No Brake peddle pressure
08-12-2014, 12:49 PM
#31
Rennlist Member
Thread Starter
I must say this has been one of the most frustrating efforts I have experienced in the past 5 years.
I am wondering if the MC needs to be replaced? It's one thing to be able to see what the problem is and another to struggle with this one. Monterey is looming, got to get it resolved....Sure wish Andre was still around. Robin Williams brought this up.
I am wondering if the MC needs to be replaced? It's one thing to be able to see what the problem is and another to struggle with this one. Monterey is looming, got to get it resolved....Sure wish Andre was still around. Robin Williams brought this up.
08-12-2014, 06:03 PM
#33
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Depends on what you are vacuuming.
If you are pulling vacuum from the caliper end, reservoir cap can be on or off. I leave it on if I don't have the pressure bleeder attached, just so junk doesn't accidentally get into the resrevoir.
There is no way to pull vacuum on the master cylinder itself.
I applied vacuum (with a vacuum pump, not the little hand pump) to the high end of each line, then allowed/pushed fluid in from the caliper end, until I worked my way up to the lines where they attach to the ABS unit. I pulled air out of then fluid into the ABS unit. The lines from the MC to the ABS unit were filled pushing from the MC end, after bench-bleeding the MC itself. The air bubbles want to float uphill, so use that to your advantage. Push fluid from the bottom towards evacuated sections higher up. Vacuum causes any bubbles to grow, making them more likely to move towards the higher spots in the system. If your vacuum is applied at each high spot along the way, it will pull the bubbles out.
Do Not Operate the Master Cylinder to test your work part way through the process. You risk pumping more air in.
I should have set up the video camera to detail all the fun I had getting the last bit air out. Lines were easy, ABS unit was the challenge.
If you are pulling vacuum from the caliper end, reservoir cap can be on or off. I leave it on if I don't have the pressure bleeder attached, just so junk doesn't accidentally get into the resrevoir.
There is no way to pull vacuum on the master cylinder itself.
I applied vacuum (with a vacuum pump, not the little hand pump) to the high end of each line, then allowed/pushed fluid in from the caliper end, until I worked my way up to the lines where they attach to the ABS unit. I pulled air out of then fluid into the ABS unit. The lines from the MC to the ABS unit were filled pushing from the MC end, after bench-bleeding the MC itself. The air bubbles want to float uphill, so use that to your advantage. Push fluid from the bottom towards evacuated sections higher up. Vacuum causes any bubbles to grow, making them more likely to move towards the higher spots in the system. If your vacuum is applied at each high spot along the way, it will pull the bubbles out.
Do Not Operate the Master Cylinder to test your work part way through the process. You risk pumping more air in.
I should have set up the video camera to detail all the fun I had getting the last bit air out. Lines were easy, ABS unit was the challenge.
08-12-2014, 08:42 PM
#34
Rennlist Member
Thread Starter
I put the car back on it's feet and since I live on a hill, and now that my E brake works,
drove the car down the hill very carefully. As I drove it I got enough peddle to stop the car and never had to use the E brake. Now I am going to try and bleed it again.
I know this is a goofy way to do it but desperate men do desperate things in desperate times.
drove the car down the hill very carefully. As I drove it I got enough peddle to stop the car and never had to use the E brake. Now I am going to try and bleed it again.
I know this is a goofy way to do it but desperate men do desperate things in desperate times.
08-13-2014, 08:34 PM
#35
Rennlist Member
Thread Starter
GOT IT!!!!!!!!
What I did not do correctly was when I changed out the rear brake line for I took off the outboard rubber lines but not the inboard ones!
Rookie error
Van
What I did not do correctly was when I changed out the rear brake line for I took off the outboard rubber lines but not the inboard ones!
Rookie error
Van
08-13-2014, 09:02 PM
#37
Nordschleife Master
Hopefully, you'll have this mastered for when you do this all over again for your S conversion 
08-13-2014, 10:23 PM
#38
Rennlist Member
Congrats! Now you can go to Monterey. Glad you got it worked out and come by and see Mark and I at Werks if you can. He is showing his primo white 928.
