ok...Brakes...

[sharkskinman]

got a MC rebuild kit and installed it
how should i bleed them
should i crack each apart and let them gravity bleed
do i need to take the front calipers off and see if they will even move?

i have been pumping for 15 min at least
and it has only went down about 1.8" in the reservoir

im believing the system was almost barren when i got it.

should i crack them off the cylinders and see if i have fluid at them ?

its hot and im flustered...
rear cylinders look brand new
but the fronts look rusty...

just fed up at the moment

[bradey bunch]

heres how i do it. if you just onstalled the master, bleed there first, by pumping the master, and as you hold the pedal, crack both lines, then tighten them up and pump it up again. make sure not to lift up the pedal when the lines are cracked or you will pull in lots of air. repeat a few times to fill master with fluid. then make sure all your bleeders will crack open so you know if you have to replace calipers or wheel cylinders or not. spraying them dopwn with penetrating lube like gibbs or fluid film can help. tighten them up after you know they will open. then get a friend to hold the brake pedal down as you crack the rear passenger bleeder, and tighten it up while he keeps holding the pedal. then he pumps, then holds it while you do it again. bleed there till clean fluid and no air comes out. then go to the rear drivers and do the same. then the front passenger, then the front driver side. all done. you could also power bleed it if you have acces to a kit or use a 1 man bleeder kit.

whatever system you use, be sure to bleed at the master first, otherwise it can take ages to get it bled properly. good luck,


Braden

[sharkskinman]

thanxx
i didnt think of the master cylinder
but the T3s dont have it next to the steering wheel...ha

so do the farthest from first

should i take the proportion valve off and dump it out and fill it up?
will that help

i have checked the rear cylinders and they look brand new

i need to take the front calipers off tomorrow and bang the pistons a bit and make sure they are free

i got the intake manifold boots and intake gaskets so i cant wait till i get the brakes squared away

[bradey bunch]

I wouldnt bang the calipers, just try to push them back a bit (on our kindm the 2 piston design, i usually use a set of external snapring pliers and 2 worn out pads to push them back in.) I dont have a proportioning valve, but I know on certain vehicles it is neccessary to bleed there, but if you are going to take it off just replace it with a more modern adjustable one. until u get a new one i wouldnt touch it unless you couldnt get it to bleed even with my earlier suggestions.

[sharkskinman]

sorry

Bang in the idea of getting the pistons to be free

im going to try it to morrow
altho theres no one around to help

might have to go get a pump

[wildthings]

If you leave the caliper in place you can probably just use a large screwdriver or a pry bar to force the pads back. Or with the pads removed you can use a pinch bar to push the pistons back.

[raygreenwood]

What Bradey Bunch said...and what Wildthings said. If with the bleeder valve open (or not)...a a large screwdriver cannot push the pistons back in their bores.....do not pass go or collect $200...proceed immediatley to rebuilding calipers....very easy. Itsn ot uncommon for calipers on a barren system (especially oen sitting as long as yours have)..to be frozen.

That being said....what Bradey Bunch suggested about bleeding the MC...is a good start. The other issue with 411 and 412 is that their brake tube system is very circuitous. When you are first starting to bleed.....if there is a lot of air in the system...you can commonly find that moving the brake pedal makes very leittle pressure and that it does not draw in fluid from the resorvoir. This is because air bubbles just slide back and forth in the system and you cannot generate enough suction by return piston stroke....to draw fluid in. Its an equilibrium.

What needs to be done generally...is to (a) seal the threads on the bleeder screws with a single strip of teflon tape. The front caliper screws generally suck air. Thick grease can work also in a pinch. (b) make sure the ports where the pointy tip of the bleeder screw seal are clean and rust free. I always buy new bleeder screws. (c) When you open the bleeder....onlu open it ...just barely...maybe 1/4 turn or less. The ibject is tio build up presure by stroking the pedal....and then just open the bleeder enough that you have to force the pedal to teh floor. In this way you keep the fluid under pressure so that it cannot bypass air bubbles in high spots of the brake lines.

Remember that equilibrium thing?
When first bleeding...you must let the pedal up from the floor slowly...like about a 5 second count. If not....again it draws air back and forth in the system instead of drawing in fresh fluid. Ray

[Bill K.]

Ray's old tip of elevating the rear end as high as possible over the front helped me bleed the rears fully. I put my car on an incline nose down and jacked it up to bleed the rears. Multiple passes round and round with drives in between is inevitable to get all the air out.

[raygreenwood]

Thanks for that reminder Bill! There are so many weird little tricks to these cars....I had forgotten those details. Elevating the rear end as a help for bleeding....happened by accident years ago....during a very frustrating new master cylinder install.

But what Bill mentioned that you should be prepared for....is multiple drives...being careful of course....to drive air caught in the system to the ends of the system (the wheel cylinders and calipers). I don't really know if its the vibration, heat or angle changes...or everything combined....that does the most work, but I have never been able to fully and properly bleed a 411/412 brake system 100% without multiples drives and bleeds over the period of a few days. Ray

[bradey bunch]

has anyone ever tried a power bleeder on one of these cars? I used it on my clutch, but not on the brakes. Might be easier than manual bleeding.

[Bill K.]

I use power bleeder (pressurized at reservoir), but still needed multiple rounds with drives in between and rear elevation.

[raygreenwood]

I would agree to that too. Someone pointed out to me many years ago that what is probably happening that prevents a pressure bleeder from doing a complete job on these cars....is that in very high points in the system...probably right where a bend is...bubbles get compressed into bends or dents and allow fluid to bypass. So you get brake bleeding but since bubbles remain in certain places....they compress while fluid doesn't. This is why a few hard to remove bubbles here and there cause a soft pedal. Ray

[ubercrap]

Jesus, can't anything be easy on these things?