i just flushed the brake fluid of my 88 supra n/a today. it was very dirty before the flush, that's why i did it. i had tried looking for the correct sequence, but there were many different suggestions online. in the end i chose to follow the "do the furthest from master cylinder first" rule, which was in this order: RR-RL-FR-FL.
the problem came when bleeding the 3rd brake, which was FR. my wife (who did the stepping on the brake for me) told me that the brake seemed to become "soft", which meant air got trapped. so i went to check the reservoir. it was low but not empty (i always kept an eye on it and already topped it off couple times before this). so i topped it off again, and continued bleeding FR.
there was some air flushed out shortly after that, i kept bleeding it until no more air out. but the brake was still soft. so i bled FR again for many more times but still no air came out. so i went on bleeding the last brake, which was FL, and hoped that would flushed the remaining air out. but to my surprise no air came out of FL no matter how many times i bled it.
so i had to check the rear brakes again and found the air was trapped in RL. after flushing all the air out of it, my wife told me the brake had become "hard" again. i double checked it, and it seemed to be all good now. but i wanted to bleed the other ones again just to make sure no more air trapped in the system.
that was when this strange problem came in. as soon as i started bleeding FR, my wife told me the brake became "soft" again! but there was no air came out of it no matter how many times i bled it. so i went straight to RL and found lots of air trapped there again! i had to bleed it like more than 20 times in order to flush all the air out. the brake seemed to be working properly after that.
i'd like to confirm this pattern but i don't want to mess with it again, because it'd take lots of work (i had to take the wheel off in order to access the bleeder behind it) and it'd be wasting more brake fluid (i already used two 32oz bottles because of the air problem). but why bleeding FR would cause the air to be trapped in RL? the reservoir was never empty during the flush. would it mean there's some hidden problems with the brake system? maybe brake line leak or something? but i've checked, it seemed to have no leak. i started up the car and stepped on the brake really hard for many times. i also did a road test, and the brake seemed to be working fine. but it was just a short test. i don't want to have a hidden problem that would cause the brake to fail later and kill me on a freeway.
sorry for the long post. i just want to write it up as detailed as possible so that everyone knows what happened exactly. and hopefully someone would give me a peace of mind or at least some idea on what to shoot for. thanks!
the problem came when bleeding the 3rd brake, which was FR. my wife (who did the stepping on the brake for me) told me that the brake seemed to become "soft", which meant air got trapped. so i went to check the reservoir. it was low but not empty (i always kept an eye on it and already topped it off couple times before this). so i topped it off again, and continued bleeding FR.
there was some air flushed out shortly after that, i kept bleeding it until no more air out. but the brake was still soft. so i bled FR again for many more times but still no air came out. so i went on bleeding the last brake, which was FL, and hoped that would flushed the remaining air out. but to my surprise no air came out of FL no matter how many times i bled it.
so i had to check the rear brakes again and found the air was trapped in RL. after flushing all the air out of it, my wife told me the brake had become "hard" again. i double checked it, and it seemed to be all good now. but i wanted to bleed the other ones again just to make sure no more air trapped in the system.
that was when this strange problem came in. as soon as i started bleeding FR, my wife told me the brake became "soft" again! but there was no air came out of it no matter how many times i bled it. so i went straight to RL and found lots of air trapped there again! i had to bleed it like more than 20 times in order to flush all the air out. the brake seemed to be working properly after that.
i'd like to confirm this pattern but i don't want to mess with it again, because it'd take lots of work (i had to take the wheel off in order to access the bleeder behind it) and it'd be wasting more brake fluid (i already used two 32oz bottles because of the air problem). but why bleeding FR would cause the air to be trapped in RL? the reservoir was never empty during the flush. would it mean there's some hidden problems with the brake system? maybe brake line leak or something? but i've checked, it seemed to have no leak. i started up the car and stepped on the brake really hard for many times. i also did a road test, and the brake seemed to be working fine. but it was just a short test. i don't want to have a hidden problem that would cause the brake to fail later and kill me on a freeway.
sorry for the long post. i just want to write it up as detailed as possible so that everyone knows what happened exactly. and hopefully someone would give me a peace of mind or at least some idea on what to shoot for. thanks!
