Help.. Cant find source of air in brakes

Hi everyone,

Please help with some ideas. I am totally at my wits end now.

I have a 70 type I bug. I have always had a difficult time with the brakes on this guy. About 2 years ago I got frustrated and sent it to my local repair mechanic and had them fix it for me. That cost about $600, to replace everything, but they stopped working well about 6 months later.

My son was complaining that he had very little brakes, so checked them out. The front brakes were not working at all. I bleed all 4 wheels, and had lots of pressure until suddenly it gave way. I assumed that a seal was blown in the M/C.

I replaced the M/C with a new one from Napa. It is marked made in the USA and cost about $60.00. When removing the old M/C I stripped the nuts on both metal lines to the front wheels, so I replaced them too. Once installed, the brake lights would not work, so I replaced the pressure switches. Then I adjusted the peddle plunger for a small amount of free play before the peddle actuated the plunger. I bleed the rear lines, and then the front lines. I was still getting lots of air in the wheel cylinder (right front), so I assumed it was leaking. I replaced it too with a Napa cylinder.

I still get lots of bubbles coming from both front cylinders. The rear cylinders seem to be bubble free. I have been using clear tubing about 10 feet long to be assured that I have replaced all the fluid in the system. Some how air is getting into the front system, but there is no signs of leakage of oil when the system is under pressure. Everything has been changed except for the two rubber hoses and the left front cylinder. These were replaced 2 years ago. The pedal is rather soft still.

What is the bolt on the top of the M/C, above the discharge port to the rear wheels? I thought it was a bleed point for the M/C, and loosened it when I first bleed the system. I have retightened it. When I disassembled the old M/C it seemed to be a divider between the front plunger and the rear plunger. Could I have messed up something when I loosened this as the peddle was being pumped?

One other thing, when I sent this to my mechanic 2 years ago he moved the location of the front wheel cylinders from 12:00 to 9:00 left and 3:00 right. I was afraid they were each retaining air in the cylinder because the bleed point was no longer at the highest point. I removed the cylinders and placed a C clamp on them to keep the pistons from coming out and bleed them unattached so I could move them around to be certain all the air was out of them. I have moved a lot of fluid through those cylinders yet they still produce bubbles. Should I remount the cylinder back to the top position?

Any advice you could offer I would very much appreciate. This group has been very helpful to me these last few years, Thank you for your help.

Robert

Reply to
Robert Rutler
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sounded more like a brake line going out, unless the master was leaking fluid out of it's rear (pedal area)

Did you install Metric lines? If you didn't that could be a problem although the SAE shouldn't fit, they may give you the impression that they do. :-(

Rare for both front wheel cylinders to be full of bubbles, unless maybe the brake light switches are bad/not tight, or air is getting in by way of the reservoir hoses. Were there caps on the top of the inlets pipes of the master cylinder? Not too much to go wrong hydraulically here, inlet hoses, master cylinder, brake light switches, brake lines, hoses and wheel cylinders.

**************************************************************************** Yes that is a possibility that maybe the air is getting in through there now. maybe you need to check to make sure it is tight and not leaking. You may need another master cylinder if there is internal damage. :-( ****************************************************************************

I don't think the mechanic moved the position of the wheel cylinders, unless you know this for a fact. The rears are at top of the backing plate and the Beetle fronts are towards the rear of the backing plate.

JMHO and good luck with your search! later, dave Reminder........ Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you are a mile away from them, and you have their shoes. Frieda Norris

Reply to
dave

dont but a MS from napa.

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Reply to
Jim Buys

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