Air in brake system still?

[roger1]

'83 El Camino.

I just finished a front-end brake job with new master cylinder too.
Master is a new AC Delco unit.
On the front I installed new calipers, pads and rotors. It's a Power Stop Z26 w/caliper kit.
Rear brakes were in still good shape and no need to do anything there.

I bench bled the master using the older method using tubes and was certain I got all the air out. When the bubbles stopped appearing, I changed the angles of the unit a few times and also slightly tapped on it to see if I could coax any more air out of it. I felt I pumped it even more than I needed to just to make sure there wasn't.

First thing I did when everything was installed back on the car was to flush the entire system. I used a bleeding kit and a vacuum pump and sucked fluid through at all 4 locations until all the fluid coming out looked fresh and new. Never came close to running the master dry. Checked it often during the process.

After doing this I checked the pedal to see if I had any and there wasn't so I knew I needed to bleed them the conventional way. Got my wife out there to help.
I went around the car twice with her pumping the brakes and I felt we did enough bleed cycles at each wheel to certainly get all the air out. Again, never came close to running the master dry.

Just took it for a test drive and the brakes feel kind of squishy. I could lock the brakes up but barely and I was pushing down just about as hard as I could.

I've done this kind of job many times over the years and I almost never have had a problem getting all the air out on a new brake system. I can think of only once.
And btw, I didn't like how the brakes felt before I did this job either. Kind of a little of the same feeling but not as bad.

I'd appreciate any advice on where to go from here.

 

[pontiacgp]

when bleeding the brakes did you start with the wheel furthest from the master and work your way towards the one closest?

 

[roger1]

Yes. RR,LR,RF,LF

 

[roger1]

Another btw.
The vacuum booster is the 35 year old original and the car has 75K miles on it.

 

[pontiacgp]

if you pump the pedal does it become firmer or stay the same?

 

[roger1]

I didn't try that so I'd have to test drive again.

Btw, I had a 2 PM appointment at my alignment shop for a front-end alignment.
I called them back and asked if they do brakes and whether they have a power bleeding system. They said yes and no problem to look at this while I'm there.

Time is getting close for me to leave for there so I can't answer your question now.
I'll report back with what happens at the shop after I get back

 

[Longroof79]

Power bleeding should take care of it, although I never had to rely on that method.
I usually use my trusty Mity-Vac...or even a piece of hose in a jar partially filled with brake fluid.
However, I've gotten good results using speed bleeders. They never failed me.

 

[pontiacgp]

Power bleeding should take care of it, although I never had to rely on that method.
I usually use my trusty Mity-Vac...or even a piece of hose in a jar partially filled with brake fluid.
However, I've gotten good results using speed bleeders. They never failed me.

He bench bled the new master then used the vacuum method which works well and then bled it again the conventional way so it sounds like he did everything correctly. I asked about if a few pumps gave him a better peddle to see if it is air or possibly a defective master. I don't think there is a problem with the proportional valve since the rears bled with the conventional method.

 

[Longroof79]

He bench bled the new master then used the vacuum method which works well and then bled it again the conventional way so it sounds like he did everything correctly. I asked about if a few pumps gave him a better peddle to see if it is air or possibly a defective master. I don't think there is a problem with the proportional valve since the rears bled with the conventional method.

Yeah Steve, it does sound like he covered all his bases. Even an air bound system should have freed up by now.
I think proportioning valves, or combo valves rarely get compromised.

 

[roger1]

Thanks for the help guys!
He got it pressured up and re-bled while I watched. Same rotation sequence starting at the RR.
No air until the RF. Just a touch when he opened it. LF was good.
That made all the difference. Feels solid now.

I haven't done another lock-up test yet. I had totally forgotten that there was a break-in procedure for these ceramic pads. Didn't think of it until I was at his shop. I forgot because I bought this brake kit a couple of months ago but didn't install until now.
I need to read the instructions again and I'll take it back out and do it.
I hope it wasn't detrimental to the pads that I've already driven with them for 10 to 15 miles without doing the procedure.

Btw. I had rebuilt the front end on this car using all Moog Problem Solver parts. That's why I needed this alignment. (I think he did a good job on it as it feels so much better than it did with my guesstimate settings.)
Today is the first day the car has been on the road in a year. Gave it a new paint job too. I need to change my avatar. The car is now white.

One last question as you guys seem pretty experienced with brakes.
With 35 years and 75K miles on my original vacuum booster, I am on borrowed time with it and should think about replacing, or let it go and just don't think about it unless I have any trouble with it?