simpsoap

It's been a long winter and I completed a lot of projects while the car was tucked in the garage (new post and pics coming soon). I replaced all the pads and rotors, replaced the lines with Stainless Steel lines as well as powdercoated the calipers. Today was the first day I was able to drive the car and I noticed on the way to work that the brake pedal felt spongy. If I pumped it a couple of times, it firmed up, but depressing the brake pedal without pumping resulted in a spongy feel. Could I still have air in the brake lines? I didn't notice any leaks in the garage, so I'm assuming it could just be air in the lines. I flushed the system and bled the brakes with my Motive power bleeder. I did this until the fluid came out with no more air bubbles. Possibility there could be more trapped? How long does it take to do a complete flush and bleed the brakes?

Also, I noticed that the "Anti Lock" light is on, and all sensors were replaced.

Andy

Stealth 993

You might have some air in the lines, & that can cause the ABS light.

Bleed them again, & if you have a durametric scanner (scan for ABS light code), activate the ABS to pump the old fluid out of it. You should start at the passenger rear, drivers rear, passenger front, then drivers front. Don't forget that each caliper has 2 valves. Use less pressure on the bleeder, & still pump the brakes, slow & steady, but do not go all the way to the floor.

simpsoap

Interesting, so even with the bleeder set at 10psi, I still need to pump the brakes? I assumed with the bleeder there was no pumping necessary. As for the valve, I replaced everything, so I did bleed in the correct order starting with the outer most valve.

Andy

e9stibi

10 PSI? One of the forum gurus (Steve Weiner) wrote to a question that I had quite a while ago that 1- 1.5 should be sufficient and more is not good for the system.

PorscheDoc

I have a feeling he meant 1-1.5 bar pressure. I use to set it at 15psi when I use to use the pressure bleeder. Since then I have gone to vacuum, much better, less messy system.

Stealth 993

Yes, even with the bleeder, you can get some air bubbles in the system. I used to use one all the time, then I found out that you can get better results the old way, & use less fluid. With my bleeder, I set the pressure low, & just use it to keep fluid in the res.

I bet when you did the SS lines, you had a empty system, there is a good chance there is a few small air pockets in there. When a system is run dry it can take a few bleeds to get it back 100%.

AOW162435

Soap,
Sounds like air in the lines.

I've done a complete brake/clutch fluid flush every winter for the last 5 years using the Motive Black Label bleeder and ATE Super Blue. I only use the Motive to pressurize the system (20 psi), and stop occasionally to top off the reservoir. As such, the inside of the Motive is as clean as when I initially purchased it - no brake fluid to clean up, etc.

I work my way around the car (farthest caliper from the reservoir first) and tend to do the entire job within 30 minutes (including the clutch circuit).

Hope that helps.


Andreas

simpsoap

Thanks for all the help guys. Looks like I got all the air out of the lines, or the majority of it. The brakes feel as they should, and the pedal feels nice and tight. I worked my way around the car and did each of the calipers. I didn't get the "Anti Lock" light to go off, figured I would read more on that tonight and see if there are some suggestions. Unless any of the guru's here have some ideas???

Thanks again!

Andy

Mike J

Is the pedal firm after you pump it, or does it slowly drop? If it drops slowly with significant foot pressure, the seals in the master cylinder could be gone (you did not use full swings of the brake pedal anytime during the flush...that can cause issues).

I use about 8-10psi on a number of cars, no problems. I agree with most of the posts, you likely just have some residual air in the system. The air bubbles will tend to gather into larger ones, so bleed it again and see what comes out.

Cheers,

Mike

Pete Lech

When you completely drain the system, the ABS pump can get air in it. (I know from experience).

Bleed the car again, but turn on the ignition to cycle the pump before doing each caliper several times. I did it 3 times per caliper.

simpsoap

Mike:

The pedal is now nice and firm, and doesn't drop at all. I made sure that when I was bleeding the brakes that I didn't depress the pedal all the way to the floor, I went about halfway.

I never thought about air getting into the ABS pump, so maybe I need to try turning the ignition on while bleeding the calipers. Might have to get this a try this weekend.

Andy

g_murray

Hi,
What the others have said...

Also, remember, the ABS light will come on if one or more of the wheels have been OFF THE GROUND AND ROTATED - independently of the others. The ABS sensor will 'know' this - and will 'respond' by turning on the ABS light. When you drive the car for - about 50 miles or so - the ABS system then 'comes to terms' with the 'new' status quo - and will turn the light off.

Gerry

simpsoap

I've driven the car more than 50 miles, but the light is still on. I'm assuming there is some air in the abs pump, so I'm going to bleed them again this weekend. Hopefully that solves the issue.

Andy

Marc Shaw

I usually thump the calipers with my fist a few times while bleeding which helps to dislodge air bubbles - I also will (gently) whack the hard and flexible brake lines with a small (10 mm) wrench while bleeding - again, to dislodge air bubbles......seems to help.

Marc

AOW162435

Gerry,
I've never had my light come on and have rotated the wheels many, many times for one reason or another while the car is on stands. It's even been on stands, idling in first gear after a tranny fluid change. No issues whatsoever.

You better save that for Sunday...


Andreas