Problem with bleeding brakes..spongy pedal

[ViperBite]

I'm in a quandry. I replaced all the brakes..pads, calipers, rotors I bought a pressure bleeder as well. Ok, I have run about 3 liters of fluid through the system with the pressure bleeder and have also manually bleed the brakes. What was interesting is that there were particles running though the rears. I think the new pressure bleeder may have contaminated the lines at the very begining. The lines are now clear, no bubbles.

With the manual bleed, the pedal will go to the floor as the manual indicates while I have the bleed screw open on the fronts. On the rears, the pedal does not move as on the front. I do get fluid flow but the pedal is not moving to floor as the manual indicates it should.


My problem: The pedal is still very spongy. I suspect the rears are my problem. I ran the car up and down the drive way and can see good contact on the fronts but very little in the rear. The pads are removing the black coating on the rotors, very easy to see.

I have the rear of the car on jack stands.

I can continue to run fluid through the lines, but I feel like I am getting nowhere other than wasting good fluid.

Any suggestions?

 

[Jim Hodel]

When I installed the Stoptech front big brake system and SS lines on all fours on my 99 GTS, I had the front and rear in the air and started manual bleeding on the right rear, moved to the left rear, then the right front and then the left front.

The pedal is nice and firm but it took a few cycles.

On my Z28 track car, I need to sometimes bleed the master cylinder by manually (wifey) pressing on the brake pedal while I crack open the lines connected to the master cylinder (using a towel to catch the brake fluid) I also bleed the ABS unit which has bleed valves on the unit.

Not sure how that works on my Viper as I got the air out right away. FWIW, I think it is natural for the rears to move less fluid since they provide much less of the braking force.

I assume that you have checked all the brake line connections.

Jim

 

[VIPER BAZ UK]

I have always been told to work from the caliper further away from the master and work to the closest..
Just done a SRT-10 fronts and Gen2 fronts on the rear pedal is nice and solid...
All done manually

 

[Tom F&L GoR]

If you still have the OEM rear calipers, even with ABS they include the parking brake. Therefore the caliper has a larger than usual cavity inside that incorporates the mechanical parts of the parking brake to engage, disengage, and take up the slack when the pads wear. These little pieces easily hold on to air bubbles, frequently purchasers of 40mm non-ABS calipers have to go for a short drive to jiggle the bubbles loose. Otherwise, try kicking the brake pedal while bleeding and yank on the parking brake handle also. One smart guy had success running the rear wheels (engine on, in gear, up on jacks) to get the last of the air out. Good luck!

 

[ViperBite]

FOUND THE PROBLEM.

Turns out another supplier issue. As I sat down staring at the rear brakes, I pulled the OEMs that I still had. I then laid them down and saw the freaken problem.

Of course then it dawned on me just how stupid I was during the install to not catch this error. I am pissed at myself more than anything else right now.

The freakin supplier sent me the parts inverted such that the bleed screw was on the bottom and NOT the top. So even though I installed according to the labeling on the brakes it was wrong. I have to now remove the parking brake system from the OEMs and transfer to the new Yellow Powdercoated system (that is supplied from one of our own) so that the bleed screw is ON TOP. I am so pissed at myself for not catching this at install. No, you cannot just swap left and right, you have to swap the parking brake setup.

I will be taking pics so that if you interested you can see the problem. Once you see it you will say, "Oh" and then "how did you miss that at install".

This has been the brake install from hell.

I have installed the brakes on this car at least 4 times now.

 

[snampro]

look at it this way, now you know the master cylinder and lines are clean...

 

[Steve-Indy]

Glad that you found the problem...BUT, remember...that if there is the slightest clance that your pressure bleeder introduced air into the MC and then the ABS controller...you CANNOT bleed the ABS controller without using a DRB III to cycle the ABS system on your 2002. Hopefully, the air was all at the rear corners...but, do be cautious on your first few trips.

 

[ViperBite]

I don't think it was the bleeder. As I said the supplier shipped the rear brakes in the wrong configuration.

Has anyone replaced the parking brake spring assembly on the rears. Seems straightforward but now I question everything.

 

[Tom F&L GoR]

Sometimes the bleeder screw and the brake hose can be swapped to make the left-right swap? Guess I need to look at ABS calipers.