I am like @oldtimer-11 when it comes to brakes. Adding brake fluid every time the level drops slightly below the max is akin to adding oil to the engine an ounce at a time every time the level drops below the top line on the dipstick.
But as I said before, your car, your decision.
Thereās a difference though. Engine oil drops itās because itās either burned or leaked or evaporated away. But when brake fluid drops most likely itās because the pads are wearing down. Replace pads without bleeding the brakes will bring the brake fluid level back up because you pushed the piston back in and forced the fluid back into the line. I donāt recommend doing it that way.
I donāt either.
do folks replace brake pads without breaking the system open? Is that what the owners manuals up above are suggesting?
Iāve seriously never heard of proās (or anyone that cares about the safety of their passengers,) doing it this way. Changing pads is a perfect time to do a brake fluid flush.
Depends on which car Iām working on. My non-ABS-equipped cars, sure. The ones with ABS, Iāll crack the bleeder when Iām compressing the piston. Thereās usually not enough fluid loss from this procedure to bring the reservoir very far below max at all.
I donāt always exchange fluid on pad changes because itās not necessary. If Iāve done a lot of track days with the fun car, I might need new front pads within months of their last replacement. Nothing wrong with the fluid at that point, so thereās no need for a full flush.
I donāt. I open the bleeder valve when I push the piston back in. You can damage the ABS sensors on modern vehicles if you donāt.
On my non-ABS car, I just pop the top off the master cylinder before compressing the caliper, but after reading this discussion, I think Iāll farm out brake jobs for any vehicle that has ABS rather than try to bleed the brake line while doing a pad replacement.
As long as you open the bleeder valve itās not a problem.
Iām going to flush and bleed every time I do a pad replacement whether ABS or not. Itās not that hard to do.
Bleeding brake lines is something Iāve messed up in the past and had to farm out, just like gaskets. I stick to what Iām good at, which is basic maintenance and very basic repairs, like a belt or an alternator. Anything more complicated than that Iām happy to pay someone else to do.
As long as it is above the minimum mark I think you are good.
Keep an eye on it in case there is a leak.
The 2012 Toyota I have had since new is the first car I have ever had that I could get the bleeder screws open on after it was 2 years old. Toyota did a very good job designing the rubber caps for the bleeder screws. They are still shiny when you take the caps off.
My 2004 PT Cruiser, the bleeder screws were not the only things rusted into immobility. When it was 3 years old I decided to take the back drums off to check the brakes. I could not get the drums off. The star wheel adjuster was frozen tight I had used penetrating oil around the studs and center hole and used a small screwdriver to lift the locking tab but the adjuster would just not move. I decided to deal with it when the rear brakes started grinding but at 7 1/2 years some idiot on his cell phone totaled it so I never get the drums off. I would have had to grind the heads off the two shoe mounting pins where they go through the backing plate and force drums shoes and hardware all off at once.
Interesting thread. Iāve never really considered using the brake fluid reservoir as a gauge for pad wear. It makes sense, of course. Iāve just always visually inspected pads and left the reservoir pretty much alone unless it was close to the min mark, which usually led to me finding a leaking wheel cylinder or something.
Iāve also never cracked a bleeder when changing pads. I just push the piston into the bore. I suppose thatās the way I learned to do it. Iāve done brakes for so longā¦that I honestly donāt remember where or how I learned to do them. Iāve never had any problems doing it that way. But I think Iāll crack the bleeder screw next time. Makes sense that you could force some old brake fluid goo backwards into a place it doesnāt need to be by pushing the piston. Of course, if youāre religious about fluid flushes, youāll have no goo. Iāll admit, Iām not a frequent flusher. Probably should be, but I tend to be lazy in that area.
Opening the bleeder when compressing the caliper pistons can save a lot of grief on ABS brakes and doing so seems to greatly increase the life of the calipers.
Understood, plan to go that route in the future. I donāt remember where I originally learned to change pads, but I assume they pushed the piston in without opening the bleeder. Kind of interesting that I donāt remember where I learned to do a brake job! I remember bleeding the brakes on a 1950 Chevrolet truck with my dad when I was maybe 10 or 12. I believe the master cylinder was under the floorboard. Thatās the first brake related work I can recall.
I assume the first pad replacement was on one of my old Jeeps. But I do not remember doing it or who instructed me, or if I just flew by the seat of my pants.
Regardless, opening the bleeder would probably be the way to go, so Iāve learned something.
I vaguely remember that they recalled PT Cruisers for abnormally-rusting brakes, but specifically excluded certain states in the rust belt because they didnāt feel like spending more money.