correct way to bleed the brakes
 

ok I just changed my pads and rotors and blead the brakes. The way I did it was by starting with the passenger side rear and having my fiancee sqeeze the brakes down to the floor and hold while I loosened and tightened the bleeder nipple and did that reapetedly all the while checking and making sure I didn't run out of brake fluid in my master cylinder. After that one was done I went to the drivers side rear. Well about 10 minutes ago I got in the car and was about to go for a test drive when all of the sudden I was backing out and I couldn't stop because the brakes went all the way to the floor. I would pump them and it would start braking however as soon as I pushed on the gas and then on the brake it again would go all the way to the floor. What is wrong? Thanks.

Did your fiancee pump the brakes like a lot of people think you are supposed to? Hopefully she didnt pump then hold but just slowly pressed down. Also, you are supposed to put a 2X4 under the brake pedal so that it doesnt touch the floor all the way. Or your fiancee might have let her foot off of the pedal when you still had the bleeder screw open and sucked a ton of air into the system. Other than that, Im not sure. Good luck

ohhhh wait a minute your not supposed to push it all the way to the floor?

By your account, seems like it should have worked. Some tips, from the Haynes manual: 1. you might have two bleeder valves per caliper, and you should use the bottom one since you changed the rotors 2. did you put the open end of the bleeder hose into a jar of clean brake fluid, instead of open air, to watch for bubbles 3. if you have ABS, bleed the ABS hydraulic unit

I don't think the s4's had abs did they? I used the top ones so tomorrow I'm going to use the bottom ones. Oh yeah by the way are you supposed to depress the peddle all the way to the floor? Thanks.

I always put the pedal to the metal when bleeding. But then again maybe that's not proper and I don't know what I'm doing. Been successful though.

My S4 doesn't have ABS. I was just going by what the manual says, which doesn't specify which year. I doubt that S4's have ABS, but you'll be able to tell by not being able to find the ABS hydraulic system in your engine bay. :)

The manual says to depress all the way down. Maybe somebody with more experience knows the right answer.

You're supposed to open the bleeder when the pedals up, then have them push to the floor/wherever, tighten, repeat until all the air is out.

If you push the pedal all the way to the floor, 90% of the time nothing will happen. I always used to do it that way and never had a problem. So nothing may happen. I was told this from a master technician who has been teaching a brakes class for 20 years however. He said to put a 2X4 under the pedal.

ok so wait a minute you let the person pressing the brake pettle push down then up then you open and close the valve? That is totaly differant than what I was doing. I was making her hold it to the floor, open and close the valve then have her release. THis is not right? THanks.

you open the valve. then have the person push the brake, then your close it, and tell them to let off, they your open it, and have them push it down again all the way to the ground all the time. then close it and then tell them to let off the brake. so its, open,brake,close,let off brake. do this untill there arent any bubbles

sounds good thanks and someone else said I should use the bottom one instead of the top one. Is this true? Thanks.

i dont think it really matters. but you might as well just do the bottom to be safe

You always bleed starting with the wheel furthest from the master cylinder and work your way to the closest one. Then bleed the ABS pump. When bleeding brakes I use about 6" airline tube. One end on the bleeder nipple and the other end in a container of brake fluid. That way only air comes out and if the person stepping on the brake lifts their foot before you close the screw no air gets back in. Also ABS was an option on S4. My S4 has ABS. Now I have the same problem as you. Peddle goes to the floor but if I pump it pressure builds up but as soon as I let go I'm back to square one peddle goes to the floor. In my case my ABS pump decided it was time to go. Mine sucks in air everytime you hit the brake pedal causing the same problem you are having. If you are doing the bleed procedure correctly (sounds like you are) and still getting air in the system then you want to check the brake lines and make sure they aren't wet. Then check the ABS pump (if equipped), proportion valve and master cylinder for leaks. Just out of curiosity, why did you start bleeding the brakes if you just changed pads and rotors?

well basically my car has all red hoses and front tower bar in the engine bay along with a red msd6a and the outside is all black with two silver racing stripes but the last paint job the painter painted the turbo in front and back red so to go with the hole red thing I descided to paint my calipers red witch requires you to remove the calipers for sanding and washing.

NEVER push a used master cylinder to the floor. Here's why:

A "wear ridge" will develop over time in the cylinder bore where the piston stops. When you push the piston PAST that wear ridge, you run the risk of damaging the seal as it slides past that 90degree lip.

If the front piston seal is damaged, the brake fluid will seep past it into the rear piston bore. This is called "bypassing". There won't be any external leaks. If the rear seal is damaged, fluid will leak out of the rear of the m/c, potentially into the brake booster; ruining it.

Sounds like this is what happened to your car.

Here are a few more common brake mistakes:

When "pumping" the prake pedal before bleeding (which isn't really necessary btw), you should GENTLY & SLOWLY pump the pedal. If one is too violent, the air trapped in the system will be broken in tiny bubbles. These bubbles will stick to the surfaces inside the hydraulics. Later they will coagulate into a larger bubble & you'll have shitty, if any brakes.

While installing a new master cylinder, the common wisdom used to be to "bench bleed" it. There is however a better way to initially bleed it. Bolt the empty master cylinder to the car, don't connect the lines. Obtain some "plugs" that will screw into & seal the holes in the m/c. I've found that by using scrap, metal brake line ends, You can obtain a perfect seal. If you don't have any old lines laying around, buy some new short lines from an auto parts store. Cut the lines about 1" from the ends. Crimp off, fold over, & crimp off the ends again: perfect seal. Screw these ends into the m/c loosely, add fluid to the resevoir, when fluid begins to drip past the ends, tighten the fittings.

Fill the m/c to the "full" level, install the cap (very important). Get inside the car & press the brake pedal, slowly & firmly, several times until the pedal becomes rock-hard & won't budge. The m/c is now bled. Remove the plugs one at a time, re-install the lines & bleed your brakes.

Bleeding is easily acomplished by yourself using the mason jar & vacuum hose method someone described above.

Good luck.

j.p.

wait a minute I'm reading in the haynes manual and it says there is a bleeder valve on the right and left front however mine doesn't have that. Are the right and left front only for abs cars? Thanks.

*****A "wear ridge" will develop over time in the cylinder bore where the piston stops. When you push the piston PAST that wear ridge, you run the risk of damaging the seal as it slides past that 90degree lip.****

That makes good sense to me. Thank you.

***wait a minute I'm reading in the haynes manual and it says there is a bleeder valve on the right and left front however mine doesn't have that. Are the right and left front only for abs cars? Thanks******

I've yet to see a car that did'nt have a bleeder on each brake assy. On my 86-87 they all have a bleeder. Once you find it, you might buy one of those EZ Bleed devices at the PePBoys. It's just a rubller hose that fits over the bleeder and on the far end a one way valve that you emerse in a Coke bottle/mason jar/whatever jar, with enough brake fluid in the bottom to cover the one way valve/check valve. Then you loosen the bleeder a turn or so and then slowly depress the brake pedal......let it slowly return...slowly depress the brake pedal, let it slowly return...and on and on until you stop getting bubbles in the bottom of the Coke bottle. Making SURE that the brake reservoir remains FULL all the time while doing the above. Something like that.

where is the bleeder on the s4 tII front calipers? does anyone know? Thakns.

On my series four, turboii, the bleed nipple is on the aft side of the brake caliper, towards the top. Maybe your missing seeing it because it has a rubber dust cap on it???? Mine have that rubber dust cap over it. All brake calipers have a bleed nipple.

yup I found it today and got them blead, then I took my car out and no turbo spool, if its not one thing its another.

i just bled my front calipers and i just used a hose on the bleeder screw and a cup of clean brake fluid. Did it by myself and it worked out pretty good if i do say so myself

would it be better to bleed the brakes from the bottom nipple? i just bought some speed bleeders and im curious to which nipple would be best to install it on

Still confused on why you had to bleed your brakes for a pad/rotor change?

James

You should use the bottom bleeders after changing calipers, but you can't go wrong if you do bottom and then top to be certain.