Soft brake pedal
10-11-20, 06:20 PM
#1
Pit Crew
Thread Starter
Soft brake pedal
I feel like I've done almost everything, and yet, the brake pedal remains soft no matter what. Can't seem to get it firm. I have a 2001 ES300 and in the past 2 years of ownership, I can't seem to get a firm brake pedal.
In the first 6 months or so I took it to my mechanic a handful of times, and after they replaced the master the 2nd time (first part was defective), they insisted that there was nothing wrong with the system or brake lines, and they just bled it over again and it went firmer. Every time I'd get it back, it was firm for a day or two, then it went back to being soft. Had them check over the lines for any corrosion, weren't able to find anything.
The past year or so, I've done the following myself:
- Replaced both front calipers with dual-piston 96 ES300 calipers (re-manufactured Raybestos)
- Replaced both rear calipers (just yesterday) with re-manufactured PowerStop calipers
- Replaced all 4 rotors and pads twice (first set i replaced in Nov 2018 and they were not very good quality, now have Centric rotors and Akebono pads - no complaints there)
- Ensured all slider pins are probably greased (using AGS Syl-Glyde, aka the good stuff that doesn't swell the rubber)
- Bled the system probably a good 10-15 times (over a year) I've tried regular bleeding, vacuum pump bleeding, even gravity bled. Even went ahead and got the ABS to engage a bunch during the winter to try to cycle the fluid.
About 6 months ago, I replaced the front calipers with the upgraded dual piston calipers, and that seemed to make the pedal quite a bit firmer, and I was pretty content with it. However, just about a month ago I noticed that one of the rear calipers piston was starting to seize up a bit, so I went ahead and ordered replacements for both sides.
I replaced both calipers yesterday, everything went fine, and bled the system using the regular 2 person bleeding setup. Took it out for a test drive and the pedal was much softer than before. I actually immediately noticed the pedal being much "weaker" when I held down the brake pedal normally and shifted to reverse and it didn't hold the car in place very well.
Today, I bled it again, there was a little bit of air left over (very small amounts), and after test driving it, it seems like it got marginally better. The car brakes well (as in it slows down fine), I tested some harder brake tests, and it stopped well, but I didn't go hard enough to engage the ABS this time around. However, the pedal is still pretty soft. It still doesn't hold the car in place very well when I shift to reverse while still holding down the pedal, and the pedal itself it remarkably soft when the car is park and I press down (very little feedback). While driving, it's still much soft than before when there was a slightly seized up rear caliper.
Is it possible there's something wrong with the replacement calipers, how could I test that?
Is there anything else I might have missed? Does it need to be taken a Toyota/Lexus dealer to get the ABS system checked-out/bled?
The only thing I haven't really replaced is the ABS module (expensive, unless I buy used off ebay) and the Brake booster. However the latter seems fine, and from what I remember when the brake booster went out on one of my other cars, the pedal became pretty hard to press rather than soft. However that wasn't a Toyota/Lexus, so maybe it's different in this case.
Anyone have any clue what the issue might be? It's driving me crazy!
In the first 6 months or so I took it to my mechanic a handful of times, and after they replaced the master the 2nd time (first part was defective), they insisted that there was nothing wrong with the system or brake lines, and they just bled it over again and it went firmer. Every time I'd get it back, it was firm for a day or two, then it went back to being soft. Had them check over the lines for any corrosion, weren't able to find anything.
The past year or so, I've done the following myself:
- Replaced both front calipers with dual-piston 96 ES300 calipers (re-manufactured Raybestos)
- Replaced both rear calipers (just yesterday) with re-manufactured PowerStop calipers
- Replaced all 4 rotors and pads twice (first set i replaced in Nov 2018 and they were not very good quality, now have Centric rotors and Akebono pads - no complaints there)
- Ensured all slider pins are probably greased (using AGS Syl-Glyde, aka the good stuff that doesn't swell the rubber)
- Bled the system probably a good 10-15 times (over a year) I've tried regular bleeding, vacuum pump bleeding, even gravity bled. Even went ahead and got the ABS to engage a bunch during the winter to try to cycle the fluid.
About 6 months ago, I replaced the front calipers with the upgraded dual piston calipers, and that seemed to make the pedal quite a bit firmer, and I was pretty content with it. However, just about a month ago I noticed that one of the rear calipers piston was starting to seize up a bit, so I went ahead and ordered replacements for both sides.
I replaced both calipers yesterday, everything went fine, and bled the system using the regular 2 person bleeding setup. Took it out for a test drive and the pedal was much softer than before. I actually immediately noticed the pedal being much "weaker" when I held down the brake pedal normally and shifted to reverse and it didn't hold the car in place very well.
Today, I bled it again, there was a little bit of air left over (very small amounts), and after test driving it, it seems like it got marginally better. The car brakes well (as in it slows down fine), I tested some harder brake tests, and it stopped well, but I didn't go hard enough to engage the ABS this time around. However, the pedal is still pretty soft. It still doesn't hold the car in place very well when I shift to reverse while still holding down the pedal, and the pedal itself it remarkably soft when the car is park and I press down (very little feedback). While driving, it's still much soft than before when there was a slightly seized up rear caliper.
Is it possible there's something wrong with the replacement calipers, how could I test that?
Is there anything else I might have missed? Does it need to be taken a Toyota/Lexus dealer to get the ABS system checked-out/bled?
The only thing I haven't really replaced is the ABS module (expensive, unless I buy used off ebay) and the Brake booster. However the latter seems fine, and from what I remember when the brake booster went out on one of my other cars, the pedal became pretty hard to press rather than soft. However that wasn't a Toyota/Lexus, so maybe it's different in this case.
Anyone have any clue what the issue might be? It's driving me crazy!
10-11-20, 09:54 PM
#2
Lexus Fanatic
You 100% sure there are no leaks? I'm betting the answer is yes but I have to ask.
I've never got good results with vacuum bleeders in fact it made the problem worse, two person method is best. Bleeder open - pedal to floor - bleeder closed - release pedal. I've also never had to do anything special to get air out of the ABS pump even in a system that went completely dry. I don't know what else you can try, do you have an OEM part in for the master cylinder?
One thing that can cause odd problems is a brake hose that is collapsed internally, never had this happen myself but read about it, it makes bleeding difficult or impossible and the pedal feel can go soft or be normal. Only thing is on these cars they are not known to go bad. Another thing I've read about is the brake booster went bad and caused issues like spongy pedal feel.
I've had bad luck with reman calipers I only do them myself now.
I've never got good results with vacuum bleeders in fact it made the problem worse, two person method is best. Bleeder open - pedal to floor - bleeder closed - release pedal. I've also never had to do anything special to get air out of the ABS pump even in a system that went completely dry. I don't know what else you can try, do you have an OEM part in for the master cylinder?
One thing that can cause odd problems is a brake hose that is collapsed internally, never had this happen myself but read about it, it makes bleeding difficult or impossible and the pedal feel can go soft or be normal. Only thing is on these cars they are not known to go bad. Another thing I've read about is the brake booster went bad and caused issues like spongy pedal feel.
I've had bad luck with reman calipers I only do them myself now.
10-11-20, 10:25 PM
#3
Pit Crew
Thread Starter
In terms of leaks, I can't be 100% sure, but I've tried checking over visible portions of the lines myself and found nothing, and my mechanic noted there was nothing either. That was about a year ago, since then I've been really paying attention to the master cylinder level and I haven't noticed it really go down at all. The level hasn't gone down, but I've noticed the fluid becomes a bit darker over time, it doesn't go black or anything but its a light-medium brownish color. Could that indicate that there's a leak somewhere that's bringing air in, or more of just dirty fluid (which would be strange given how many times I've bled the damn system). Any suggestions on how to check for leaks effectively?
For bleeding, I also gave up on using a vacuum bleeder a while ago. Could never get the fitting on right, so it would just pull air from around the bleeder and not much else. What I've been doing is having the pedal pumped 5-6 times then held down, crack open the bleeder while connected to tube/bottle, then closing, and releasing pedal. Repeating until I no longer any air bubbles. Anything wrong with this technique?
I currently do not have an OEM master cylinder in there, I believe it's a Cardone A1 part. I know it's not the best but what happened at the time was that we suspected it was the original master that was gone bad, so I bought a Beck and Arnley replacement off RockAuto that was made in Japan (I assume this was just a reboxed OEM) but my mechanic tried it at the time and said it must have been defective and the only other part available locally that I could pick up as a replacement was a Cardone one from a parts store, so I had to go with it.
There was a decent period of time where it was fine (about the past 6 months before replacing the rear calipers) so I'm not totally sure if its the cause, but I suppose its worth a shot if nothing else works. I actually still have the original master cylinder, and even the beck and arnley one, so theoretically I could try one of them to see if the problem still occurs. I think RockAuto even sells the Advics one, which I think actually is the OEM for this car's master cylinder.
I'll try testing the brake booster again tomorrow morning to see if there's an issue with it (Hopefully not since they're $$$), but otherwise I'm beginning to become more skeptical of this Cardone master cylinder the more I type out this reply. Might be worth giving a shot at that Beck and Arnley master cylinder again...just dreading having to bleed the whole system again for the 3rd time in 2 days.
For bleeding, I also gave up on using a vacuum bleeder a while ago. Could never get the fitting on right, so it would just pull air from around the bleeder and not much else. What I've been doing is having the pedal pumped 5-6 times then held down, crack open the bleeder while connected to tube/bottle, then closing, and releasing pedal. Repeating until I no longer any air bubbles. Anything wrong with this technique?
I currently do not have an OEM master cylinder in there, I believe it's a Cardone A1 part. I know it's not the best but what happened at the time was that we suspected it was the original master that was gone bad, so I bought a Beck and Arnley replacement off RockAuto that was made in Japan (I assume this was just a reboxed OEM) but my mechanic tried it at the time and said it must have been defective and the only other part available locally that I could pick up as a replacement was a Cardone one from a parts store, so I had to go with it.
There was a decent period of time where it was fine (about the past 6 months before replacing the rear calipers) so I'm not totally sure if its the cause, but I suppose its worth a shot if nothing else works. I actually still have the original master cylinder, and even the beck and arnley one, so theoretically I could try one of them to see if the problem still occurs. I think RockAuto even sells the Advics one, which I think actually is the OEM for this car's master cylinder.
I'll try testing the brake booster again tomorrow morning to see if there's an issue with it (Hopefully not since they're $$$), but otherwise I'm beginning to become more skeptical of this Cardone master cylinder the more I type out this reply. Might be worth giving a shot at that Beck and Arnley master cylinder again...just dreading having to bleed the whole system again for the 3rd time in 2 days.
10-11-20, 10:34 PM
#4
Lexus Fanatic
For bleeding, I also gave up on using a vacuum bleeder a while ago. Could never get the fitting on right, so it would just pull air from around the bleeder and not much else. What I've been doing is having the pedal pumped 5-6 times then held down, crack open the bleeder while connected to tube/bottle, then closing, and releasing pedal. Repeating until I no longer any air bubbles. Anything wrong with this technique?
Beck/Arnley makes absolutely nothing they rebox as you found out it could be OEM or a piece of junk. The box of chocolates parts vendor. You should get an OEM master cylinder in there. The fluid should not be turning dark that quickly tells me the fluid is not being bled out effectively. About 50 pedal reps fills a quart jar about half way in my experience.
Use a piece of Toyota vacuum line it fits tightly over the bleeder.
10-11-20, 10:44 PM
#5
Pit Crew
Thread Starter
Interesting, guess you learn something new everyday! I think I've been using that technique for a good 15 years because that's what my dad had taught me. Definitely going to try the bleeding procedure you outlined tomorrow. Wonder if I've just been bleeding it wrong that whole time 
Maybe that's why none of our cars had firm brake pedals when I was growing up...
Maybe that's why none of our cars had firm brake pedals when I was growing up...
10-11-20, 11:09 PM
#6
Lexus Fanatic
I use the same method when I'm the only one doing it it (except bleeder stays open) works but takes longer. Don't pump the pedal fast, go slow say 3-4 seconds to get to the floor. Some will say never, never press the pedal all the way to the floor I always do, not massive force but I use the full travel.
10-12-20, 08:16 PM
#7
Pit Crew
Thread Starter
So I was able to get a much firmer brake pedal today after some bleeding.
First thing I did was bleed the master cylinder while it was in the car. Bit of a pain in the ***, since it was really hard to get one of the lines back on, but I eventually managed to after I removed half the intake air box.
Next, I went ahead and did the bleeding method you mentioned. Seems much better, was able to get a decent amount of air out of the first 3 calipers, then the most bubbles seemed to come out of the front driver side.
Took it out for a test drive, and much firmer pedal. Feel like there's a bit more firmness to be had, but I honestly don't know since I don't have another ES300 to compare to.
First thing I did was bleed the master cylinder while it was in the car. Bit of a pain in the ***, since it was really hard to get one of the lines back on, but I eventually managed to after I removed half the intake air box.
Next, I went ahead and did the bleeding method you mentioned. Seems much better, was able to get a decent amount of air out of the first 3 calipers, then the most bubbles seemed to come out of the front driver side.
Took it out for a test drive, and much firmer pedal. Feel like there's a bit more firmness to be had, but I honestly don't know since I don't have another ES300 to compare to.
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