
Duke94: not true - they were used with Proportioning valves and distribution valves (which the 69-70 do have).
If you do not use the "tool", and use the pedal bleed method, the slide can be pushed to the "open" side with sufficient pressure to cause it to "stick" in that direction. Pressure bleeders have much less pressure than that which is created by pushing the pedal so it usually isn't a problem.
Burning Brakes
Joined: Aug 2004
Posts: 856
Likes: 2
From: Tyler Texas
