Bleeding Brakes - Can't Get Any Pedal Pressure Options

[ThinAir]

Well, I've searched, but there are so many responses about bleeding brakes that it's almost impossible to sort through them... so I'll ask.

I replaced the front calipers on the '70 with a pair of those pretty ones from Eric. When I put the car up on stands for the job I had good brake pedal pressure. Now that the new calipers are installed and the lines reconnected I've bled the brakes. I blocked the reservoir vent. I use a Motive Power Bleeder.

I'm sure that I'm not getting any air out of the bleeders at the wheels, yet I have no resistance when I press the brake pedal - it just goes straight to the bottom.

It seems unlikely that the MC would go so suddenly, so I'm wondering what else it could be.

As always, this is work that is being done last minute to get my son's car ready for this weekend's Route 66 Ramble. Despite lots of trying, things never seem to get done well ahead of time!

[davesprinkle]

Well, I've searched, but there are so many responses about bleeding brakes that it's almost impossible to sort through them... so I'll ask.

I replaced the front calipers on the '70 with a pair of those pretty ones from Eric. When I put the car up on stands for the job I had good brake pedal pressure. Now that the new calipers are installed and the lines reconnected I've bled the brakes. I blocked the reservoir vent. I use a Motive Power Bleeder.

I'm sure that I'm not getting any air out of the bleeders at the wheels, yet I have no resistance when I press the brake pedal - it just goes straight to the bottom.

It seems unlikely that the MC would go so suddenly, so I'm wondering what else it could be.

As always, this is work that is being done last minute to get my son's car ready for this weekend's Route 66 Ramble. Despite lots of trying, things never seem to get done well ahead of time!

You've still got air in the master cylinder. I've used both the Motive Power Bleeder and the McMark Long Tube method. The Long Tube is better. The Motive Power Bleeder just doesn't move the fluid fast enough for good bleeding.

For either method to be effective, though, you've first got to get the air out of the MC. Start with a helper doing the pedal tango until you've got even a little action at the pedal. Then move to the Long Tube method and keep pumping fluid through the lines. It'll take a while.

[ThinAir]

You've still got air in the master cylinder. I've used both the Motive Power Bleeder and the McMark Long Tube method. The Long Tube is better. The Motive Power Bleeder just doesn't move the fluid fast enough for good bleeding.

For either method to be effective, though, you've first got to get the air out of the MC. Start with a helper doing the pedal tango until you've got even a little action at the pedal. Then move to the Long Tube method and keep pumping fluid through the lines. It'll take a while.

That's what I was thinking too. I'm not familiar with either of the methods you mentioned. I'll do a search for them, but if anyone can post a link to a thread describing them it would be appreciated.

I'm assuming that "pedal tango" means having my wife hold down the pedal while I bleed the rear calipers - or is there some fancy footwork way of getting air out of the MC?

[davesprinkle]

You've still got air in the master cylinder. I've used both the Motive Power Bleeder and the McMark Long Tube method. The Long Tube is better. The Motive Power Bleeder just doesn't move the fluid fast enough for good bleeding.

For either method to be effective, though, you've first got to get the air out of the MC. Start with a helper doing the pedal tango until you've got even a little action at the pedal. Then move to the Long Tube method and keep pumping fluid through the lines. It'll take a while.

That's what I was thinking too. I'm not familiar with either of the methods you mentioned. I'll do a search for them, but if anyone can post a link to a thread describing them it would be appreciated.

I'm assuming that "pedal tango" means having my wife hold down the pedal while I bleed the rear calipers - or is there some fancy footwork way of getting air out of the MC?

The Long Tube Method: Get about 15ft of clear 1/8"ID vinyl tubing from the hardware store. Insert one end into the open brake fluid reservoir. (I like to tape the tube onto the fender so it stays in place.) Put the other end of the tube on the bleeder nipple. Open the bleeder about 1/4 turn. Sit in the driver's seat and pump the brakes. Over and over. Until your leg gets tired. Then switch legs. You can watch the bubbles chasing themselves through the line. Do all 8 bleeders. This approach will leak a little fluid past the bleeder threads, but I've never had it pull air back into the caliper.

The pedal tango is just the std method of having a helper stand on the pedal while you work the bleeder: Pedal down, bleeder open, bleeder closed, pedal up, repeat.

You might try the helper method to get some fluid into the MC, but when you feel it working, I suggest switching to the Long Tube method. The advantage of the Long Tube method is: A-- it works really well and B-- it'll save your marriage.