vanster

Ok...
One more part of my brake saga...learning learning.
Now that my brakes are all in, including new e brake shoes, I cannot get any peddle pressure.

This is what I have done:
New pads in the rear including E brake shoes. All went together Ok
Not easy but got everything back in and the rotors turn freely. New SS brake lines
New sensors. Front, drivers left pads were a struggle but go them in and the rotor will turn but not all that free.
Front right I could not get the caliper on with the new pads no matter how hard I struggled.
I used an old set of not so worn pads. Life is good.
New rebuild kits on both fronts + SS lines and sensors.
Used a power bleeder at 20# and bleed all 4 corners twice to make sure I got all the bubbles out. OK so far.
Left the power bleeder connected for 20 min or so at 20psi to see if there was a drop. All Ok

Start the car and the peddle goes to the floor. Went back and re-bleed. Same result.

What did I miss?

Bilal928S4

When you pump the peddle does it come up? Yes I know when you press it once it goes to the floor, you have to use your hand and see if stiffens up after you pump it.
Now that really sounds just wrong.

vanster

I can pump it to death and the pressure is still the same. It doesn't stick to the floor where I have to reach in and pull it back. At first it seems to have just a bit of pressure but I can still push it against the firewall. The clutch peddle is Ok, and I bleed it as well

vanster

Bled it as well...sorry about that

dr bob

So the double top secret secret is to plug/cap the brake lines when changing hoses. Keeps the system full of fluid while you mess around with stuff. If the ends are left open, the fluid will drain completely out.

On my '89 with ABS, I ended up vacuum bleeding and pressure filling each leg from the caliper end. At some point during the annual fluid replace history, I'd managed to get some air in the system, and it was stubbornly hanging out in a high spot someplace. Normal pressure bleeding wouldn't move the air out. Normal pedal bleeding was better but still not enough. Ultimately, pushing/pulling fluid from the lowest end of each section towards the high spots was what got the job done.

I used a good vacuum pump at the ABS pump connections, and sucked as much air out as I could. Then filled from the caliper end. Took the best part of the afternoon but have a nice firm high pedal again.

Nicole

FWIW, I was told the factory fills the brake systems by first applying vacuum, then letting the fluid in..

vanster

Nicole
How the heck do you this?

vanster

Dr Bob
An older non ABS system appears to be simple. More or less a push and release.
Is there somewhere in the system that causes a bubble and how does one push it through. Monterey is this Friday

The Forgotten On

Could you have blown out the seals in the master cylinder?

vanster

Good question. The MC is new and I only started out with 10#
How can you tell?

vanster

No brake fluid is leaking anywhere, that I can see anyway. Could it be that one of the seals that I replaced in one of the pistons was done incorrectly?

vanster

bump

Pfc. Parts

The first thing that caught my eye was the problem you had getting the new pads in on the front right, that doesn't sound right.

I just did the dsame thing you did on my 85 and (not knowing the double top secret until after the fact) ended up draining the entire system during the caliper rebuild and SS line replacement. I believe I bled the entire system 6 times before I had all the air out. I did use a pressure bleeder but didn't use the vacuum technique mentioned by Dr. Bob and I was able to completely restore hydraulics. My car is not equipped with ABS, which is why I ask the MY. I believe Dr. Bob's experince involved ABS.

Another Double Top Secret is the bleeding sequence on these cars is exactly opposite the standard procedure; you bleed the caliper NEAREST the Master Cylinder first.

vanster

I just bought a vacuum bleeder from Harbor Tool for $25. I now understand what I ( we ) got ourselves into. One positive note is that this is good ab exercise if your car is on jack stands..... I need to buy more Dot 4

SteveG

The order is not reversed. Passenger rear, driver rear, passenger front, driver front, clutch slave. Having the front slightly higher might also help. If the system was drained totally you will most likely have to do the clutch master as well, do it last, it is the one that will challenge your acrobatic skills. If all the parts are new and the parts are tight, it will work. I use a Motronic and about 10 psi, it doesn't take much pressure, in fact working slowly is better b/c the bubbles need time to find their way.