No brake pedal
Thread Starter
8th Gear
Joined: Jan 2025
Posts: 8
Likes: 2
No brake pedal
Replaced brake lines, and installed new rotors, calipers, and pads. After bleeding the brakes multiple times I can pump the pedal and get it to hold but once I take my foot off the brake pedal the next time I press the pedal it goes to the floor. Found and replaced a leaking banjo bolt and washers but the problem persists after bleeding again
Safety Car
Joined: Mar 2017
Posts: 3,771
Likes: 940
From: Orlando Florida
Did you bench bleed the master to begin with? It can be very difficult to get a slug of air at the top of the line system to move all the way through to the end bleed screws.
Also may well be air trapped in the ABS module. Are you doing a pressure bleed, or traditional pump the pedal and hold? Pressure bleeding has the best chance of getting air all the way through. That said, in my experience it is imperative that the outlet tube, attached to the bleeder, end below the surface of brake fluid in a container. Just ensures that no air has a chance to travel back if a siphon develops. And also from my experience, Mighty-Vacs are good for many things, but brake bleeding is not one of them.
I've got a Motive unit, it works a treat as long as you can get a seal.
https://www.motiveproducts.com/produ...c-bleeder-kits
Also may well be air trapped in the ABS module. Are you doing a pressure bleed, or traditional pump the pedal and hold? Pressure bleeding has the best chance of getting air all the way through. That said, in my experience it is imperative that the outlet tube, attached to the bleeder, end below the surface of brake fluid in a container. Just ensures that no air has a chance to travel back if a siphon develops. And also from my experience, Mighty-Vacs are good for many things, but brake bleeding is not one of them.
I've got a Motive unit, it works a treat as long as you can get a seal.
https://www.motiveproducts.com/produ...c-bleeder-kits
Tech Contributor
Joined: Jan 2007
Posts: 19,461
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From: Dyer, IN
What order are you bleeding the calipers?
What method are you using to bleed the calipers?
Also, did you replace lines all the way up to the master?
Thread Starter
8th Gear
Joined: Jan 2025
Posts: 8
Likes: 2
I installed new powder-coated calipers and stainless steel brake lines from the hard line to the caliper but didn't replace the master cylinder. I'm bleeding the calipers RR/LR/RF/LF as recommended by the tech manual.
Last edited by 01redragtop; Jan 14, 2025 at 01:05 AM.
Thread Starter
8th Gear
Joined: Jan 2025
Posts: 8
Likes: 2
I didn't replace the master cylinder. I'm using Russell speed bleeders. As I mentioned, I've bled them four times with the same result. I suspect I may have hosed the master cylinder.After all, it is 24 years old. In addition to ordering a new master cylinder, I'm using a Motive pressure bleeder
Last edited by 01redragtop; Jan 14, 2025 at 01:08 AM.
Team Owner
Joined: May 2001
Posts: 87,367
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From: Western NY
I didn't replace the master cylinder. I'm using Russell speed bleeders. As I mentioned, I've bled them four times with the same result. I suspect I may have hosed the master cylinder.After all, it is 24 years old. In addition to ordering a new master cylinder, I'm using a Motive pressure bleeder
However, I would give consideration to the fact that the speed bleeders are designed to operate with the pressure applied by the brake pedal, which I'm pretty sure is significantly more that the line pressure that is achieved by a Motive bleeder. My suggestion, at this point, would be to put the OE bleeder screws back in place, and try bleeding the lines, one more time.....
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Tech Contributor
Joined: Jan 2007
Posts: 19,461
Likes: 1,166
From: Dyer, IN
I didn't replace the master cylinder. I'm using Russell speed bleeders. As I mentioned, I've bled them four times with the same result. I suspect I may have hosed the master cylinder.After all, it is 24 years old. In addition to ordering a new master cylinder, I'm using a Motive pressure bleeder
Race Director
Joined: Oct 2004
Posts: 12,864
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Agree with leadfoot. I also have Russell speed bleeders. But if yours have been used a couple times, you may need to reseal the threads with either Teflon tape or Teflon pipe sealing compound. I prefer the compound, but that's just me, and mine have only been used once when brand new, so I've never had to reseal them....Yet.....
Safety Car
Joined: Mar 2017
Posts: 3,771
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From: Orlando Florida
If you are using a pressure bleeder, Motive or otherwise, the speed bleeders are irrelevant, they are just one way check valves to prevent air flowing back into the calipers, which the pressure bleeder already prevents. You pressurize the master cylinder, then bleed as though there was a non-stop foot on the pedal -- unless you run out of fluid in the reservoir.
Team Owner
Joined: May 2001
Posts: 87,367
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From: Western NY
If you are using a pressure bleeder, Motive or otherwise, the speed bleeders are irrelevant, they are just one way check valves to prevent air flowing back into the calipers, which the pressure bleeder already prevents. You pressurize the master cylinder, then bleed as though there was a non-stop foot on the pedal -- unless you run out of fluid in the reservoir.
Melting Slicks
Joined: Sep 2021
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You could take that a step further, and say that if you're using a pressure bleeder, then the "speed bleeders" are unnecessary. And while typing my other post, I began to wonder how much line pressure is required, to the "speed bleeders" in order to overcome the bleeders' internal spring, and allow brake fluid to freely flow. Is a Motive bleeder able to produce that pressure? When using my Motive bleeder, I generally pump it up to about 8-10 PSI....
Thread Starter
8th Gear
Joined: Jan 2025
Posts: 8
Likes: 2
You guys are great. Thanks for all the helpful suggestions. I decided to replace the master cylinder with an AC Delco part since it is 24 years old. I've already had to replace the clutch master cylinder. I'll bench-bleed the master and then retry the bleeding process using my Autel MaxiCOM 808.
Tech Contributor
Joined: Jan 2007
Posts: 19,461
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From: Dyer, IN
I'm at my wit's end. After replacing my brake lines, calipers, and a bench-bled master cylinder I can't get any brake pedal after multiple bleeds. I'm using an Autel 880 and can't get the system to complete the ABS bleed. The system calls for opening the left front bleeder screw as the Autel begins the ABS bleed process. The second step is to bleed the right front caliper. Unfortunately Autel never cycles to this second step. I continued to apply a gentle pumping motion to the brake pedal but it only resulted in draining the master cylinder. Is there anyone out there with experience with the Autel system that can shed some light on what I'm doing wrong?
Did you get rid of the speed bleeders and install regular bleeders to get that variable out of the equation as suggested?
I find it strange that the Autel is telling you to bleed the brakes opposite of what is required. I have never bled brakes closest to the master and worked my way farther away.
The automated bleed is only required when air is suspected in the secondary circuits....or.....the BPMV has been replaced. In any case, manual or pressure bleeding is required as a first step before pressure bleeding.
Thread Starter
8th Gear
Joined: Jan 2025
Posts: 8
Likes: 2
I did get rid of the speed bleeders. The process for bleeding the ABS is different than bleeding the rest of the system. It does call for bleeding the front wheels first. I can't get the Auitel to move past the first step (right front wheel). Once the ABS is bled the next step would be to bleed the calipers starting at the right rear then left rear, right front then left front. As I mentioned I've pressure bled the calipers numerous times to no avail. What am I missing?
Drifting
Joined: Sep 2022
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Dumb suggestion, have you maybe got the calipers on the wrong sides, make the bleeder port below the fluid level in the calipers?
I have yet to do a Corvette, whether it is even possible, but I had a Mustang that a guy had swapped calipers on and couldn't get it to bleed and he had installed the calipers on the wrong sides.
I have yet to do a Corvette, whether it is even possible, but I had a Mustang that a guy had swapped calipers on and couldn't get it to bleed and he had installed the calipers on the wrong sides.
Drifting
Joined: Sep 2022
Posts: 1,452
Likes: 1,115
So, I would say you have them on the wrong sides, need to swap them over.
******** Yeah, just looked at a pic of the calipers******
The bleeder screws should be at the TOP, so you have them on the wrong sides for sure if they are at the bottom on the car.
Last edited by Ltngdrvr; Jan 20, 2025 at 01:10 AM.