First let me clarify I was having no brake issues. I was simply doing a 200K miles maintenance and was changing brake fluid. So before I started all worked fine.
I pumped out the reservoir leaving about 1/2 inch of fluid in bottom. (Same as on my wife’s car). I refilled with new fluid to top. Replaced cap.
I then bled the lines in order recommended (rear drums first) and they seemed to go well, but when bleeding the front brakes my wife indicated the pedal was very spongy. I finished up as normal but brakes are very soft. After watching videos I decided to bleed the master cylinder. I bought a bleed kit and bled it still installed. Lots a bubbles came out and the pedal hardened up and bubbles stopped. I thought hey it’s fixed. I closed up the MC and cranked the truck and started to drive but problem returned…
I am curious if I can just bleed the lines now? Or should I start over and bleed the MC again before the lines?
I have ABS module in middle of truck under the drivers seat. But remember all was working well before I started so I find it hard to believe that I now have bad parts?
I am going to guess you own a mid 2000s year truck (you don’t say)… so you should be able to change the brake fluid without exercising the ABS valves. I’ve done my 04 several time that way.
That said, if you introduced a bubble in tbe master, you should crack the master’s lines after bleeding the master. Break the lines loose enough for a small amount of fluid to escape. Use gravity only. If the pedal is still soft, bleed around the vehicle again. Gravity bleeding works as does the pedal or pressure method.
If you have the scan tool to cycle the ABS, use it. If you can’t get the system bled that way, it may take a trip to the mechanic. But I have never needed the scan tool.
Bleed MC lines using gravity. To be specific do I loosen both lines enough to leak and have partner press the brake pedal to force air out? Do they hold the pedal in as I tighten the lines or do they release the pedal before I tight lines? I saw a Scotty Kilmer video where he held petal down entire time as lines were bled and retightened.
After the MC bleed DO NOT crank truck or drive it. Immediately bleed all 4 lines.
Gravity, no pedal needed. Crack one line at a time and close them as soon as fluid comes out. Removes the bubble from the high spot.
Yes, don’t start it, don’t crank it. Bleed all 4 lines.
Then hope you can get the system bled without it. If not, @testers procedure is the method you’ll need to use, and that will take a trip to the mechanic for you.
Before you do this, look carefully for brake fluid leaks near the ABS modulator. These vehicles are rather notorious for rusting out the metal brake lines down by the ABS modulator.
I’ve personally blown both front and rear circuits at the same time so it completely drained the master cylinder. My after-repair successful fill and bleed was as I described to you without cycling the ABS valves.
Ok guys thanks for help… it’s fixed. No leaks at ABS or anywhere.
Bled the MC with gravity. Pedal tightened up. Then bled each line. I tried using a bleeder pump on first line but air just kept coming in around the valve. I got some help and did the 2 man job where he pressed the pedal, I opened the valve and closed it before he released the pedal. Did that a couple times per tire with no air and just solid stream of fluid. It was more messy but I wiped it up.
Results = my brakes are firmer than ever before, or like new from factory. Very happy!!
You would need to seal the bleeder screw threads will silicone paste or air will be drawn in when the pedal is released. Not much air but some customers can notice the difference in quality of the brake bleeding process.