I have just replaced all the brake components, such as master cylinder, front and rear calipers. I have bled the lines many, many times but I am still not getting the pressure. Following all this I still need to pump the brakes 3 times to obtain the pressure needed to come to a stop. I used the pump and hold process, which is what I am accustom to. Can someone please provide some insight as to what I am missing or is there something not working correctly? Could it be the Brake Booster? Thank you

 

It sounds like you installed the master cylinder without bleeding it. If so you can still gravity bleed the master cylinder and calipers but it'll take a lot longer because the master cylinder will have to fill first. It could take a whole hour for the air to get purged out of the master cylinder so be patient.

 

With my 80 it was tough getting the air out with just pumping. If the person pumping up and holding until you crack the fitting is a newbie, it can get frustrating. I had to power bleed the system to finally get all the air out. You did bench bleed the master??

 

When I had similar problems this is what I did. My car is a 78.
I removed the master cylinder cap and opened 1 caliper bleeder from the front and one from the rear (opened enough to allow the start of gravity bleeding). Then I slowly would press the pedal to the floor. Note if the pedal moves smoothly or if you feel a change in pressure. Once to the floor I would slowly releash the pedal. I did this for about 5 minutes. Always check to make sure the master cylinder doesn't go dry. Once I completed this step, I would then open only one bleeder at a time. I used a DIY Master cylinder plate connected to my air compressor set for 20 PSI to provide pressure to the system. Then I would open the bleeder. I would also bang with a rubber hammer, and open the close the bleeder rapidly to help the air move on.

I would then drive the car and heat up the brakes as safely as possible and then do one more power bleed.

I am assuming you have new brake pads installed. If not it is sometimes difficult to get the air behind the pistons all out with 1/2 worn pads. The back calipers are harder to bleed because the position of the calipers. They need to be more upright to bleed better.

 

i put braided steel lines in the other day, i have bleed many brakes in my lifetime.... i am no expert at all...



my c3 is a joke, I tried 3 times and still can't get a hard pedal


it seem.... many are just as frustrated with the whole BS process....

 

GRAVITY BLEED THEM ... You will think it is a Magic trick ...

Top off master ,, open rear bleeders and let it run until it is a steady drizzle ,, close them ..do sane with front close bleeders and your done ..Just make sure your master never goes empty ...

 

Thank you guys, I did not bench bleed the master cylinder

 

http://blog.daviescorvette.com/2010/...1982-corvette/

i did this sequence and it worked

 

I ran into the same problem on my 1981. I tried all the methods mentioned herein.
I finally broke down and bought a mechanical/vacuum brake bleeder called a MyTyVac. Got it on sale at a local auto supply for $40.00 or so.

Go get one or a similar model, it will save you a lot of headaches. Start at right rear, go to left rear, right front then left front. Keep the master cylinder topped off during the process.

Good luck.

 

I just replaced all 4 calipers, pads and Master cylinder last weekend. All parts were O'reilly's stock stuff. I just bled them just like every other car I have done this on for the past 40 years starting with right rear outboard bleeder then right rear inboard bleeder, move on to left rear, right front, left front. My little wife pumping and releasing brake pedal upon my command. I did bleed the master cylinder before installing. Pedal and brakes work perfectly. I just don't like the noisy pads, they sound like they are scrapping.

 

I just got over the nightmare of this brake system. I tried to bleed the brakes on my 79. The brake light was on, the pedal went to the floor, and no fluid was coming from either the front or rear brakes. My left rear caliper was leaking, I replaced it. I replaced the master cylinder (after bench bleeding it), I got a firm pedal but the replaced caliper was leaking!!!!! I took it back to Advance Auto and got another one. I then attempted to bleed the brakes again and no fluid came from the right rear caliper. I bought a right rear caliper along with hoses and replaced them both and went to drive the car and heard a scraping sound from the right rear wheel. I removed the caliper and took it back to Advance Auto. This store gave me an unpainted caliper (it was gold)! I went to another AA store and got another RR caliper. After replacing it, I got my Motive Pressure bleeder set up and when I went to open the left rear inner bleeder screw, I ended rounding off the corners on it!!!! I had to remove the damn caliper to get the bleeder screw out with vice grips. To make matters worse I had extra bleeder screws to replace that one but I could not find them!!!!!!! I took the power bleeder from the master cylinder and the rear reservoir was completely empty!!!!!!!! So guess what??? Had to remove the damn master cylinder and bench bleed it again!!!!! After bench bleeding the master cylinder and setting up the pressure bleeder I was finally able to bleed the system. After bleeding, I finally had a firm pedal and I reset the combo valve by driving and heavily applying the brakes getting to brake light to go out. With all of that said I do think this brake system can be very frustrating to bleed. My 96 jaguar xjs convertible has fixed 4 piston calipers like the c3 brakes but are in no way as difficult to change pads or bleed the system. In your case bench bleed the master cylinder, then bleed the system... gravity bleeding works, but imo it takes too long, two man method also works, but also takes too long, vacuum bleeding, reverse bleeding also work. I like using the motive pressure bleeder, one man job, short time to bleed.

 

20 some years ago while bleeding my L82 for the first time, I couldn't get all the air out.... of course I didn't read no steenkin manuals for simple brake jobs. I did not know there were two bleeders on those massive brakes. Note for nubes.... like me... get the manual. And if you don't.. look for multiple bleeders on each caliper.

 

I am going to try your method but I have one question..

May I assume that there is no need to have a helper do any brake pedal pumping at all????

mk's78

Mike

 

Zero helper ,, Open top bleeder on both rear calipers and KEEP master full .. let it go till the stream is steady and close them ..do sake at front KEEP master full lol