$25 to whoever diagnoses my brake problem

[shumpertdavid]

he means if the calipers are upside down (bleeder facing down not up)

[aggie97]

I chased several brake problems on my wifes 99 SS for nearly a year. Very similar to what you have had so I will give my experiences.

1. She had ABS deleted as well.
2. The ABS delete plumbing was drawing air and NOT leaking fluid when the pedal was released.
3. Master cylinder was BRAND NEW and was leaking at the plunger. We replaced it too.
4. somehow, we could not get the air out of the m/c on the bench unless the fluid was all the way to the top of the reservoir. Somehow it was drawing air back in when it was released.

The solution that worked for us. I put a new M/C in, problem got better. I put an ABS unit back in place, it fixed the problem. The issue I think I found was the incompatibility of the STOCK double flares and all the off the shelf stuff. It was drawing air BADLY. I ended up having to tighten the lines so much, they deformed and started leaking. The previous shops working on the car used brass PIPE fittings to make some stuff work. I ended up getting a lot of lines from the junkyard and put it back to stock as close as I could with a couple specific modifications for our racing use.

NOW The brakes work AWESOME. I haven't hooked up the ABS yet, but it bled and works fantastic on track.

Post pics of your ABS delete setup and I might be able to give you some advice....but if it uses those short stainless flex lines that used to go into the ABS unit, my bet is that it's drawing air at those fittings due to incompatible taper on the flares.

Good luck!

[ZYouL8R]

Update.

Replaced the MC with one off another LS1, same issue. So as I suspected, it's not the MC.

So there's either a leak at one of the fittings that I can't see, or one of the calipers is bad. Could a caliper cause an issue like this?

[flybye70ss]

i had an issue like you describe and after going over everything, it was the steel braided brake lines that were the problem.

is air in all 4 corners when you bleed? is someone helping you when you are bleeding?

[ZYouL8R]

i had an issue like you describe and after going over everything, it was the steel braided brake lines that were the problem.

is air in all 4 corners when you bleed? is someone helping you when you are bleeding?

I'm not finding much air anymore. I haven't for the last few bleedings (is that a word?).

My problem now is the very spongy pedal.

[Clifton]

he means if the calipers are upside down (bleeder facing down not up)

What he said. Post a pic of your calipers.

[Captain Crawfish]

if youver added aftermarket stuff to it i would look towards what aggie is saying. maybe the existing flared lines arent sealing with the aftermarket items. just because you dont see fluid doesnt mean they arent drawing in air

[91cavgt]

I have seen where people pump the brakes too fast and that causes bubbles to be in the system. When you pump, pump them slow. But since you have used a power bleeder and there's still bubbles, something has a lot of air in the system. A cracked fitting or line or a bad connection won't draw in air with the entire system under pressure when you're power bleeding. Something tells me it's how you're doing it that's the problem.

[ZYouL8R]

What he said. Post a pic of your calipers.

For the 69th time, the calipers are NOT upside down.

The bubbles have been gone for a while now, but the new MC didn't fix the extremely spongy pedal. I think my next step is to isolate the calipers one at a time and see if the pedal improves.

[shumpertdavid]

I have run into a few customer cars that had caliper alignment problems. Make sure all your caliper mounts, shims, brake pads, and caliper hardware are squared up and seated well. I ran into a couple cars where the calipers would mount with a small amount of angle because they were not seated well or a caliper pin was binding. The pedal would be soft because instead of applying pressure to the pads it would try to move the caliper or take up the gap.

[ZYouL8R]

I have run into a few customer cars that had caliper alignment problems. Make sure all your caliper mounts, shims, brake pads, and caliper hardware are squared up and seated well. I ran into a couple cars where the calipers would mount with a small amount of angle because they were not seated well or a caliper pin was binding. The pedal would be soft because instead of applying pressure to the pads it would try to move the caliper or take up the gap.

Everything seems ok, but I'm going to investigate the calipers more in depth today. I'm going to have my wife pump the brakes while I watch the calipers to see if there's any abnormal movement. Thanks for the suggestion.

[shumpertdavid]

Everything seems ok, but I'm going to investigate the calipers more in depth today. I'm going to have my wife pump the brakes while I watch the calipers to see if there's any abnormal movement. Thanks for the suggestion.

This is how I found the problems when I had them. The caliper will have some movement as it "floats", but will be minimal.

[Emwun Garand]

Solution.

Sell car

[ZYouL8R]

Another new finding...

Now I'm getting bubbles when I bleed the rear calipers, but none when I bleed the fronts. So there's either air getting into one of the lines going to the rear, or is it possible that one of the internal seals in the MC is bad towards the front (the line going to the rear)? Most of the bubbles are small, soda type bubbles, but every once in a while I'll get a big one. None on the fronts.

BTW, I didn't notice any abnormal caliper movement. All the guide pins seem to be functioning normally as well.

[shumpertdavid]

Another new finding...

Now I'm getting bubbles when I bleed the rear calipers, but none when I bleed the fronts. So there's either air getting into one of the lines goig to the rear, or is it possible that one of the internal seals in the MC is bad towards the front (the line going to the rear)? Most of the bubbles are small, soda type bubbles, but every once in a while I'll get a big one. None on the fronts.

BTW, I didn't notice any abnormal caliper movement. All the guide pins seem to be functioning normally as well.

You could possibly still be getting some air in the rear from when you were swapping master cylinders around. At this point you almost need a fresh set of eyes to look at it with.you. it seems that you are overlooking something or possibly have a connwxtion problem somewhere.