[Mrfixxit7]

Asking for some expert opinion out there.
I had my calipers off my vehicle for a few weeks (while they were getting powder coated. I installed the calipers and power bled the brakes and they were still mushy. I tried the old two person method and it helped but it was still mushy. I used a scan tool to cycle the ABS and it is still mushy. today I went to a local shop and they said that bench bleeding the master cylinder should take care of the issue.
Do you agree? Have any other recommendations?
Thanks in advance.

[Alpha1BC]

It's possible that you might need to bleed the master cylinder. Have a few questions for you first to better understand the situation:

1) How were the brake lines stored while the calipers were off? Were they just left to hang and gravity drain or did you get something to put the banjo bolts in and "plug" the system?

2) Did the fluid reservoir drain completely at any point?

3) Which power bleeder did you use? Motive?

4) With the scan tool, did the ABS pump cycle on each corner as you bled? When it cycled, did you hear the pump go on and then cycle between pressurized and non-pressurized (i.e., did it cycle between sounding strained and not strained)?

5) Did you bleed both valves on each caliper? If yes, what order did you bleed them?

6) How much fluid have you put through the system so far?

[wildchevy]

when bench bleeding a master never bottom out the piston, it will cut the seals on it as it moves past the ports.

[Mrfixxit7]

Originally Posted by Alpha1BC

It's possible that you might need to bleed the master cylinder. Have a few questions for you first to better understand the situation:

1) How were the brake lines stored while the calipers were off? Were they just left to hang and gravity drain or did you get something to put the banjo bolts in and "plug" the system?

2) Did the fluid reservoir drain completely at any point?

3) Which power bleeder did you use? Motive?

4) With the scan tool, did the ABS pump cycle on each corner as you bled? When it cycled, did you hear the pump go on and then cycle between pressurized and non-pressurized (i.e., did it cycle between sounding strained and not strained)?

5) Did you bleed both valves on each caliper? If yes, what order did you bleed them?

6) How much fluid have you put through the system so far?

Alpha.
1. I plugged the lines with rubber stoppers.
2.The master reservoir was never below the min level.
3. Yes Motive
4. The scan tool had several options and it did cycle the ABS at all four corners
5. Yes bleed according to the manual (inner then outer) RR, LF, LR, RF. Then I tried RR,LR, LR, RF.
6. I have gone through 4 bottles of Motul.

[Alpha1BC]

Originally Posted by Mrfixxit7

Alpha.
1. I plugged the lines with rubber stoppers.
2.The master reservoir was never below the min level.
3. Yes Motive
4. The scan tool had several options and it did cycle the ABS at all four corners
5. Yes bleed according to the manual (inner then outer) RR, LF, LR, RF. Then I tried RR,LR, LR, RF.
6. I have gone through 4 bottles of Motul.

Ok, in that case I don't think you'd need an actual bench bleed. Bench bleeding is typically only needed when you have a completely dry master cylinder or you accidentally drain the reservoir. Since the ABS system bleed didn't work, my thoughts are it's possible you might have had some air creep up the brake lines to the master cylinder while the car was sitting. Not sure if you have access to the manual or not, but the procedure for bleeding the MC are similar to manual bleeding on the caliper, just make sure you have lots of rags and water on hand to clean up and spilled fluid

1) Have someone slowly press the brake pedal
2) With a rag under the master cylinder, loosen the front brake line port
3) while fluid is still flowing out before the pedal reaches the floor, tighten the front brake line port.
4) have your helper slowly release the brake pedal
5) Wait 10-20 seconds and repeat steps 1-3 on the front brake line port until there is no air coming out
6) Repeat everything above for the rear MC port.

After all that, you'll want to re-do the caliper/ABS bleed again since there's a chance you're pushing air into the lines again that will need to work their way out of the system. For reference, the whole system takes about 1L of fluid, so you should hopefully be able to get all the bubbles out with less than that.

[Mrfixxit7]

Alpha,
Thanks for all the info. I will give it a try this weekend.

[hammdo]

Speed bleeders can make this a one man job. I have them. I actually do a vacuum bleed:
https://www.camaro5.com/forums/showp...postcount=1986

(I do have the motive but like the vacuum better);

http://www.speedbleeder.com/size.htm

SB1010S Is what I used on my 5th gen ZL1 brakes, standard size for quite some time...

-Don

[Mrfixxit7]

I figured out what my issue was. I made a rookie mistake, I installed the front calipers on the wrong side, the bleeder valve needs to be pointed up. I swapped them around and it works great now.