412 brake bleeding sucks

[DeathBus]

My 2 door.

So far I have

removed and cleaned brake fluid resevoir, and all rubber lines
rebuilt master cylinder.
rebuilt front calipers
removed took apart and cleaned rear pressure regulator
removed and cleaned rear wheel cylinders

put 5psi air on resevoir, still cant get much fluid out of system.

WHAT am I missing besides maybe all the lines being clogged (with as much pressure as I have on it I would not think this would be a problem).

[ubercrap]

Well, I'm certainly no expert on brake bleeding, but I have an Eezibleed setup, and it uses a spare tire connected to it at 20psi. It goes into a bottle that holds fresh brake fluid first and pushes it through a hose that connects to the brake fluid reservoir. Even then, I got in and pumped the pedal a bit to help things along when I was flushing the fluid in my GTI recently (says to try that in the directions IIRC). I haven't tried bleeding any Type 4 brakes quite yet... I don't know if this helps any?

[DeathBus]

Well, I'm certainly no expert on brake bleeding, but I have an Eezibleed setup, and it uses a spare tire connected to it at 20psi. It goes into a bottle that holds fresh brake fluid first and pushes it through a hose that connects to the brake fluid reservoir. Even then, I got in and pumped the pedal a bit to help things along when I was flushing the fluid in my GTI recently (says to try that in the directions IIRC). I haven't tried bleeding any Type 4 brakes quite yet... I don't know if this helps any?

It does help, I think I will up the pressure tomorrow, just dont want to bust the resevoir.

I am basically using a rubber hose connected to a cap that fits the resevoir and putting pressure on that from the tank, I have gotton alot of air out of the system, but just trickles of fluid. Should I get a full stream on this type of system, I have bled 100's of buses and beetles and have always been able to get a great flow of fluid.

[Longbeach412]

Yes, 5psi is definitly not high. I think 30psi would be more like it. Think of all the multiplication your break cylinders do to your initial foot pushing force ( say ~ 20lbs) and the area of the master cylinder piston.......bla, bla.

[raygreenwood]

Forget the power bleed on the 412. It does not work that well. You have to remember, that power bleeding does not really add any pressure to the system until you are on the return stroke. You need to stroke back slowly in order to make sure the compensation return ports stay open long enough for pressurized fluid to get anywhere.

One thing that can help is to start at the right rear, Then left rear. Then right front, then left front. The object is at first.... is not to worry about making sure you have all the air out. Its just to get fludid moving in all directions equally and start chasing the air.
Make about 8 pumps....slow pumps....slow down....slow up. Do this on each wheel. This is to make sure that the tank is replenishing. Slow pumping is at first better, because the air actually moves freer in the pipe than the fluid. All you do is suck fluid back and forth. When you go to the front...the first time, do the top and bottom bleeder valves. After that , just the top valves. This will take about 4 rotations of the car.
Next....high pressure rapid pumping. This is to make sure that small air bubble are not bypassing at the top of the bends in the body. I think the one man bleeder valve is best actually. When you set it up...you need to zip tie it onto the valve. Also, use some thick grease around the threads of the bleeder valve. They suck air back in.

Make note. When high pressure bleeding...with high foot pressure and rapid FULL stroes...you must have the bleeder just baaaaarely cracked open...so each pump builds considerable pressure. This is compress all of thair bubbles as much as possible to get proper movemment out of them. This does the most work. It should take about 3 seconds for the pedal to get full stroke to the floor if the valve is cracked open properly.
Make about four rounds of the car this way. Drive and repeat.
NOTE
Make very sure that the brake pedal stroke is properly adjusted before you start. Make sure the rear brakes shoes are very closely adjusted...make sure the e-brake iss off. Ray

[albert]

hi, ray , for me , for to bleed the hose brake on my 412 , i remoove the thank cover and i remoove the bleed screw , put can for recupération and i waiting dripping oil by gravity for 15-20 minutes in the same time i keep the thank full all the time and , afther i thight the bleed screw ,i do that for the 4 weells one by one and i d,t, know if that is good , but the car have good brake,,, albert

[raygreenwood]

Thanks Albert! That also helps if you are not in a hurry. It chases most of the air to the high points in the line. Ray

[albert]

hi,ray, for air intake boots , i go during the weekend in my favorite scrap yard and i see , 2or 3 good boots for the 412 on différent model of car , subarouille (ops sorry subaru car ) and toyota, and g.m. car same size but more long only ,cut 2-3 inchs and that fit perfect ,,,albert

[vwbill]

I use a hand held vacuum/pressure/pump/tester with the reservoir in the line between the nipple and the vacuum pump and pump it to 20-25lbs and then open the valve slowly and move from right rear around to the front left then I do like Ray described and just do a standard pump slowly and hold it with a 2x4 against the driver seat and the pedal and open the valves again till I get pedal pressure. I remember on my old one having to move around from wheel to wheel so much my back and shoulder would get bruised,lol! Need to make a hose system with tees to hook up all the bleeders to one reservoir and open all the valves all at once and pump it clean some how,lol! Bill

[raygreenwood]

Bill, by the way...your seat looked quite excellent. I could live with that if they have the patterns. I would also like to see how they treated the panel on the back if you get time. We could always get a group buy for the materials at sew fine and have them dewn at your guy. Thanks Ray

[DeathBus]

Bill, by the way...your seat looked quite excellent. I could live with that if they have the patterns. I would also like to see how they treated the panel on the back if you get time. We could always get a group buy for the materials at sew fine and have them dewn at your guy. Thanks Ray

Dont hijack my brake bleeding WITH your seat covering!!!

[raygreenwood]

Hey...at least you arn't bleeding all over your seats because of your brakes.... Ray

[DeathBus]

Hey...at least you arn't bleeding all over your seats because of your brakes.... Ray

That will happen tomorrow when I try tu adjust the pedal!

I found the resevoir was clogged. Took it out and the clutch side was completely clogged while the 2 brake ports had doo doo in them. I clean both out. power bled the brakes again, got real good flow and realized my pedal was not engaging the master cylinder as it should, said "I'll screw with it tomorrow"

the clutch pedal pumped right up, of coarse with all the air still in the system it faded pretty quick.

[MGVWfan]

He said doo doo!

Thanks for the tips guys...I have to replace the right rear wheel cylinder again, that crummy Brazilian thing my local B/A place sold me is leaking. I'll get a chance to use your advice.

BTW, I use an Eezi Bleeder (pressure on the reservoir) plus an evacuated chamber hooked to the wheel I'm bleeding (two coffee cans soldered together with a hose fitting at the bottom, hooked to my vacuum pump through a flare fitting at the top). I've never needed any pedal manipulations with my MG or US cars, but I noticed I had to do what you guys are describing with the 412, slow movement of the pedal to get the fluid flowing.

[raygreenwood]

Yep. It has to do with a few things. The stroke length and volume between the compensation flap valves, the size and location of the replenishment ports etc. Fluid just does not readily flow in this system. Ray