brake failure fixed, now won't bleed
10-21-14, 07:56 PM
#52
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Sounds familiar to what MIDAS said they'd do to troubleshoot...Them say them's clamp each brake line wif ViceGrips! one at a time and do same thing...For some reason I didn't let them(maybe 'cause all me lines are steel braided AND it sounded insane). Another reason I didn't try this is 'cause the problem manifested right AFTER I replace the failed/leaking/OG MC but BEFORE I ever messed with/removed any calipers or lines.
I could see if it[the problem] started AFTER I rebuilt the front calipers(perhaps unnecessarily), that it could be a front line/connection/caliper. But this seems less likely since it started BEFORE....Also, I thought the rebuild was pretty easy/straightforward and the pistons cleaned up nice and polished(no pitting/corrosion).
10-25-14, 08:47 PM
#53
I got mine to bleed!!!!
It was a bad master cylinder.
The one I had was 10 years or so old and it wasn't strong enough to push the front calipers.
I had a brand new master sitting around in my closet (I bought it on sale for 10$ shipped) and it works!!!
The bleeding process was tedious but this car will now stop on a dime.
It was a bad master cylinder.
The one I had was 10 years or so old and it wasn't strong enough to push the front calipers.
I had a brand new master sitting around in my closet (I bought it on sale for 10$ shipped) and it works!!!
The bleeding process was tedious but this car will now stop on a dime.
10-28-14, 02:39 PM
#56
Dude, I would take your stainless steel brake lines off and put a OE replacement part on.
One of the fittings on the stainless steel lines could be crap and allowing some air in.
Replacement lines are "cheap", depending on your definition of cheap, and see if it gets any better. Just because the replacement is better doesn't mean it can't be the problem.
The last thing I thought could be the problem was my master cylinder.
One of the fittings on the stainless steel lines could be crap and allowing some air in.
Replacement lines are "cheap", depending on your definition of cheap, and see if it gets any better. Just because the replacement is better doesn't mean it can't be the problem.
The last thing I thought could be the problem was my master cylinder.
10-28-14, 06:16 PM
#57
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(TOTALLY ignorant on alot of this stuff)Elaborate please? Such as: what kind of tubing, what kind of ends are needed, how are they coupled to the tubing, how do you then use it? My car's not anywhere near me at the moment, I'm having trouble remembering all the piping from MC to dist.Block, to brake lines...Are there two lines from MC to the Dblock? which is which, what role does the "tubing" then play? Thanks
10-28-14, 06:31 PM
#58
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Dude, I would take your stainless steel brake lines off and put a OE replacement part on.
One of the fittings on the stainless steel lines could be crap and allowing some air in.
Replacement lines are "cheap", depending on your definition of cheap, and see if it gets any better. Just because the replacement is better doesn't mean it can't be the problem.
The last thing I thought could be the problem was my master cylinder.
One of the fittings on the stainless steel lines could be crap and allowing some air in.
Replacement lines are "cheap", depending on your definition of cheap, and see if it gets any better. Just because the replacement is better doesn't mean it can't be the problem.
The last thing I thought could be the problem was my master cylinder.
I remember trying a hand pump/vacuum device connected to the bleeder way back when problem first started...I could use it "successfully" in the right caliper bleeding sequence...BUT just for the heck of it(It would have GREAT pedal after the bleed) if I started all over again, I could pull air at every caliper again, and then lose the pedal...I just can't find where it's pulling air in and why? And I still can't see how in a pressurized hydraulic system, there can be a point where air can enter, but fluid can't escape...
Another huge problem is that you can bleed the brakes and get all the air out, and have great pedal...But it only lasts for a few days before fading...I just don't get it...
10-28-14, 11:47 PM
#59
I've tried three used and one new MC, and three different used dist.Blocks in many combinations, so I'm keen on ruling those two out...Also keen to rule out any brake line junctions because they were fine till OG MC failed and leaked...Never messed with any of these junctions when MC was replaced and problem manifested. Then, the only junctions messed with were at the front calipers when I took them off to rebuild them. ALL junctions have remained bone dry.
I remember trying a hand pump/vacuum device connected to the bleeder way back when problem first started...I could use it "successfully" in the right caliper bleeding sequence...BUT just for the heck of it(It would have GREAT pedal after the bleed) if I started all over again, I could pull air at every caliper again, and then lose the pedal...I just can't find where it's pulling air in and why? And I still can't see how in a pressurized hydraulic system, there can be a point where air can enter, but fluid can't escape...
Another huge problem is that you can bleed the brakes and get all the air out, and have great pedal...But it only lasts for a few days before fading...I just don't get it...
I remember trying a hand pump/vacuum device connected to the bleeder way back when problem first started...I could use it "successfully" in the right caliper bleeding sequence...BUT just for the heck of it(It would have GREAT pedal after the bleed) if I started all over again, I could pull air at every caliper again, and then lose the pedal...I just can't find where it's pulling air in and why? And I still can't see how in a pressurized hydraulic system, there can be a point where air can enter, but fluid can't escape...
Another huge problem is that you can bleed the brakes and get all the air out, and have great pedal...But it only lasts for a few days before fading...I just don't get it...
Honestly that's weird and I don't know what to say.
10-29-14, 05:09 PM
#60
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...I got nothing either...See my other thread/threads...
https://www.rx7club.com/1st-generati...rvice-1066049/
https://www.rx7club.com/1st-generati...rvice-1066049/
10-31-14, 04:57 PM
#61
84SE-EGI helpy-helperton
Alright - check one more thing; feel around the carpeting on the inside of the firewall at the driver's footwell. Is it wet with brake fluid?
I've had MC fail at the rubber seals on the piston shaft connected to the brake pedal actuator rod that would allow brake fluid to seep INTO the interior of the car from the pedal rod and drip down the inside of the firewall. It's hard to notice because it's dark down there and how often do you feel around it, anyway?
If that's the case - that's your problem, as the bad MC O-rings will allow air to enter the system from the pedal side and it would affect all 4-calipers when bleeding.
Check that and report back. I know you tried 3 used MC already, but if they're all old stock or have bad O-ring seal dimensions, they'd all have the same problems. My last MC rebuild I bought a complete unit from MazdaTrix and have sworn off the 'rebuild kits' which replace the O-rings only. Brakes are important to me, so they get new parts whenever available.
I've had MC fail at the rubber seals on the piston shaft connected to the brake pedal actuator rod that would allow brake fluid to seep INTO the interior of the car from the pedal rod and drip down the inside of the firewall. It's hard to notice because it's dark down there and how often do you feel around it, anyway?
If that's the case - that's your problem, as the bad MC O-rings will allow air to enter the system from the pedal side and it would affect all 4-calipers when bleeding.
Check that and report back. I know you tried 3 used MC already, but if they're all old stock or have bad O-ring seal dimensions, they'd all have the same problems. My last MC rebuild I bought a complete unit from MazdaTrix and have sworn off the 'rebuild kits' which replace the O-rings only. Brakes are important to me, so they get new parts whenever available.
11-03-14, 12:02 PM
#62
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Alright - check one more thing; feel around the carpeting on the inside of the firewall at the driver's footwell. Is it wet with brake fluid?
I've had MC fail at the rubber seals on the piston shaft connected to the brake pedal actuator rod that would allow brake fluid to seep INTO the interior of the car from the pedal rod and drip down the inside of the firewall. It's hard to notice because it's dark down there and how often do you feel around it, anyway?
If that's the case - that's your problem, as the bad MC O-rings will allow air to enter the system from the pedal side and it would affect all 4-calipers when bleeding.
Check that and report back. I know you tried 3 used MC already, but if they're all old stock or have bad O-ring seal dimensions, they'd all have the same problems. My last MC rebuild I bought a complete unit from MazdaTrix and have sworn off the 'rebuild kits' which replace the O-rings only. Brakes are important to me, so they get new parts whenever available.
I've had MC fail at the rubber seals on the piston shaft connected to the brake pedal actuator rod that would allow brake fluid to seep INTO the interior of the car from the pedal rod and drip down the inside of the firewall. It's hard to notice because it's dark down there and how often do you feel around it, anyway?
If that's the case - that's your problem, as the bad MC O-rings will allow air to enter the system from the pedal side and it would affect all 4-calipers when bleeding.
Check that and report back. I know you tried 3 used MC already, but if they're all old stock or have bad O-ring seal dimensions, they'd all have the same problems. My last MC rebuild I bought a complete unit from MazdaTrix and have sworn off the 'rebuild kits' which replace the O-rings only. Brakes are important to me, so they get new parts whenever available.
I have checked that area because I know that will happen if clutch or brake MC fails...
04-10-15, 05:40 PM
#63
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...Oh joy. It's that time of the year, heading to see my little LUCY tomorrow to try and bleed the brakes again...Only been trying to do this since 2013...This time I got four threaded pipe caps to cap 3 of the 4 four lines at a time whilst bleeding to try and rule out a single caliper. Originally back in '13, when I installed a replacement MC, and all the problems began: I didn't "bench bleed" the MC/prop. valve assembly. But SURELY this can't be the source of air after years and hundreds of ounces of brake fluid run thru the system, right? Anyone have any other suggestions?
04-13-15, 07:16 PM
#64
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The "caps" I got didn't werk...I capped all caliper lines except pass. rear to start...Used the vacuum pump thing, just pulled bubbles upon bubbles eternally...Went and pumped up the pedal and stood on it, pedal slowly dropped while it pushed fluid out of every cap...
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