brake flush problem

maybe air got into your master cylinder...
Click to expand...
How do I do this? Any help much appreciated!
Click to expand...

you bleed the master cylinder the same way as you bleed the calipers...


this may get a little messy..so keep rags near by and cover as much of the hood area possible from getting brake fluid on paint and floor..

have someone pump the brakes a few times..while "holding" the brake pedal down.. crack the master cylinder/brake line fitting..
the fluid will come out along with any air..repeat as many times as necessary and a couple more times just to be safe...

wash off all brake fluid that sprayed and/or dripped down from car..



or you get some fittings hoses attached them...

detach the brake lines from the master cylinder and attach special fitting with hoses...bend the hoses back up to the reservoir so that the hoses are submerged in brake fluid...in this case all you have to do is pump the brake..you will be able to see the bubbles come out...

Note: this method you may be required to pull the brake lines out to attach the fittings in...it maybe a little difficult to re attack the brake line afterwards

this method is the same as "bench bleeding" the master cylinder..


then bleed all 4 calipers..


NOTE: I have never bled the master cylinder on a NSX before but I have bled the master cylinder on many other cars before that had similar symptoms or if I had to replace the master cylinder..

If anyone has bled the master cylinder on a NSX please correct me if I am mistaken on this procedure for a NSX..
 
matteni,

If all the brake fluid was drained out, most likely you have air in the master cylinder. You need to prime (or bleed) the master cylinder but I've never primed an installed master cylinder and don't know if it can be done. You should also get the speedbleeder. I've bled my brake with powerbleeder, vacuum pump and speedbleeder, and there is no substitute for speedbleeder.

HAND
 
Taj said:
matteni,

If all the brake fluid was drained out, most likely you have air in the master cylinder. You need to prime (or bleed) the master cylinder but I've never primed an installed master cylinder and don't know if it can be done. You should also get the speedbleeder. I've bled my brake with powerbleeder, vacuum pump and speedbleeder, and there is no substitute for speedbleeder.

HAND
Click to expand...

I have had Speedbleeders on all 4 wheels and the clutch for over 5 years - love them!

I got a great tip from Larry B. the master.
He said to:

- try again and pump very slowly,
- never lower then you would normally press the brake,
- only untighten the screw a little to create some back pressure
- and then tighten and tap on the calliper with a hammer to free up some of the air and bleed again

Patience grasshopper
Click to expand...

yes master!

:)
 
Since air is lighter than oil, the airbells want to go to the highest point. In aviation we are no longer bleeding the brakes by pumping the pedal, but by pushing oil up from the brake to the pedal. Isn't this possible with the X?
 
Re: brake flushing problem

Located this old thread. Didn't want to Dup.

Last night we just put on brake calipers on the NSX. They have been off for several days. After continuous pumping on the breaks to bleed, the pedal get's harder and tighter. We bleed a few times on each caliper. However, once we started the car, the breaks would feel a little mushy, pressure is not as tight and pedal would go down further than normal. While driving the car, when we pump the breaks a few times, the pressure builts up again and feels better. After a several mins of driving again, we would have to pump the brakes a few times to built pressure again.

We check the master cylinder and slave, no apparent leaking, brake fluid is full.
We had to take the tires off for a second bleeding. Still same issues.

I was thinking to just take it to the local Honda Dealership and have them check it out and do a complete flush on the brakes and check master cylinder. The local Acura Dealership is 25 mins away. Too far considering my brake conditions.

Anyone recently experience the same problems? Any suggestions??
 
do those vacuum bleeders work correctly?
i tried to use one (craftsman) on my clutch slave..... and all i got was air bubbles the whole time. did it the traditional method and i was on my way in a couple pumps of the pedal.
is there a reason why it would work better for the brakes?
all i know is i'm going to bleed them the traditional way from now on
 
Rebleed for sure. Vacuum bleeder certainly work, and will save you brake master cylinder. When you bled the brakes did you pump the pedal and have it travel to the floor, then repeat?

If after more bleeding it does not firm up, you will probably need a new brake master cylinder.

Regards,
LarryB
 
Larry Bastanza said:
Rebleed for sure. Vacuum bleeder certainly work, and will save you brake master cylinder. When you bled the brakes did you pump the pedal and have it travel to the floor, then repeat?

If after more bleeding it does not firm up, you will probably need a new brake master cylinder.

Regards,
LarryB
Click to expand...

Thanks for the info. I'll try bleeding it again, but prior to changing brakes I did not have this problem with the Master Cylinder. I hope it's just air in the lines. If not does anyone have any recommendations where I can get a new M.C.? Besides the dealership?
 
When you bled the brakes did you pump the pedal and have it travel to the floor, then repeat?

You did not answer my question:).

Brake Master, dealer only, no seals available separately.

Regards,
LarryB
 
Larry Bastanza said:
When you bled the brakes did you pump the pedal and have it travel to the floor, then repeat?

You did not answer my question:).

Brake Master, dealer only, no seals available separately.

Regards,
LarryB
Click to expand...

What I did was I pumped the brakes 5x and on the 6th pump, I floored it. We did this process only 2 times on each caliper. I have a feeling that it still has air in the lines for the following reasons:

1. I had the car on jack stands with all 4 calipers off for a week. I sealed off each brake line with a latex finger part of the glove and zip ties. Each of the lines did have some driping.

2, Master Cylinder never had any issues prior to changing brakes/rotors/calipers.

BTW: what's the current price of a Master Cylinder? Just in case.
 
I don't track my car, and so I only flush the brake fluid every 2 or 3 years. But, in that simple process - brakes working fine when I start and pedal being firm when I finish - I use a full quart of fluid. So I'm not sure how 16 oz would fill a dry system. My wife gets the "pump the pedal" duty, and we usually do about 8 to 10 full pumps to the floor (close the bleeder each time the pedal is let up) per caliper and follow the order in the manual as Larry stressed.

I also followed the NSX-Prime write-up on flushing the ABS without the ABS bleeder tool. Again, I maybe overdid it -- I used a whole quart of fluid just for that. I exercised each of the four solenoids multiple times. I've owned the car since 2000, and this was the first time I did the full ABS flush routine. Before that I simply did the turkey-baster thing and changed the fluid in the reservoir. My ABS used to do its 20 seconds of clacking when I did a hard stop at the bottom of my steep driveway after the car sat for about two weeks. After the flush, I've never heard it clack again. And the ABS definitely works, as tested by making that hard stop in my driveway littered with the Fall leaves.

Frank
'96 NSX-T, red/tan
 
If Honda's ABS is like all others, you'll need to get the proper tool/scan tool to activate the ABS valves and solenoids.. IF air gets in BEHIND or on the other side you can bleed all you want, but the air is trapped on the "other" side of the ABS circuit....

Typically, on just about every ABS unit you'll have to cycle the ABS pump/valves to free up air. As carefull as you may have been, there is a chance that you allowed air into the ABS valves. Some bleeders can force fluid past the valves. I'd check with a good Honda tech to ensure that you don't need to electrically open or cycle the valves to get the air out.


again, just my two cents worth..

ACD
 
Problem solved! I just decided to flush the brake fluid out 100 percent. I just used a blue colored DOT 4 racing brake fluid. I just kept pumping out the old fluid on each caliper until the fluid turned completely blue using a clear hose connecting to the bleeder.
 
i hate to beat a dead horse, but i am putting my calipers back on after a rebuild (and full drain of the brake system). i have run about 1.5 bottles of motul through the system, but i am still on the first damn caliper (R RR). i tried to close that one, and go through the proper bleeding sequence (to ensure that all the calipers at least had fluid running through them); however, when returning to the R RR, i still have bubbles. sometimes it will be clear for a pump or two, but then there is a "train" of bubbles:frown:
also, i noticed every once in a while, when pushing the pedal down, there is a "squeak"-type noise coming from the front.... i'm guessing the master? either way, i haven't pushed the pedal all the way down (only till its right next to the gas pedal). i've never had any problems with the master, should this be something to worry about?

any help with this? how much fluid should i expect to go through? if/when i do finally get the R RR caliper to stop bubbling, will i have the same crappy problem with the rest of them??? that's a LOT of fluid.

does tapping the calipers with a mallet really help? if so..... is it effective enough for me to not have to bleed 1/2 a gallon of brake fluid through the system? i really don't want to have to re-bleed the system after i put the car back on the ground (i'm so sick of having my car up!)

i duno, it just seems like when i bleed stuff it takes WAY more fluid than anybody else..... just for the record - i thoroughly hate bleeding hydraulics. :mad:
 
did you ever bleed the HCU / ABS valves??? As I mentioned if you get air inside the valves,, you'll be there a year trying to bleed it out your way.. Typically, this should have triggered an ABS code...but may not have.

Be aware that this unit is under pressure from the accumulator, i believe it has it's own bleed valve.. Lastly, with as many nooks, valves and hiding places for air in an ABS a pressure bleeder or even a vacula is a much better method then the pumping the snot out of your master cyl method


Just a thought....
 
ACCD said:
did you ever bleed the HCU / ABS valves??? As I mentioned if you get air inside the valves,, you'll be there a year trying to bleed it out your way.. Typically, this should have triggered an ABS code...but may not have.

Be aware that this unit is under pressure from the accumulator, i believe it has it's own bleed valve.. Lastly, with as many nooks, valves and hiding places for air in an ABS a pressure bleeder or even a vacula is a much better method then the pumping the snot out of your master cyl method

Just a thought....
Click to expand...

i thought the abs was on a "separate system". isn't the fluid isolated from the master cyl? and why would it matter if i pumped the master cyl to bleed?
 
It's a seperate system in the sense that it will isolate the pedal from the driver under ABS conditions, not allowing more pressure to be added. the ABS itself is part of the "brake system" which shares fluid and manages fluid flow in the modulated valving portion of the ABS. These valves are designed to isolate, hold and release pressure to your brakes as needed. hence using the same brake fluid in the system. Yes you do see two reservoirs, but they're managing the same fluid. The ABS reservoir is there to manage fluid during the ABS cycle. Without this your peddle would pulsate back at you. But the two are "integrated" components. It's when you get air into that "second side" the ABS side that you run into challenges in getting the air out of all the valves.

It may be worth a trip to the dealer and have them pressure bleed it, and use the proper scan tool to cycle the valves.


See what others have to say.
 
thanks for taking the time to explain; looks like i need to do some more reading on the abs system :wink:

in any case - would a drain of the primary brake hydraulics cause air pockets in the abs unit? why hasn't anybody else mentioned this as being a concern?
 
it could have caused air.. the issue is that the abs is "split" and all it would take is a minor fault, stick valve,, etc.. etc. for air to get trapped on the "other" side of the modulator valves.
It's been a while since I've worked on ABS units, however in my previous life I spent 14 years with a company called Raybestos and certified techs on ABS as they became available in the mid to late 90's.. Now I just try to take money from attorneys:) Not saying I have the right answers, but with the issues / frustration that you've been going through, it's worth a look. Good luck.

keep us posted
 
Synthesis said:
thanks for taking the time to explain; looks like i need to do some more reading on the abs system :wink:

in any case - would a drain of the primary brake hydraulics cause air pockets in the abs unit? why hasn't anybody else mentioned this as being a concern?
Click to expand...

From your first comment, I was not clear on whether you replaced all of the calipers or just the right rear?

When you close the bleed nipple on the caliper you just replaced and pump the brake pedal, does it firm up and stay firm? I had problem with one of the bleeder nipple being a little too loose(the teflon around the thread was worn) and letting air in right at the base of the bleeder which would come out in the form of bubbles. Might want to check for that.
 
ak said:
From your first comment, I was not clear on whether you replaced all of the calipers or just the right rear?

When you close the bleed nipple on the caliper you just replaced and pump the brake pedal, does it firm up and stay firm? I had problem with one of the bleeder nipple being a little too loose(the teflon around the thread was worn) and letting air in right at the base of the bleeder which would come out in the form of bubbles. Might want to check for that.
Click to expand...

some clarification - i rebuilt my front calipers and replaced all the hoses with SS lines. when i removed the calipers i just let the fluid do its thing and drain out. so, before i started the bleeding process, the master and everything else was empty (except maybe the RR calipers).

as far as i know, the pedal was firm, and did not drop to the floor. (i was the guy opening and closing the bleeders. i didn't bleed the master, but with this much fluid, i should expect any air up there to be gone, no?

i guess i will try again, being more aware of how much i am opening the bleeders..... maybe i was opening them too much each time? (i was opening them 1/2 to 3/4 turn each time yesterday..... )
 

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