Hi
I just replaced my mastercylinder since it took in air or something, and maked me to bleed the brakes almost every day. The calipers was newly rebuilt and had new hooses, and their was no leaks there either. So i replaced the masterC. and bench bleeded it in about 1 hour before the airbubbles stop coming up in the cylinder, then i installed it on the car, and bleeded the brakes as the instructions(But i cant find any metering valve on my car), and it still feels slobby as it did before i started this whole job.

And i still hear the Psst from the mastercylinder/booster? everytime i press the brake pedal. What did i do wrong?

No leaks or fluid dropping from the car.

And yes, forgot, when i open the filler cap the rubber diaphragm is poped out, why is it that? Its not like that for the reservoir for the rear brakes?

Please help...

Thanks

when air got into my system I had to break loose the conection to the rear brakes at the brake hose on the rear end. I don't know why I could not get it to bleed. I think the check valve was jammed up or something. This worked for me and i have not had problems since. One other thing I did do after this was a total brake fluid flush. It seemed to me if i was getting air from a bad master I was getting moisture also, which is a bad thing. Get a vacume tester to check your booster and see if it's leaking.

Good luck

Joe

Hi

I just started up the car and took a drive, the brakes start taking very low and then next time it feels like it takes much higher up.?

The pedal travels very loosly down almost to the floor and there it gets hard. Feels like it is a digital brake, On/Off.

[ 03-02-2003, 10:20 AM: Message edited by: MagnusRS68 ]

Right rear then left rear. Did a double take on mine today doing the right and left again after the first time around since I didn't trust the junction on top of the axle to not shift the bubbles bach and forth. You also have to bleed the front if you didn't since the front was cracked open for the master exchange. If there is one of those safety valves/propotioning valves below the master you have to trip it back the other wat by bleeding the opposite front or rear of what you did last.
Your symptoms are air in the fluid. Maybe crack the right rear bleeder with the master cap loose to let a gravity bleed go on for a while paying attention to the fluid level real good. Then start bleeding.

Thanks
I also heard that i might need to adjust the rearbrakes and center then, or what it was called.

I got some answers from other forums(swedish) and they said that they all had problems bleeding the 4 piston calipers, so they use a vacuum or a preassure bleeder. I guess they'll have the same effect. Suck/Press.

But does someone know about that rubber diaphragm? Mine is always poped out for the front brakes?

Thanks again

/Magnus

The diaphragm will move out as the fluid level drops to keep the fluid from splashing around and getting aerated. I suspect that you still have air in your system and as it is compressed the diaphragm pops out with the drop in fluid level.

I would get a vacuum bleeder (mighty vac) and try it on your calipers to get the air out. This equipment worked very well for me on my brakes!

Hey Snatch'gears,

Can you explain this proportioning with a safety again and this bleeding procedures?

Was this valve offered on a 67 maunal drum?

I bought a disk conversion kit and bench bled the MC, bleed the system numerous times using the "gravity bleeding","one man" method, "two men" method, and the vacuum method and still my brake pedal is soft.

No leaks were noted.

I change everything but the proportioning valve, so maybe this is my problem.

Thanks, :confused:

Thanks for the explaination of the rubber diaphragm. I got the resevoir filled and still it will pop out, and that must be caused by air in the system.

Gravity bleed? Whats that, is it when you fill the MC and opens all the bleeder screws and let the gravity do the rest?

If thats works, i then understand why i just have an upper bleeder screw on my calipers, everyone else i talked to here in Sweden says they got a lower and upper on their 4 piston calipers.

Im gonna test this gravity bleed.

Could anyone tell me the exact procedure todo this, please. =)

Many thanks

Sorry i cant give you any answer about the propotionvalve.

Russel makes excellent speed bleeders. They have a check valve inside the bleeder screw that keeps air from sucking back in when the pedal hits the floor. They make bleeding brakes sooooooooooo easy. I was a skeptic until I tried them . . . they're the best thing since sliced bread ;)

It took me 15 minutes to bleed my entire system after converting from drums to discs. I was almost dissapointed it was so easy.

ps. Did I tell you guys I like the Russel speed bleeders? LOL

Hi Eric68.

I had thoughts on buying 4 speedbleeders, but how do they work when you pump up the pressure? Or aint it nessesary to pump the pedal?

Im going to try to adjust the rear drums before i make a 3rd bleed test. I think those are the reason why my pedal travels about 2" before i feel any resistance.

And i also think i now know what that "Psst" sound comes from when i press the pedal. Because of the air the fluid level goes so low that i causes a vacuum in the resevoir(front) and it suck air in through that little hole on the MC cap. It must be like that, otherwise it wouldnt be possible to press the pedal(if it was totaly air tight there). And that air aint causing the air in the lines, but it explains the Psst. smile.gif

Another sleepless night. In reallity a brake system is so easy and logic, but i always tend to see it as a much more advanced thing when it comes to it.

Well, I just ordered a few sets of Russell speed bleeders for my camaro and GMC truck. Great topic.

When there was a LOT of air in my system I used the speed bleeders like regular bleeder screws --- I just pumped up the pedal then opened the screw. Later after I got most of the air out I just left the screws open about a half turn and slowly pushed the pedal down repeatedly, no need to pump and no need to tighten the screw when letting up on the pedal.

Okey, of course. smile.gif Didt think of that.

Do someone know the procedure of adjusting that rear drum brakes. I did a search, but didt find what i needed.

Do i have to remove the rear wheels, i heard that its not nessesary to do that. And where is that "star wheel" located?

Thanks

Yes, one has to remove the wheel to adjust the brakes. The backing plate has no slot for the adjusting tool.

Remove the wheel, see either an oval hole or the imprint to punch out the oval hole. Once the oval hole is there, look inside with the slot on the bottom and shine with a flashlight to see the star adjusting wheel inside.

Adjust the star adjust tighten the drum, then back off 5 clicks holding the self-adjuster out of the way to allow reverse screwing of the star adjuster.

Thanks

I was down in the garage just a moment ago and did some adjustments. I could not see any oval hole, just some small holes (2 of them) and a strange hole looked like a "e". I took of the drum and screwed a bit on the starwheel(sour thumbs) and i noticed it was harder to get the drum back on, but it was turning free without any drag. Im going to check again and see if there is a punch out hole there. I also noticed that my "pads" was quite worned out, like 2-3mm thick.

Did some bleeding again with a "one man bleeding hose" i that darn hose did fly of 3 times and the fluid was everywere, except on the paint(thank god). Im going to redo the bleeding in the front again since the nipples/bleederscrews in the front was leaking. Must find some threadtape to put on.

Thanks for all your help folks.
(I can't wait until i bought Baer brakes in all 4 corners)

:rolleyes:

I don't recall which brakes you have on the front, but if you have the stock four piston brakes, they are very prone to leaking air in. Any brake fluid leaking around the front calipers?
David

Hi David.

Yes i've noticed this(fluid running out like starstreaks on the tires), and had the front calipers rebuilt, new seals,boots and pistons. They looked fine in the bore. But i saw that when im bleeding them and open the bleederscrew about a half turn, it starts leeking between the threads(as have been sad in the post earlier).

I did a leek test aswell, i pumped twice and then i pressed as hard i could(power brakes) and hold the foot on the pedal for about 2 minuts(shaky leg) and it did't go lower, and no fluid on the cailper or tires or floor. Så i hope it is tight and sealed.

One interesting thing was that the rears wasn't bleedable until after i did my adjustment on the brake shoes(even if i didt do it right) and then there wahere lots of air coming out. Wonder if those drums ever helped me to stop the car? :eek:

Again thaks for all help.
graemlins/beers.gif

Often the bleeders will get rusty and plug up. It is a good idea to remove them and clean the little holes in them if you are having trouble bleeding fluid out.
If you are using a clear plastic hose on the bleeder, put some teflon tape on the bleeder threads and screw it back in.
This will prevent sucking air in past the threads when bleeding due to siphon effect and then the only air you will see in the hose will be what is coming out of the system.

The stock 68 calipers have cup type seals. The more pressure you apply the more they seat on the bore. However at low pressures they can leak if there is any corrosion or wear of the bore.

This is the same system used on early Corvettes and I've had vette calipers that didn't leak but would suck in air when driven over rough pavement. It seems the vibration shook the pistons enough to allow air entry.

I went with a corvette club to Reno Nevada over the sierra mountains, the road was rough in the slow lane from heavy truck traffic and they use chains at the high altitude portions which were the roughest sections, the road was all chewed up.

We were driving in a long "convoy" of cars so we had to drive in the right hand lane quite a bit to allow traffic to pass us. When we got to Reno, my brakes were almost to the floor, the rears quit working entirely and the brake warning light came on. I went to a local vette shop to have the brakes bled, and there was a line of corvettes five cars long with the same exact problem!

I'm not saying this is your problem since your brakes are low all the time. I would install new rear brake cylinders as they are very cheap.
David

It might be the same reson for the leaks i had. In this town i live in (Gothenburg) they have these Tram(cable buss) tracks all over, and above that the streets is like the streets in Berlin after the bombings in 1945(i think). When i had the car at the "motor vehicle inspection" they find that the bracket which is attatching the calipers to the spindle was loose, and the explained why my car always was draging slightly to the right when braking and still had even brake results at the "motor vehicle inspection".

Im gonna adjust the rear drums a little more if i find those punch-out holes and see if the pedal will engage higher up.

It is still winter here in Sweden so i cant drive out side(i did a little run when i found out that the pedal still was going low) because of the road salt they are spreading out to remove the ice.

Have any one here bought Baer's "Serious Street" 11" brakes kits?

Thanks