More Brake Woes
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
As you have found, there are very specific procedures to use when working on the brake system. If the distribution valve gets shifted off-center (due to system leak), it needs to be reset to center B4 bleeding.
M/C needs to be bench-bled; repairs made to lines, etc; system needs to be bled in specific order [I prefer from 'nearest-to-farthest' sequence].
You eventually got to this process. Glad it is finally tight!
M/C needs to be bench-bled; repairs made to lines, etc; system needs to be bled in specific order [I prefer from 'nearest-to-farthest' sequence].
You eventually got to this process. Glad it is finally tight!
Le Mans Master
Joined: Jan 2001
Posts: 6,743
Likes: 1,385
Care to share a picture of this tool? Or where you got it? I'm more curious than anything else.
Glad you got it all fixed
Glad you got it all fixed
The warning light is out. I inserted the special tool in the combination valve and rebled all four calipers again. No air bubbles. Replaced the tool with the warning switch. Turned the key and no light. Pushed the pedal and the light didn't come on. Could it possibly be fixed?
Test drive next...
Test drive next...
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
Thread Starter
Le Mans Master
Joined: Aug 2010
Posts: 5,339
Likes: 546
From: Central Texas
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
Yep. Thar she be matey. A lot better picture than I have. The point on the bottom of the tool does not move up / down like the brake warning switch does. POL I beleive was Performance OnLine? Maybe. About $12.
And no, brake fluid does not flow out when you change from the switch to the tool and back again. Unless something is severly wrong with the Prop Valve.
You can see the five brakeline ports on the Prop Valve. Two lines coming in from the master, and three lines going out to the calipers. And you can clearly see the big spring on the front side pushing on the piston. The two holes are for the bolts to the frame and the right side port in the photo is for line to the rear brakes.
And no, brake fluid does not flow out when you change from the switch to the tool and back again. Unless something is severly wrong with the Prop Valve.
You can see the five brakeline ports on the Prop Valve. Two lines coming in from the master, and three lines going out to the calipers. And you can clearly see the big spring on the front side pushing on the piston. The two holes are for the bolts to the frame and the right side port in the photo is for line to the rear brakes.
Last edited by HeadsU.P.; May 22, 2018 at 07:22 AM.
Thread Starter
Le Mans Master
Joined: Aug 2010
Posts: 5,339
Likes: 546
From: Central Texas
Test drive this morning.
Hard pedal and no light.
I'm officially calling this job FINISHED!
The culprits in this case were VERY small leaks. One at a LR caliper seal. Also a leak at the combination valve where the crossover line attaches. These were allowing air into the system and causing a pedal that went to the floor.
No amount of bleeding would correct the problem until the leaks were fixed.
Thanks to all who responded. You guys are awesome.
On to the next project...
Hard pedal and no light.
I'm officially calling this job FINISHED!
The culprits in this case were VERY small leaks. One at a LR caliper seal. Also a leak at the combination valve where the crossover line attaches. These were allowing air into the system and causing a pedal that went to the floor.
No amount of bleeding would correct the problem until the leaks were fixed.
Thanks to all who responded. You guys are awesome.
On to the next project...
Burning Brakes
Joined: May 2017
Posts: 774
Likes: 375
From: Seattle WA
Test drive this morning.
Hard pedal and no light.
I'm officially calling this job FINISHED!
The culprits in this case were VERY small leaks. One at a LR caliper seal. Also a leak at the combination valve where the crossover line attaches. These were allowing air into the system and causing a pedal that went to the floor.
No amount of bleeding would correct the problem until the leaks were fixed.
Thanks to all who responded. You guys are awesome.
On to the next project...
Hard pedal and no light.
I'm officially calling this job FINISHED!
The culprits in this case were VERY small leaks. One at a LR caliper seal. Also a leak at the combination valve where the crossover line attaches. These were allowing air into the system and causing a pedal that went to the floor.
No amount of bleeding would correct the problem until the leaks were fixed.
Thanks to all who responded. You guys are awesome.
On to the next project...
2 Quick questions:
1) How did you diagnose the leak at the junction block?
2) Did your brakes slowly sink to the floor all the way? Mine is soft then seems solid like the last 1".
This was a great thread that is going to help a lot of people!!!
Thread Starter
Le Mans Master
Joined: Aug 2010
Posts: 5,339
Likes: 546
From: Central Texas
Originally Posted by scottjamison
Congrats buddy!!!!!
2 Quick questions:
1) How did you diagnose the leak at the junction block?
2) Did your brakes slowly sink to the floor all the way? Mine is soft then seems solid like the last 1".
This was a great thread that is going to help a lot of people!!!
2 Quick questions:
1) How did you diagnose the leak at the junction block?
2) Did your brakes slowly sink to the floor all the way? Mine is soft then seems solid like the last 1".
This was a great thread that is going to help a lot of people!!!
I replaced the combination valve. I figured it was 37 years old so why not. The fitting from the crossover line to the valve was simply seeping. I mistook the very small drip on the driveway to be from the master cylinder. The valve is almost directly under the mc. So I tightened the fitting more. More of a leak developed then. I could probably have saved myself from replacing the brake line if I knew about the copper washers that I posted above.
2.
Yes the pedal would be soft and go to the floor.
Thanks for the kudos on the thread. I hope it does help some people out with the pesky C3 brake system.
Last edited by Street Rat; May 22, 2018 at 01:07 PM.
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Melting Slicks
Joined: Jul 2005
Posts: 2,649
Likes: 863
Street Rat - Glad you finally got it !!! Dealing with two simultaneous problems (the bad caliper seal and the leak at the valve) always makes things harder to figure out and fix, but you got there... That is what matters !!!
scottjamison - The pedal feeling a bit mushy up top but solid at the bottom is a classic sign that you have air in part of the system. You should have a dual piston Master cylinder - they are the norm - and their purpose in life is to make sure that if you have a failure in part of the braking system - you won't lose ALL your braking power. When one piston in the master cylinder moves quite easily - the other piston basically operates the other half of the braking system. So - do a full bleed and see how it feels - (I'd start with bleeding the fronts but thats just a partially educated guess as to where the problem lies...) of course - if there is some air in the system - you have to figure out how it got in there - and that typically means a leaky seal or a bad line somewhere.... so look for brake fluid seepage/ drips while bleeding....
scottjamison - The pedal feeling a bit mushy up top but solid at the bottom is a classic sign that you have air in part of the system. You should have a dual piston Master cylinder - they are the norm - and their purpose in life is to make sure that if you have a failure in part of the braking system - you won't lose ALL your braking power. When one piston in the master cylinder moves quite easily - the other piston basically operates the other half of the braking system. So - do a full bleed and see how it feels - (I'd start with bleeding the fronts but thats just a partially educated guess as to where the problem lies...) of course - if there is some air in the system - you have to figure out how it got in there - and that typically means a leaky seal or a bad line somewhere.... so look for brake fluid seepage/ drips while bleeding....
Burning Brakes
Joined: May 2017
Posts: 774
Likes: 375
From: Seattle WA
Street Rat - Glad you finally got it !!! Dealing with two simultaneous problems (the bad caliper seal and the leak at the valve) always makes things harder to figure out and fix, but you got there... That is what matters !!!
scottjamison - The pedal feeling a bit mushy up top but solid at the bottom is a classic sign that you have air in part of the system. You should have a dual piston Master cylinder - they are the norm - and their purpose in life is to make sure that if you have a failure in part of the braking system - you won't lose ALL your braking power. When one piston in the master cylinder moves quite easily - the other piston basically operates the other half of the braking system. So - do a full bleed and see how it feels - (I'd start with bleeding the fronts but thats just a partially educated guess as to where the problem lies...) of course - if there is some air in the system - you have to figure out how it got in there - and that typically means a leaky seal or a bad line somewhere.... so look for brake fluid seepage/ drips while bleeding....
scottjamison - The pedal feeling a bit mushy up top but solid at the bottom is a classic sign that you have air in part of the system. You should have a dual piston Master cylinder - they are the norm - and their purpose in life is to make sure that if you have a failure in part of the braking system - you won't lose ALL your braking power. When one piston in the master cylinder moves quite easily - the other piston basically operates the other half of the braking system. So - do a full bleed and see how it feels - (I'd start with bleeding the fronts but thats just a partially educated guess as to where the problem lies...) of course - if there is some air in the system - you have to figure out how it got in there - and that typically means a leaky seal or a bad line somewhere.... so look for brake fluid seepage/ drips while bleeding....
Yes I just replaced the ENTIRE system as part of my upgrade and have a dual MC. We have bled it several times, so now I am going to start looking for tiny leaks ala Street Rat. I did notice that when the MC cover is off and I pump the pedal, the front squirts up in the air a little but the back does not. I don't know if that means anything, I just noticed it.
This weekend I will back it up my driveway just to give a final incline MC bleed (I have a steep assed driveway) then I cleaned my garage floor really good today while it is getting the sweet exhaust system built for it and I will start looking for drips. I also want to try resetting the porportioning valve just in case. I already have the tool.
Last edited by scottjamison; May 22, 2018 at 06:02 PM.