[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

Re: [T3] Brake Notes


On 15 Jul 2004 at 11:19, Jens Vagelpohl wrote:

> 
> On Jul 15, 2004, at 12:14 AM, Jim Adney wrote:

> > That's right. Pumping the pedal just speeds it up. All the component 
> > drillings
> > are arranged so that the chambers will fill and the bubbles will leave 
> > from the
> > top where the exit ports are.
> 
> Last question ;) How long does it usually take you to bleed a system 
> that way?

Probably about 20 minutes. I bleed one wheel at a time, just to avoid wasting 
fluid. And I go around the whole car twice. It's nice because by the time I get 
to this point on a car I'm ready to take a breather and this is a nice one. All 
I have to do is move the bleed bottle from wheel to wheel and open the bleed 
valves. While I'm waiting on a wheel I can be keeping the reservoir topped up.
 
> P.S.: Having worked in shops (both commercial on new cars and on my old 
> VWs) I always hated bleeding the brakes. On the old VWs that could not 
> be "pressure-bled" like the new cars I'd have someone sitting in the 
> car while I and the bottle were under the car. I'd open one nipple, 
> yell at the other guy to push down and hold, then close the nipple and 
> yell again to let go of the brake pedal. Very annoying process.

I started out doing it that way, too. Like you, I hated it. 

Eventually, I settled on the looped hose method, where I make sure the hose 
loops up as it first comes away from the wheel and then drops down to the bleed 
bottle. I've spend a LOT of time under a car watching the fluid flow back and 
forth as the pedal goes up and down, and I  will testify that it rarely backs 
up significantly, even with vigorus pumping. You're fine as long as you have a 
hose, and the looped hose is even better.

Maybe the important thing to realize is that even if a bit of air gets sucked 
back in on the upstroke, that air will be the first thing expelled on the next 
downstroke. So only the very last upstroke matters, and if you use a looped 
bleed hose then the only thing that can be sucked back on that last upstroke 
will be brake fluid.

BTW, you CAN pressure bleed our VWs, you just have to be a little careful with 
the pressure you apply. 30 psi seems to work fine (doesn't explode the 
reservoir.) I haven't tried much above that, and I think I only did that one 
time when I was having some trouble that I thought this might cure. (It 
didn't.)  

Snap-On makes a pressure bleeder adaptor for our reservoirs. I don't own a real 
pressure bleeder, and I couldn't afford to fill one with the silicone brake 
fluid that it would need. If I made my living at this, however, that's the 
direction I would go.   

-- 
Jim Adney
jadney@vwtype3.org
Madison, WI 53711-3054
USA

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]