MadProfessor8138
Well-Known Member
I wasn't quite sure which section to post this question to because of topic and aircraft so my apologies if it doesn't belong here.
So the topic for today is bleeding brakes and why I cant seem to do it on a 1978 Piper Tomahawk.
This brake system is driving me crazy and I can't figure out what I'm doing wrong.
The problem started with just the right brake on pilots side and is now the entire system left & right - pilot & passenger side.....due to me,I'll explain.
I've checked for leaks and cannot find any..
1st attempt at bleeding right side,left side is good at this point :
1.Hooked a pressure bleeder to right caliper and opened the bleeder valve.
2. Applied pressure to system
3. Pumped both right toe brakes....no pressure in cylinders
4. Noticed reservoir on firewall was overflowing.
5. Stopped bleeding
2nd attempt at bleeding right side,left still good at this point.
1. Ran tubing from right caliper to resevoir on firewall
2. Cracked bleeder and let it gravity bleed for a few minutes,fluid was flowing and then stopped
3. Pumped both right pedals to try to get fluid flowing again
4. Got fluid flowing and pedal felt great then a big purge of air would come out and pedal would go to mush again
5. Pumped more and fluid was flowing and it seemed all the air was out but couldnt get a firm pedal
6. Stopped pumping right pedals and decided to pump parking brake
7. Pumped parking brake and could get any pressure
8. Now left brake is mush when it was rock hard.
9. Quit for the day
3rd attempt at bleeding,all pedals and emergency brake are mush................this is the recommended method in the Piper manual :
1. Ran lines from both calipers to resevoir on firewall
2. Pumped parking brake 50 times and locked it
3. Cracked right bleeder
4. Pumped both right pedals and fluid flowed
5. While pumping the pedals would firm up and purge a big shot of air and then turn to mush again
6. Shut down right side and did the same procedure to the left side
7. Shut left bleeder off
8. Pumped parking brake 25 times
9. Bled right and left calipers again
10. Pedals & parking brake are mush
11. Quit for the night
4th attempt to bleed,all pedals and parking brake are mush :
1. Tubing on both calipers running to resevoir on firewall
2. Pumped both right pedals while someone cracked right bleeder and shut bleeder down for me to pump it up again
3. Started getting good pedal and then would purge a shot of air and pedals would go to mush again
4. Bled both sides the same way and couldn't get a good pedal
5. Stopped for the day
Soooo......I've tried :
1.From caliper up with pressure
2. Gravity bleeding by pumping the pedals
3. Gravity bleeding per Piper with the emergency brake in use
4. Gravity bleeding with pedals and someone working the bleeders
The pedals are mush and will only firm up before spitting out a shot of air !!!!
What am I doing wrong ???
I've had brake systems be difficult but this is pure madness.....
I went and bought a suction bleeder in hopes that my 5th attempt will work out better.
The suction bleeder will pull fluid from the reservoir to the caliper.....
Kevin
So the topic for today is bleeding brakes and why I cant seem to do it on a 1978 Piper Tomahawk.
This brake system is driving me crazy and I can't figure out what I'm doing wrong.
The problem started with just the right brake on pilots side and is now the entire system left & right - pilot & passenger side.....due to me,I'll explain.
I've checked for leaks and cannot find any..
1st attempt at bleeding right side,left side is good at this point :
1.Hooked a pressure bleeder to right caliper and opened the bleeder valve.
2. Applied pressure to system
3. Pumped both right toe brakes....no pressure in cylinders
4. Noticed reservoir on firewall was overflowing.
5. Stopped bleeding
2nd attempt at bleeding right side,left still good at this point.
1. Ran tubing from right caliper to resevoir on firewall
2. Cracked bleeder and let it gravity bleed for a few minutes,fluid was flowing and then stopped
3. Pumped both right pedals to try to get fluid flowing again
4. Got fluid flowing and pedal felt great then a big purge of air would come out and pedal would go to mush again
5. Pumped more and fluid was flowing and it seemed all the air was out but couldnt get a firm pedal
6. Stopped pumping right pedals and decided to pump parking brake
7. Pumped parking brake and could get any pressure
8. Now left brake is mush when it was rock hard.
9. Quit for the day
3rd attempt at bleeding,all pedals and emergency brake are mush................this is the recommended method in the Piper manual :
1. Ran lines from both calipers to resevoir on firewall
2. Pumped parking brake 50 times and locked it
3. Cracked right bleeder
4. Pumped both right pedals and fluid flowed
5. While pumping the pedals would firm up and purge a big shot of air and then turn to mush again
6. Shut down right side and did the same procedure to the left side
7. Shut left bleeder off
8. Pumped parking brake 25 times
9. Bled right and left calipers again
10. Pedals & parking brake are mush
11. Quit for the night
4th attempt to bleed,all pedals and parking brake are mush :
1. Tubing on both calipers running to resevoir on firewall
2. Pumped both right pedals while someone cracked right bleeder and shut bleeder down for me to pump it up again
3. Started getting good pedal and then would purge a shot of air and pedals would go to mush again
4. Bled both sides the same way and couldn't get a good pedal
5. Stopped for the day
Soooo......I've tried :
1.From caliper up with pressure
2. Gravity bleeding by pumping the pedals
3. Gravity bleeding per Piper with the emergency brake in use
4. Gravity bleeding with pedals and someone working the bleeders
The pedals are mush and will only firm up before spitting out a shot of air !!!!
What am I doing wrong ???
I've had brake systems be difficult but this is pure madness.....
I went and bought a suction bleeder in hopes that my 5th attempt will work out better.
The suction bleeder will pull fluid from the reservoir to the caliper.....
Kevin
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