[T3] Brake Bleeding

Jim Adney jadney at VWType3.org
Wed May 11 06:09:51 PDT 2016


John,

We're all agreed that if you don't get good pedal on the first 
stroke, there's something wrong.

When you get fluid out, what color is it? If it's dark brown, that's 
rust, and you want to bleed out all that rusty fluid, until you get 
clean amber fluid out (or purple, if you're using silicone brake 
fluid.)

If the pedal sinks down under continuous pressure, or you can never 
get good pedal, or fluid is leaking out around the boot, then you 
have an MC problem.

Do this test: Apply the parking brake. Do you then get good pedal on 
the first stroke? If so, your rear shoes are not adjusted. If not, 
the problem is elsewhere.

Make sure the bleed valves are all clear. They are step drilled, so 
you need 2 or 3 different sizes of drill bits, just spun in your 
fingers, to get to the bottom of each one. Once the bleed valves are 
clear, remove them and use a small drill bit, again in your fingers, 
to make sure that the hole at the bottom of the bleed valve hole is 
clear all the way into the caliper or wheel cylinder.

Make sure BOTH sides of the reservoir are actually full. This is 
often hard to tell, as there's usually a line there that looks like a 
fluid level, but it's actually only a line of residue left from a 
previous filling.

When bleeding, the person at the pedal must first pump up the pedal, 
then maintain his force on the pedal as the bleed valve is opened. 
When the valve is opened, he should feel the pedal sink under his 
foot force. If his foot doesn't go halfway to the floor when the 
valve is opened, you must work your way step by step from that wheel 
toward the master cylinder, loosening one connection after another, 
until you find a point where fluid comes out and the pedal sinks.

Once you've found where fluid comes out, you know there is a blockage 
of some kind between that point and the previous place you loosened 
that didn't leak.

I believe you mentioned that you have the late calipers with 2 bleed 
valves. For those, you can use the top bleeders to get out air, but 
bleed from the bottom also, to get out as much rusty fluid as 
possible.



-- 
*******************************
Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
*******************************



More information about the type3-vwtype3.org mailing list