Air in brake system

[SLCPUNK]

Ok, my brakes are driving me nuts. I got this car (86 Honda Accord dx) and the pedal was soft and the light comes on. I thought it was a faulty MC, since it went to the floor. I replaced MC (Yes I bench bled) and bled the entire system twice. I am still getting an air sound when I push the brakes and it travels to the floor. It stops the car, but slow and late.

I inspected the calipers: no cracking in rubber.

Inspected the rear wheel cylinders: no leaking or cracking.

Inspected all four rubbers hoses that attach to the calipers/wheel cylinders: They are hard and a maybe a little brittle, but no cracks.

Back right bleeder screw will not bleed out. Only dribble.

When I bleed the back left brake I constantly get air, so I assume that may be where my problem is. I got under the car but it seems that the line goes up into the frame? Do I need to take the back seat out to inspect the steel line?

Any thought would be greatly appreciated. Thanks.

[Dutchboy]

i think that the booster pushrod could be out of adjustment...
mabye when you took the old master off you screwed it up....

that may be why you get no pedal action and no response when drining...

try gravity bleeding the brakes too...
just open the bleedeer and let it dribble out for a bit if theres any bubbles coming out with the fluid...then do it by pumping the brakes and bleeding it.

BEn

[SLCPUNK]

How do I readjust that booster pushrod? If I take the MC off again, am I going to have to re-bench-bleed that thing again? Thanks

[Dutchboy]

yes you have to remove the master again to adjust it...
id get yourself a manual or see if theres any info on it at pauls website....you have to do it right otherwise it could screw up more.

if you take off the master cylinder again...just plug the hole once you take it off and put it down with the fluid resivior up of course....as long as the fluid doesnt drain all from it then it should be fine...
if you still have the bench bleeding kit it wouldnt hurt to redo it either to be sure..

BEn

[Dutchboy]

heres the site...
scroll down to the brake section and click the zip file...

http://www.pauldesign.ru/honda/shopmanual.html

Ben

[SLCPUNK]

Great thanks.

[Dutchboy]

Sure thing...
NOw im just being a post whore..
:lol :lol :lol :lol :lol :lol

BEn

[SLCPUNK]

Well crap. I remembered I can't open zip files for some reason. It always opens under Word and I can't figure it out. I had a couple of people help me with it, but we couldn't get it to work right. So I can't download the files. I could download, just not able to read them. Damn Damn.

Do you remember how to adjust the thing? Also, I noticed I have a slight change in idle when I press the pedal. Could this point to the Booster pushrod?

Now that you say it, I bet that is what it is. When I took off the old MC the pushrod came out with it. I had never seen it sticking like that, and thought it was odd.

An answer to this would probably pull you out of the "postwhore" category. Thanks dude.

[Dutchboy]

oh k that sucks .....ill grab my manual a sec then and see what you got to do...
What year is your car???
i dont think that theres a difference but the free play may be depending on model etc..

BEn

[anchovies]

I've read about a similar problem but with a different car. Gravity bleeding solved the issue.
Good luck.

[SLCPUNK]

The car is a 1986. How long do I gravity bleed? I've never done that before, what is the theory behind that? Thanks guys.

[Dutchboy]

yah the year doesnt make a difference...
Um gravity bleeding is just a easy way to rid off most of the air quicly...it just involes bleeding the system via gravity....the fluid in the master cylinder is higher than the brake cylinders so therefore the fluid will just run out on its own....just open one at a time,,,

bleed in this order,,,
rear passenger,, driver passenger,,,front passenger,,front drivers side

to do the pushrod clearance it says you need a special tool...mabye ill just downlaod the online manual...and paste the how to on this post. i dont feel like writing it out

DO your brakes work better when you pump them up at all??
there could be other factors to them not working but since you say it dribbles out when trying to bleed them by pumping them..then it seems like the master is at fault....it says to redo the pushrod when installing a new master too

Ben

[SLCPUNK]

It only dribbles out on the rear right wheel. The others are fine.

With the car OFF when I pump a couple of times it builds pressure and get a firm pedal. When I turn the car on, pedal does drop, but not to the floor, but almost. Seemed like normal booster operation to me.

I thought maybe a check valve, but I pulled it and it's ok.

I had a problem with the gasket at the end of the MC and the booster. Which I accidentally left on the old one. I put it back in and my problems got better. But I wonder if I could have put that gasket in backwards. It seemed to fit perfect the way it went in (Into the grooves of the MC end). It said M/P side this way. But that ened up facing the booster with that fit.

If you clip, that would be great. I have to get to the bottom of this tomorrow hopefully. I'm done with almost everything else and would like to sell the car.

[Dutchboy]

mmm.. the online manual doesnt have anything...and according to my manual..the only way to adjust the pushrod is by the back of the booster....
i guess it means from under the dash...you can adjust the star locknut closest to the firewall on the pedal rod....

but you say it pumps up so then i guess it isnt that and that theres alot of air in the lines or theres something else wrong...
if the back brakes are out of adjustment then the pedal will drop more than usual too...make sure there adjusted and bleed it again and see what happens/

BEn

[SLCPUNK]

I got another bleeder screw for the back right. I'll put that in, and rebleed that, adjust the back brakes (those pads are worn out-maybe that's it-but I can't imagine them causing that much of a problem), then gravity bleed and see what happens. Thanks for your help. I'll post what happens tomorrow night.

Jason

[SLCPUNK]

So I think I have the problem solved, almost...I need somebody to tell me if I'm right.

When I replaced the MC I forgot to put in the seal between the booster and the MC. So I was experiencing zero braking, and eratic idle. So I pop the seal in and idle is normal and brakes still poor. So...when I did this, did air enter back into the MC because the seal wasn't on? Can air enter the MC that way?

If that is the case, then I just have to re-bench-bleed that MC and I should be ok. When I drive it, it feels like a MC that hasn't been bench-bled and that is what made me think of it.

Does anybody know if the absence of the gasket (between the MC and booster) will allow air in the MC? Thanks again.

[Dutchboy]

it shouldnt becasue the master cylinder has seals in it which stop the air from entering in anywere....

id re bench bleed it and rebleed the system and see what happens.....
it could be a faulty master cylinder.

there must be air in there somewere....
first try bleeding it on the car though....do it like you would the calipers...just pump the brakes a couple times and lossen the line that goes into the master cylinder until it bubles out around the connection..
just dont get any fluid on your paint.

BEn

[SLCPUNK]

I replaced the calipers and they seem to be braking much firmer now. Still air though. I must have bled the car five times now.

So you are saying pump the brakes, THEN loosen the lines that go into the MC? Then once I see it bubble to close it up? I'd have to rebleed at the front and back then huh? Hahaha. Well hell. I'm done with everything else on the car, it does stop well. But it could stop better I suppose.

Take it easy Dutchboy. I'll tell you what happens once I'm done.

[Dutchboy]

how have you been bleeding the brakes???? mabye the technique you use is wrong..

you need to get someone to pump the brakes about 4 times and then hold it down hard..make sure that there foot is pressing down on the pedal as you open the screw
...open it for a few seconds..(air wont enter as long as the pedal is down)
you have to open the bleeder screw enough to...dont just crack it quick and close it ...open it and let the fluid rush out.
close the bleeder...not to tight and repeat if needed!!!!
....then after its done go to the next..

this is the same for the lines on the master cylinder...pump and open them up...fluid should rush around from the connection..
you got to make sure you open the bleeders enought to allow the air to escape...if you dont then it wont be able to get out..

BEn