Curious what everyone does when they are changing brake pads. Do you just squeeze the piston back into the caliper and let the fluid fill back up in the master cylinder, or do you loosen the bleeder valve and drain it out that way?
Putting the squeeze on brake calipers
- Thread starter AJB0009
- Start date
For front pistons I use a piece of wood or an old brake pad to slowly push the piston in using a C Clamp.
For the rears I use a disk brake tool which does the same thing only spins it at the same time.
Never cracked a bleeder for doing this.
For the rears I use a disk brake tool which does the same thing only spins it at the same time.
Never cracked a bleeder for doing this.
I usually use a turkey baster to suck as much brake fluid as I can from the Master cylinder, then compress the piston with a clamp or big slip joint pliers. Then suck out the rest of the fluid and replace.
But it's probably not the best practice and cracking a bleeder would keep the contaminants from the system.
But it's probably not the best practice and cracking a bleeder would keep the contaminants from the system.
I tend to always keep fairly clean fluid in my systems, so I just push them back in and bleed after to get any contaminants out.
Same here. If the fluid is changed somewhat regularly, I find this to be a non-issue.
I used to just push it back to the master cylinder, but with the advent of ABS and automatic braking I no longer take the chance of damaging the pump. Now I open the bleeder. A little bit of makeup fluid doesn't hurt, and I don't run the risk of either overflowing the master cyl, or getting air into the system.
I may be being overly cautious, but those are expensive parts.
I may be being overly cautious, but those are expensive parts.
I pull a little fluid out so it doesn't overfill, but then push it back.
Nowadays I do my brake fluid by just emptying/filling the reservoir periodically and never bleed. I find bleeding creates more risk of inducing air if you have already have a nice, air-free system. The partial drain/fill works - not instantly like with a transmission or PS system, but over time a little mixes in the MC and eventually you've reduced the water content by 1/2.
I did see evidence of this - someone used hygoscopic test strips and showed a continually reduction of H20 content on each drain/fill of the reservoir. 4% fell to 2% after the first change and some time, then to 1% after the 2nd drain/fill.
Nowadays I do my brake fluid by just emptying/filling the reservoir periodically and never bleed. I find bleeding creates more risk of inducing air if you have already have a nice, air-free system. The partial drain/fill works - not instantly like with a transmission or PS system, but over time a little mixes in the MC and eventually you've reduced the water content by 1/2.
I did see evidence of this - someone used hygoscopic test strips and showed a continually reduction of H20 content on each drain/fill of the reservoir. 4% fell to 2% after the first change and some time, then to 1% after the 2nd drain/fill.
gathermewool
Site Donor 2023
I keep the zirc closed while pushing the pistons back in. I bleed the brakes afterward.
Its very hard to introduce air into a location that’s lower than the reservoir. What you’re doing is better than nothing, I guess.
Anecdote: I did the first brake fluid change in our new-to-us ‘08 CiVic LX after around 60k miles and nasty black fluid was the first thing out of the rear drum zirc. The front fluid wasn’t black, but dark and opaque. I don’t think the “turkey-baster” method would have done anything to improve what was closest to the piston in that case...
Its very hard to introduce air into a location that’s lower than the reservoir. What you’re doing is better than nothing, I guess.
Anecdote: I did the first brake fluid change in our new-to-us ‘08 CiVic LX after around 60k miles and nasty black fluid was the first thing out of the rear drum zirc. The front fluid wasn’t black, but dark and opaque. I don’t think the “turkey-baster” method would have done anything to improve what was closest to the piston in that case...
Actually, it's REALLY easy to do that, from bleeding. The bleed screws (not actually zerks) will introduce air through the threads. It will get in the upper cavity of some pistons; the line is not always at the highest point. I see more air get into systems from amateur bleeding than from general use.
The drain/fill system is actually highly effective, definitely a lot more than "better than nothing."
gathermewool
Site Donor 2023
Actually, it's REALLY easy to do that, from bleeding. The bleed screws (not actually zerks) will introduce air through the threads. It will get in the upper cavity of some pistons; the line is not always at the highest point. I see more air get into systems from amateur bleeding than from general use.
The drain/fill system is actually highly effective, definitely a lot more than "better than nothing."
Just sharing my life-changing experience with the Civic. I’ll never be convinced that a reservoir baster method is good enough. Better than those who never service the brake fluid? Sure. As good as a proper flush? No way!
I’m not understanding your logic. The reservoir is the high point, so why would air be introduced? Regardless of whether the line to the caliper angles up or down, gravity will force flow from the high point, the reservoir, to the low point, the bleeder.
If you think you might have pumped air into the system by pushing the zirc in, just crack it and wait for fluid and air to dribble out.
My suction bleeder broke before (WHILE bleeding the brakes) and I was left gravity bleeding all of them. Worked like a charm!
I squeeze the piston back, then bleed with with a speed bleeder.
Never say always but I typically open the bleeders before pressing the pistons in.
I crack the bleeder, it makes it easier to push the piston back and prevent sludge and junk going up into the ABS filters. When I do a brake job I replace the fluid anyway so its good to get the old stuff out at the wheel.
Some may find this interesting.
Preventing Damage to ABS Modulators During Brake Pad Replacement - Phoenix Systems
www.brakebleeder.com
Edit: I forgot to mention by cracking the bleeder makes it much easier to detect a sticking caliper piston.
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I think that most folks just push the fluid back to master cylinder and turkey baste it out. However, the right answer is to bleed it through the bleed screw. The reluctance to do that comes from the types of problems you might get from the bleed screw if the caliper housing is badly rusted, from not being able to get the screw to re-seal to snapping it off in its housing. Opening the bleed screw elevates the risk a step. From a simple pad replacement you might now be looking at several other headaches. Also, did you remember to tighten it enough, because if it leaks, no brakes.
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Typically I just use the pad I'm replacing to push the piston back in. My cars have always had a single piston though.
The Giulia comes with a 4 piston caliper and I don't think that's going to work anymore. If anyone has good experiences with a spreader for a 4 piston set-up, please share as I'm in the market for one.
The Giulia comes with a 4 piston caliper and I don't think that's going to work anymore. If anyone has good experiences with a spreader for a 4 piston set-up, please share as I'm in the market for one.
I open the brake reservoir to avoid any unwanted back pressure and use a C clamp to push the piston back into the caliper. Sometimes this is easier with the pad in place, especially if it's more than a single piston caliper.
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I crack the bleeder, it makes it easier to push the piston back and prevent sludge and junk going up into the ABS filters. When I do a brake job I replace the fluid anyway so its good to get the old stuff out at the wheel.
Some may find this interesting.
Preventing Damage to ABS Modulators During Brake Pad Replacement - Phoenix Systems
Edit: I forgot to mention by cracking the bleeder makes it much easier to detect a sticking caliper piston.
Thanks Trav, I've been doing it wrong. I've been using a pry bar on the pads (I'm going to replace anyway) to force the piston back in so the new pads will fit. I WASN'T accounting for the ABS module. I will now use plastic hose pincher pliers and crack the speed bleeder prior to pushing the piston(s) back in. I also regularly bleed the entire system.
