help bleeding brakes...
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Joined: Jul 2010
Posts: 1,292
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From: Dirty Jerz
help bleeding brakes...
Well as the story goes my rear brake calipers were seized so I wanted to replace them. Saw a sweet deal online for all four so I bought them. Replaced the front and rear caliper as well as the front hardlines as the nut was rounded off so I got two new ones from mazdatrix.
Was tring to bleed the brakes but the pedal wasn't getting hard, no pressure. Doesn't seem like fluid is getting to the calipers so I can't bleed it. When the brake pedal is being pumped it sounds like air is being sucked or w/e in the master cyl or brake booster idk. I didn't mess around with the master cyl so I'm hopeing it hasn't gone bad.
Any suggestions well help greatly.
Was tring to bleed the brakes but the pedal wasn't getting hard, no pressure. Doesn't seem like fluid is getting to the calipers so I can't bleed it. When the brake pedal is being pumped it sounds like air is being sucked or w/e in the master cyl or brake booster idk. I didn't mess around with the master cyl so I'm hopeing it hasn't gone bad.
Any suggestions well help greatly.
Although certainly possible it's not, let's assume the MC is fine.
Under normal conditions you'll hear "air noises" from the booster because that's how it works, so you can discount that.
That said, I must add that were I in your position I'd replace the MC while the whole system is down, just to be safe and more importantly, so I only had to bleed it once...
Having replaced all four calipers and a couple of hardlines, there is a lot of air in the loop and air is predictable, it wants to rise to the highest point in the loop, which in this case is the MC.
In essence, you're vapor locked.
With your trusty assistant holding down the brake pedal, try cracking the hardlines at the MC (have a rag handy). This is basically a quick & dirty bench bleed of the cylinder and should get you past the air lock and pumping fluid to the calipers.
Good luck.
Under normal conditions you'll hear "air noises" from the booster because that's how it works, so you can discount that.
That said, I must add that were I in your position I'd replace the MC while the whole system is down, just to be safe and more importantly, so I only had to bleed it once...
Having replaced all four calipers and a couple of hardlines, there is a lot of air in the loop and air is predictable, it wants to rise to the highest point in the loop, which in this case is the MC.
In essence, you're vapor locked.
With your trusty assistant holding down the brake pedal, try cracking the hardlines at the MC (have a rag handy). This is basically a quick & dirty bench bleed of the cylinder and should get you past the air lock and pumping fluid to the calipers.
Good luck.
replace the master cylinder. its only like 30 bucks from autozone. bench bleed it like stated before then start rear passenger right till fresh fluid comes out. close it off rear left cap,front right cap, front left cap.... finished. also there is a write up on here to make a master cylinder brace which makes the brake pedal feel so much better. (3/4 steel, long bolt washer nut, and 30min of time getting it right. cheapest >$5 mod available
Thread Starter
Joined: Jul 2010
Posts: 1,292
Likes: 4
From: Dirty Jerz
Gravity bleed to allow fluid to enter the brake lines from master. Front end of car needs to be higher than rear (raise, ect.):
Rear: open bottom bleeders.
Front Open bleeders.
Put a whole bottle of brake fluid in the master (flip it upside down, leave it in there). The brake fluid will flow down as the air will want to travel up (physics). Eventually fluid will reach the calipers and drain out (have a pan or something to catch fluid). When you have fluid coming out. Close all 4 bleeders. You should be able to start bleeding.
Rear: open bottom bleeders.
Front Open bleeders.
Put a whole bottle of brake fluid in the master (flip it upside down, leave it in there). The brake fluid will flow down as the air will want to travel up (physics). Eventually fluid will reach the calipers and drain out (have a pan or something to catch fluid). When you have fluid coming out. Close all 4 bleeders. You should be able to start bleeding.
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Or go to HF and get a cheap mityvac. Use the bottle attachment to pressurize fluid from each caliper bleeder through the master cylinder. Also, verify your brake pedal free-play is within spec. You really need to make sure it's set properly first, otherwise the ports inside the master cylinder could be covered up and won't allow for fluid take-up.
Other methods include:
-beating lightly on the calipers with a rubber mallet to loosen any free bubbles in the system, then cracking the bleeder open.
-Bleeding the system at the master cylinder lines. (very important)
Also, make sure your car isn't running when you do this. You'll get a better feel for the pedal without vacuum assist from the booster.
Other methods include:
-beating lightly on the calipers with a rubber mallet to loosen any free bubbles in the system, then cracking the bleeder open.
-Bleeding the system at the master cylinder lines. (very important)
Also, make sure your car isn't running when you do this. You'll get a better feel for the pedal without vacuum assist from the booster.
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