My turn to seek help with brakes

[nlvtinman]

I have a problem to open up for the help and advice of the rest.
I have '67 I'm building and I keep having trouble bleeding out the air as I bring the brakes back to life.
I have an entirely new system, nothing is reused but the reserve bottle. AC industry front disc, type 3 rear, all new steel lines, braided flex hoses, a NOS ATE/VW master.
Using vac system to draw the brake fluid into the system, I cannot stop air from entering. And this even happens when depressing the brake pedal and bleeding that way.  I do get a low/spongy petal so I know it's trying. 
I have checked and rechecked every connection, bipassed each component in the hope to discover where that air is enteting, all without success.
I've redone brake systems before so I am not a first timer. I've just never had this occur.

What might I be overlooking? I am at wits end with this.
THANKS
Steve

[Rick Meredith]

Did ya put some grease around the threads of the bleeders?

I've seen them pull air there under vacuum.

[nlvtinman]

Rick, THANKS.
Such a simple and as of yet untried idea. Off to the garage so I can find out if you have hit on my solution.
Steve

[56BLITZ]

Rick, that's a good tip that should be considered S.O.P. when installing new brake cylinders/calipers. I like to use anti-seize on those threads.

a vacuum bleeder certainly could draw air around the bleeder threads, but that air won't be going back into the brake system, and I will be surprised if this solves this problem . . . you told us that " this even happens when depressing the brake pedal and bleeding that way". If you have a helper pump the pedal properly, and you close the bleeder BEFORE the pedal is released, the bleeder will be under pressure all the while it is open.

Do you get plenty of fluid flowing out of the bleeder as you bleed each wheel and are you seeing the air bubbles?

You said "I do get a low/spongy petal so I know it's trying". Is your pedal low because only one circuit still has air in it. That is, are the rear brakes working and the fronts have air? Determine that first so you can eliminate half of the places where the problem might be. If you have an Ohm meter and a helper, we can figure out which end is working.

[56BLITZ]

You are using the A.C. industries kit with the part #401510, right?

[nlvtinman]

First I gave Ricks thought a try and I'll be , the slight flow of air bubbles into the cup of thre MightyVac stopped. Simple.
But as I open the bleeder I still have a flow of air in the fluid stream.
I've the problem that I have no one that can assist me in conventional pedal depressing and opening the bleeder. All my neighbors on my street are old, or widows. My friends work when I'm off, and I work nights when they are home. Thus the Mighty Vac as a necessity.

With it being a holiday here (in the USA) plans take me from getting much more done today.
56BLITZ, I'm going to go to give your help a looking into as well. Someone has to be seeing what I'm overlooking.
As for the AC Industries part #401510 that is the one.

[Taylor]

I can come help you on Thursday Steve.

[56BLITZ]

I can come help you on Thursday Steve.

Attaboy, Taylor!

If you are doing this by yerself, you will need to buy, or build, another type of tester.
OR, does the car have a battery and wired up with the brake lights? You can disconnect the wires from one of the brake light switches, turn on the key, and see how far you can push the brake pedal when the brake lights come on, and then do the other switch the same. One switch is for the front and one is for the rear.
Or have you determined already which end is working?

I have a thought about VW wheel cylinders and the use of a vacuum pump on them . . . .sooooooooo . . . . it would be nice to know if the problem is in the front or the rear!

[kingsburgphil]

Eons ago when I worked at VW dealers, we used a one man pressure bleeder. It pushed pressurized fluid thru a reservoir cap. Messy, but fast and effective.
Obviously it helped show leaks in the system and it didn't care if the system was stock or modified.

[Rick Meredith]

a vacuum bleeder certainly could draw air around the bleeder threads, but that air won't be going back into the brake system, and I will be surprised if this solves this problem . . . you told us that " this even happens when depressing the brake pedal and bleeding that way". If you have a helper pump the pedal properly, and you close the bleeder BEFORE the pedal is released, the bleeder will be under pressure all the while it is open.

Agreed. It won't let air back in as long as the bleeder is shut before the vacuum is released.

[nlvtinman]

Phil, I'm old enough that eons ago it was possible to run to a salvage yard and pick up a spare reservoir cap and build up a pressure bleeder. Ahahaha, sure not going to find a early enough VW in a yard in Las Vegas.

56BLITZ..this car is a long way from being with battery power, so to check which side of the system putting brake lights to task isn't possible. But it sure a good suggestion.

With the many find helpful ideas of each of you I'll go to work tomorrow and see what side of the system is not active.
THANKS, Steve

[richie]

Is it possible that one of the seals is bad in that NOS master cylinder? how old do you think it is?

cheers Richie

[plasticblack]

Is it possible that one of the seals is bad in that NOS master cylinder? how old do you think it is?

cheers Richie

Hi Steve

I'm off the same mind as Ritcie. That NOS matser Cylinder might be your problem.

 Often these items are badly stored over time and are not servicable even before they get to you?

   Some quick inspection might reveal more.

    Keep us posted. 

     Paul

[Rick Meredith]

Phil, I'm old enough that eons ago it was possible to run to a salvage yard and pick up a spare reservoir cap and build up a pressure bleeder. Ahahaha, sure not going to find a early enough VW in a yard in Las Vegas.

56BLITZ..this car is a long way from being with battery power, so to check which side of the system putting brake lights to task isn't possible. But it sure a good suggestion.

With the many find helpful ideas of each of you I'll go to work tomorrow and see what side of the system is not active.
THANKS, Steve

You could rig up something with a small light bulb, some wire, a couple of alligator clips and a AA battery. If I remember (and I'm sure someone will catch it if I'm wrong), the switches are insulated from ground so you can just clip across the terminals and the bulb will light at the point that the pressure switch makes contact.

[Lee.C]

I had exactly the same problem on my ex's 1302......

It turned out to be a tiny hole in one of the hoses.... I would just Double and triple check EVERYTHING 

[nlvtinman]

Although the master is a "collectable" in it's age, I disassembled it, cleaned it and checked every thing before installing. All like new as I've always kept it stored in the house.
I know that the new master that came with the AC Industries kit was absolutely not working. Bench bleeding it, it Barely pushed through any brake fluid. unsafe POS.
Reading another forum last night, the guy who replied said on a dual circuit system to bleed the fronts first.  My VW service manual doesn't mention that, but what's to loose?
As for building a self powered electric tester, a portable system sounds like a good plan.

I again appreciate all the help. I am sure the fix is to be found to be a simple one, but after trying to discover what that is on my own, I knew where to turn to for good help.

[whirligig]

I know its something you will have done BUT is there free play on pedal push rod ,if its holding the cylinder open at all then it wont clear properly.

[61SNRF]

The bleeding procedure outlined in the '66-'69 Bentley manual section 7 page 25 will work with only one person. That method uses a rubber hose that fits the bleeder nipple tightly with it's other end immersed in a clear bottle containing a little fluid.

The same manual in section 7 page 32 says to bleed the fronts first on dual circuit systems.

If that doesn't work head to Home Depot and pick up an English speaking Day Laborer

[dragvw2180]

 This is something so simple people overlook it, make sure your bleeder screw is at the highest point posible so that air does not get caught in a pocket inside the calipers . I have had to remove my calipers sometimes to change their position to get air out of them when bleeding .  Mike McCarthy

[j-f]

This is something so simple people overlook it, make sure your bleeder screw is at the highest point posible so that air does not get caught in a pocket inside the calipers . I have had to remove my calipers sometimes to change their position to get air out of them when bleeding .  Mike McCarthy

I did this mistake. I didn't pay attention when mounting the calipers and mounted them with the bleeding screws on the low side. It was just impossible to bleed them.

[hotrodsurplus]

I know its something you will have done BUT is there free play on pedal push rod ,if its holding the cylinder open at all then it wont clear properly.

X2. I beat my head against the wall one night in 1992 trying to bleed the brakes on a '65 Type III. If the pushrod holds the piston down just a slight bit then the system won't bleed properly.

Same goes with the bleeder-screw orientation. I beat my head against the wall another night in 1997 trying to bleed disc brakes in a '67. It was only when my friend asked how the air trapped above the bleeder screw would come out when I realized I had the calipers flipped side-to-side. I installed them properly and all was well with the world again.

All that beating my head against the wall when I was a kid was what made me as smart as I am today.