Topic: looking for an opinon
in Forum: C3 Engines, Driveline and Handling
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I have been working on my brake problems for about a month(weather and work)(1)replaced master cylinder bench bleed it(2) replaced left rear caliper(3) replaced hard line to new caliper.I bleedthe system according to maunal.Idid it with 2 people and auto bleeder with the hoses.both ways I get fliud out of the bleederd,but my pedel still gose to the floor like I have no brakes.Any sugestions on what I should to do or what I didn't do?
Thanks Rick
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Frederick, MD - USA
Joined: 9/8/2003
Posts: 3398
Vette(s): 1969 convertible L71 427/435 4-speed black interior
Several issues you might be facing. The rubber brake hoses could be collapsing internally...no matter how good they look on the outside. If you have no idea how old the hoses are, consider them to be 35 year old originals and replace them. Money well spent.
Gunslinger 2010-04-08 13:20:12
You could have a caliper piston seal that isn't leaking, but sucking in air...that happened to me. Rebuild or replace all the calipers to eliminate that possibility.
You might have DOT3 brake fluid mixed with DOT5 silicone fluid...they are absolutely not compatible and will give you a very bad pedal...spongy to the max. You will never be able to properly bleed the air out of the system if that's the case. You will often see a cloudy mix in the master cylinder, but not always. If you have DOT3 and 5 mixed, you have to completely...and I mean completely, flush the entire system with fresh fluid and blow it out with compressed air to purge any remnants of the bad mix. Some will say to use an alcohol solution to flush it out before the compressed air. If you replace the hoses it's good to flush everything anyway.
I think your problem is one of those three possibilities.
I'm getting good flow out of the front ,but the back I'm getting flow mixed with air bubbles.I start my nights tomorrow so when I finsh up I'm taking it to the shop to have it checked out.
I gave it a hell of a try
Thanks Rick
Go power is good, but "whoa" power is essential! Hope you get it all straightened out!
Barry
Lifetime MemberHOWELL, NJ - USA
Joined: 5/18/2004
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Vette(s): 1979, Targa Blue (72 Color), Pace Car rear spoiler, L88 hood, Dark blue factory interior, 525HP 406, HD 700R4, 370 gears,Steeroids, composite rear spring, TT IIs wrapped in T/A Radials.
Rick, are the rest of the calipers the originals? And are the hoses the originals?
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Hhmmm, sounds vaguely familiar. To make a long story short, I replaced a master cylinder, lines, rotor, and bled, bled, and bled the brakes. Turned out to be a leaking piston in the caliper that I know was dry when I started. With that being said after replacing the caliper I bled the brakes once and problem solved. My suggestion is work from the caliper up to the master cylinder.
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Mounds View, MN - USA
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When a customer has this problem (which happens fairly often), we suggest pressure bleeding. There is a post here about how to make a cheap one. It almost always solves the problem. It is probably because one caliper is sucking air even though it is not leaking fluid. The seals do a much better job under pressure than suction.
Larry
Larry
Because of my work schulde(work when schulded) I am going let my repair shop finsh the job so I can be ready to cruise next weekend.With what i did do it was a learning experience.Besides I am keeping not for the next one.
in Forum: C3 Engines, Driveline and Handling
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