Bleed the brakes

[resq302]

I bet your whole problem was with the air in the master cyl.  Now that you have eliminated that, try doing a gravity bleed.  If that still doesn't work. Try working your way back from the rear to the front and crack each of the fitting connections open and see if you leak out any fluid.  If you do, you know you have a problem in that section.

[Belgium R/T -68]

I bet your whole problem was with the air in the master cyl.  Now that you have eliminated that, try doing a gravity bleed.  If that still doesn't work. Try working your way back from the rear to the front and crack each of the fitting connections open and see if you leak out any fluid.  If you do, you know you have a problem in that section.

With pedal pressed down then? Or with disconnected lines at m-c and forcing oil in that way?

Per

[FLG]

Fill MC and crack open bleeders....sit back with a cold one and watch some TV, just keep an eye that the master dosnt empty.

[Belgium R/T -68]

Fill MC and crack open bleeders....sit back with a cold one and watch some TV, just keep an eye that the master dosnt empty.

With the pedal pressed down? Otherwise I don't see how the oil could leave the mc?

Per

[b5blue]

No it should just drip out slow if you have the top off the master.  (you do not touch the peddle)

[Belgium R/T -68]

No it should just drip out slow if you have the top off the master.  (you do not touch the peddle)

Doesn't work MC very good bleeded but no oil comes out from it unless I push the pedal.

Per

[dpixel]

No it should just drip out slow if you have the top off the master.  (you do not touch the peddle)

Doesn't work MC very good bleeded but no oil comes out from it unless I push the pedal.

Per

Make sure the bleeders are opened up enough.  The cover should be off the master.  Give it some time too.  It's not going to gush out of there.

[Belgium R/T -68]

Tried everything, even used "the machine" again to fill from rr and open bleeder at lr and oil is coming out. Aftet that I tried bleeding with
my vaccumpump but all I get is airbubbles, oil doesn't start to run. Pedal still goes down to the floor. I guess my last alternative is to try
to find a device who press the oil in from the mc. Maybe swapping mc, have another one laying. Don't know anymoore.

Per

[resq302]

Ok, if you are not getting any dripping from the bleeder screws, try my idea of cracking open the line where it connects to the master cylinder.  If it drips out, tighten it up and go to the next further connection back on the line.  At least this way you can see where you have a problem.  I had a problem once with my hold off / proportioning valve for my rear brakes that it would not let the fluid back up to the master cylinder.  Basically, when I pressed on the brakes, my rear wheels would be locked up even after I took my foot off the brake.  By going to each connection and cracking the line open, I was able to find out exactly where the problem was.

[b5blue]

Well if you even touch the peddle with a bleeder open all you do is suck air back in there. There is the possibility of a crappy new M/C coming to you but I would think it would still bleed (?) I just changed out my M/C today, I bench bled it and swapped it out with the old one and lost so little of the fluid that the car was drivable without finishing bleeding the system. Do this, use that thing you got to shoot fluid from line to the rear by undoing the connection at the M/C and going from there back. With that line full and the master bled it must gravity bleed. If the peddle still drops...the M/C is defective unless the peddle linkage is improper or adjusted wrong. Do you have power brakes?

[Belgium R/T -68]

Yes, I have powerbrakes. I have opened the brake hold off valve and checked that oil is coming from both sides and thru it. Distributionblock
is working because I get good oilflooding from calipers and the line going to the hold off valve. If there should be a airleak at either the rear
brakehose-line or rearaxle tee I should have had oil coming out there when I pressed oil in from the rear bleeders or?
What about testing for leaks with airpressure? Risc for damages?

Per

[b5blue]

You have some fluid out the rears now yes? Good fluid flow to front yes? Is the rod from the booster to M/C adjusted for proper length is my next concern to short and peddle moves without moving plunger in M/C. Rod too long and plunger can not return all the way back to rear of M/C to get a full seat for next stroke. Next are rear shoes adjusted out to snug against drums so slave cylinders can't flex outward and are pistons for disks up front snug to pads and pads to rotors. Do you get what I mean? Anything in system that can "give" will let peddle go to floor and screw up trying to get good peddle "feel". With everything as stated it has to bleed. I had hoped you had it set today!

[Belgium R/T -68]

You have some fluid out the rears now yes? Good fluid flow to front yes? Is the rod from the booster to M/C adjusted for proper length is my next concern to short and peddle moves without moving plunger in M/C. Rod too long and plunger can not return all the way back to rear of M/C to get a full seat for next stroke. Next are rear shoes adjusted out to snug against drums so slave cylinders can't flex outward and are pistons for disks up front snug to pads and pads to rotors. Do you get what I mean? Anything in system that can "give" will let peddle go to floor and screw up trying to get good peddle "feel". With everything as stated it has to bleed. I had hoped you had it set today!

Very good points on the brakehardware Will check it up after I'm back from a 2 days businesstrip to Germany, load up my batteries.
I know I have adjusted the rod but never knew what it was for. Brakeshoes are rather tight to drum I think so maybe there are some
possibilities anyway.

Per

[b5blue]

Have a safe trip! 

[Belgium R/T -68]

OK, back in town. I adjusted the rod both ways but no difference in pedalresponce, just keeps hitting the floor. If there was a leak it
should pour out somewhere? If it's air you should still be able to build up some pressure on the pedal since it's oil in the system or?

Per

[six-tee-nine]

Per,

If you disconnect the lines from the master cil and it is bled correctly oil should pour out of the holes, and when you step on the pedal it should spray out of it.
If so connect them again and go further down, loosen or disconnect the next connection (before proportioning valve) pump the pedal. If the part above is ok then oil must come out after pressing the pedal. then connect again. Loosen next connection......etc.

However, if the master is bled correctly, i'm damn sure you can fill the lines easily by pressing the pedal with the bleeders open (still one at a time)

Here some education about the master cilinder so the gravity bleeding and pedal up/down thin gets cleared out...:



There's more here :

http://auto.howstuffworks.com/auto-parts/brakes/brake-types/master-brake.htm

[Belgium R/T -68]

Thanks Koen This would suggest that my mastercylinder is a problem, it doesn't let any oil thru unless the pedal is activated/pushed.
Will also check tomorrow if the brakeshoes are to tight adjusted but I don't see how that can make the pedal go to the floor.

Per

[Belgium R/T -68]

Benchbleeded another mastercylinder (same type) and mounted it on the car, same result. Took the first mc to bench and bleeded
that one, now that one squirts oil/air thru the holes in the reservoar while pushing in the cylinder. Is that normal? The oil passing the bleedhoses
don't contain air and now suddenly it pores oil out of the nozzles without cylinder pressed in.
Checked brakeshoes and they are adjusted just fine.

Per

[b5blue]

Bleeding the master you keep pumping till all air bubbles stop, it is important that it is level when you do it and you don't pump fast. Steady even pressure all the way to the bottom and I like to slow the return so it takes 3-4 seconds for the springs to push the piston back. You checked the booster's plunger rod length so it is just long enough to fit inside the master but not move the plunger any right.

[lisiecki1]

Benchbleeded another mastercylinder (same type) and mounted it on the car, same result. Took the first mc to bench and bleeded
that one, now that one squirts oil/air thru the holes in the reservoar while pushing in the cylinder. Is that normal? The oil passing the bleedhoses
don't contain air and now suddenly it pores oil out of the nozzles without cylinder pressed in.
Checked brakeshoes and they are adjusted just fine.

Per

yes that is normal, put it back on the car and try again....

[Belgium R/T -68]

Connected front and rear port of mastercylinder and you can't push the piston in anymoore Atleast that should mean
my mc is OK. The rod I have tried all different positions, even took away the retainer between the booster and mc to make the stroke longer.
Will try the shortest stroke.

Per

[b5blue]

  now we are getting somewhere......

[Belgium R/T -68]

Learned today that the rod adjusted to minimum lenght still press the mc piston in a 1/4". I loosend the mc a little bit to let the piston
go all way back but there was no difference from before in pedal. Question is, is it possible that I have got air back in the mc while the rod was
wrongly adjusted?

Per

[b5blue]

Yes I think so, do you have a spacer between the booster and M/C? (my 70 has one about 1/4-3/8 thick)

[Belgium R/T -68]

Yes, I do have a spacer of the same thickness as you mentioned. I guess cutting the rod in the boosterend or removing the nut
are the options I have because it has to seal not to loose vacuum.

Per