Brake bleeding after system overhaul question
Thread Starter
Pro
Joined: Jul 2011
Posts: 511
Likes: 34
From: NW Michigan
Brake bleeding after system overhaul question
Replaced all four calipers, pads, soft lines, fluid, etc. I bled the brakes in the order I found here on the forum- last: right front. I'm using the Motive pressure bleeder but adding fluid to the master only to avoid any accidental mess. All three other calipers seem bled and bubble free, but this last one is making me question my procedure. I've run at least 20 oz of fluid through it (4 oz at a time to make sure the master stays topped off), but I still get a steady stream fluid at first crack followed by a steady stream of small bubbles in fluid... These couldn't be introduced at the bleeder screw could they? (With the positive pressure- 5lb or so of the Motive I don't see how, but???) Any advice for a brake bleed newbie?
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,600
Likes: 7,046
From: New Or-leens Loo-z-anna
I just rebuilt my brakes and had trouble with the passenger-side....I think because of the "over/under/around/down/across/up/around" of the brake line, fluid manages to work it's way past the air in the line.
It took me longer to do that caliper than all the others....I even tried a Mighty-Vac to pull 25 "pounds" of vacuum at the bleeder-screw before "cracking'' it...
And I do think air can be drawn past the bleeder screw threads if it is loosened too much when I used the Vac.
Wait for the experts to give you some good advice.
It took me longer to do that caliper than all the others....I even tried a Mighty-Vac to pull 25 "pounds" of vacuum at the bleeder-screw before "cracking'' it...
And I do think air can be drawn past the bleeder screw threads if it is loosened too much when I used the Vac.
Wait for the experts to give you some good advice.
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
Get yourself a vacuum bleeder, with a good vacuum pump gun, some clear tubing and a jar, set up for that (they sell kits, just for that) and you will save yourself a lot of trouble, frustration and beer. And get the good kit too, you get what you pay for. Because your personal time is always worth something.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
Pro
Joined: Oct 2013
Posts: 557
Likes: 3
From: El Sobrante CA
Get yourself a vacuum bleeder, with a good vacuum pump gun, some clear tubing and a jar, set up for that (they sell kits, just for that)
If you have a compressor, Harbor Freight sells a nifty, inexpensive vacuum bottle/kit. Works very well; much easier than hand pumping. Unfortunately, the feed bottle isn't compatible with the older 'Vette/GM master cylinders, so 'liquid refreshment' is rather frequent.
If you have a compressor, Harbor Freight sells a nifty, inexpensive vacuum bottle/kit. Works very well; much easier than hand pumping. Unfortunately, the feed bottle isn't compatible with the older 'Vette/GM master cylinders, so 'liquid refreshment' is rather frequent.
Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
I have never had luck with the two person method on mine. If you use the Motive Pressure system as directed, fluid in the pump tank @ 10-15 psi. Tap (with gusto) the calipers with a rubber mallet while bleeding. You will get all the air out. See Motive's website for instructions for using clamp on master cylinder instead of their chains. Even then put a wad of rags under the mc.
Thread Starter
Pro
Joined: Jul 2011
Posts: 511
Likes: 34
From: NW Michigan
Further work with the Motive, and I think all air is out. I'll road test later this week. I could still get a small stream of bubbles when the bleeder was barely cracked, but larger turns (or stopping and starting) gave me clear fluid. No idea why.
I did not bench bleed the master but did keep a small amount of fluid in it from the original contents...
I did not bench bleed the master but did keep a small amount of fluid in it from the original contents...
Advanced
Joined: Nov 2012
Posts: 91
Likes: 0
From: Andover Mn
Been through the same thing, and IMO dry lines and filling them first time damn air bubbles can stick almost anywhere. I didn't think it was a good idea but have heard of many others doing what I did. Reusing the fluid and putting it back in the motive pump container and finally did get great pedal. Before I bought the motive unit, I tried the 2 person pump thing and never got an acceptable pedal.
Mark Smith
Mark Smith
Le Mans Master
Joined: Aug 2010
Posts: 5,339
Likes: 546
From: Central Texas
I have never had luck with the two person method on mine. If you use the Motive Pressure system as directed, fluid in the pump tank @ 10-15 psi. Tap (with gusto) the calipers with a rubber mallet while bleeding. You will get all the air out. See Motive's website for instructions for using clamp on master cylinder instead of their chains. Even then put a wad of rags under the mc.
