wibs

Oops, I didn't see this part and I was pumping the pedal to release the piston and now I get a squeaking noise from the pedal/somewhere in the engine bay near the firewall (or at least that's what it sounds like from the inside of my car).

Did I damage a seal here? My brake fluid level is low so I figured that was just what happens when there isn't a lot of fluid in the system (bled the front wheels so far, working on my first of two rears) but the lines should still be full of brake fluid in the front as I didn't flush the system, just bled what I needed to to compress the piston.

Help?

Just Me

add fluid, bleed, and you tell us.

I strongly advice buying a pressure bleeder like a motive.

They are great.

i hope all's ok with your MC

G

wibs

Hrm...

All four wheels back on and the car is ready to drive... I turned the ignition and pumped the brake twice, pedal had zero resistance, it would have hit the floor had I pushed down further. *sigh*

Time to go find the motive power bleeder locally as my carh as to be driveable today.

Oddly enough, I didn't find any bleed screws on my rear brakes so I didn't drain any fluid there to make the piston's retract (just had to use a lot of force on the piston tool.

I'm guessing I just bleed the front brakes since those lines probably have the air in them or do I have to bleed them all (if so, where are my bleed screws on the rears, there was nothing on the caliper)? I don't have a conceptual picture of what's happening in my brake system right now so this is a bit of trial and error. If anyone has a diagram of what's happening,feel free to post a link so I can better understand. (I come from a technical background so I like over the top analysis/schematics

Just Me

what year and model? I have never seen a car without bleeders on every caliper. In fact, it must exist.

G

wibs

2008 A4 2.0T Quattro

I took about 100 pictures during the job and I just finished reviewing them. I think I found it. It was covered with dust and it looked like a bolt when I had the caliper off, if it is indeed the bleed screw then my mystery is solved.

I'm going to take the tire off right now to check.

I found out the nearest motive dealer to me in Chicago is in Sawyer, MI, 96 miles away. I guess I'm making a road trip today.

*Making a road trip in the wife's civic, the Audi can't stop right now

wibs

yes, that was it. I wish I knew where to get the proper "clear" hose. I don't have the power bleeder yet and I know that'll have the clear hose I need. It's 96 miles to the nearest motive dealer so I'll try to manually bleed the system first and if no go, will go on a road trip.

Question, when I bleed the system, the DIY says to keep the "box wrench" on the bleed screw at all times but doesn't show a pic of that being the case. Does it matter really? I just want to make sure the fluid goes from one closed system to another and the other end needs to be in old fluid to ensure any air bubbles are forced down the tube into the container and then the air can escape out the open end of the container... Why does the bleed screw need to have the wrench on it at all times? I'm missing something. I'm also assuming I need someone to pump the brakes so the pedal will help push the fluid out the bleed screw I'm working on so I don't have to compress the piston to push the fluid out...

It all seems logical to me so far but I'm no expert.

Just Me

the point is that you should be able to close it in a jiffy - for example if you realize that you are getting low of fluid or????

Also, don't use a box wrench. Get a proper line wrench so you dont round it.

To get a box wrench off, incidentally, you would have to remove the hose from the bleeder.

G

wibs

Well, now I have some issues... I just did a 45 minute long bleed of the entire brake system (drained out 1 pint of fluid between all four wheels). I put something under the pedal so it couldn't hit the floor this time and then did the bleeding in the correct order (got my clear hose from home depot, the 1/2" vinyl clear hose was perfect) and a little air came out but when I got to the front passenger side, a ton of air came out on that one. I had the wife keep pumping the brakes (half pumps) until all the air (a reasonable guess) was out of the front passenger side. I got some out of the front driver side but not a lot. Once I was done with the fronts, double checked that all bleed screws had been shut and no leaks, I tested it. the pedal still had a lot of give so then I tried turning the car on and the pedal went all the way down to the box blocking it from hitting the floor.

Now I'm concerned. I need to try a power bleeder next but I'm not sure that's the answer at this point considering what I've seen/been through. I'm really really hopeful that I just didnt' get the rest of the air out as my fear is I killed my master cylinder.

One thing of note, I compressed my back passenger piston probably a bit too far, the gasket around the piston head started to deform due tohow far it was compressed. It didn't stop like the front one did, is it possible I destroyed that piston and that's letting air back into my system somehow or is that more of a cosmetic issue? I'm not sure how the rear piston's work exactly (I need a how-stuff-works diagram, will go search it after thsi).

I wish I knew someone locally who had a power bleeder so I could test it before driving 200 miles RT just to test a theory.

A new master cylinder (genuine audi part from a website I found) is $220 before shipping/taxes.
Any suggestions? I was very meticulous about the bleed so I know no air got back into the system. The brakes are more firm now than they were before with the car off in park but with it on, I have zero resistance and the brake fluid level is full.

Help?

wibs

My Motive bleeder comes tomorrow but I don't have a VAG-COM tool to open the ABS pump which will probably have air in it considering how much air I let into the system. Anyone in the Chicago area have one I can borrow this weekend?

I'm planning for the worst right now and hoping for the best. If I need a new M/c,would any of the following work for me? (tirwling/TRW I think is my model to replace) or would you guys recommend spending the 230+ for a genuine audi part. My car is a CPO and has 48.5k miles on it.

http://www.discountbrakes.com/shop/?...ster+cylinders

Just Me

when i do my brakes, the first couple of pedal pumps go to the floor as the pistons adjust. Then all is well.Have you doen that?