Brake light comes on and bleeder screws won't turn
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Bobs rare 6
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- Apr 11, 2004
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Time for a hydro-boost David!
Heh. I was going to suggest that.
Yeah Bob I'm about ready for one, just wished I could find one that is complete ready to drop in and go and that doesn't cost a fortune.
Well my nephew and I just got thru trying to re-bleed this thing.
We bled all 4 corners starting with the RR, then LR. then RF then LF last. Each time using a reverse bleeder kit. I think we had to suck out the MC reservoir at least 4 times with a turkey baster.
A C clamp was placed over the prop valve to keep the pin in even though I don't know if it's required on a reverse bleed. I have heard it's required on the 2 man pressure bleed.
During the reverse bleed we took turns...one watched the MC while the other worked the bleeder. No air bubbles popped up thru the MC the whole time.
However I did notice when we bled the rears, fluid was coming up thru the rear bowl of the MC and some was coming up on the front side. Is this normal? Or does this indicate some sort of internal leak?
However when we did the fronts fluid only came up thru the rear bowl (that I could see) but not the front.
Once all this was done then I let the accumulator/motor cycle thru at least 3 times until I saw no more air bubbles in the motor side of the PM's reservoir.
Well so far at 1:30 am the darn brake light is still doing it's thing. The pedal feels slightly better in terms of firmness but not much. I've yet to test drive this thing but I can almost guarantee it will not be stopping any better than it has before.
I'm beginning to wonder if the PM MC has some sort of an internal leak in which fluid is bypassing the seals and thus not creating the correct pressure output required....has anyone ever had this issue?
We bled all 4 corners starting with the RR, then LR. then RF then LF last. Each time using a reverse bleeder kit. I think we had to suck out the MC reservoir at least 4 times with a turkey baster.
A C clamp was placed over the prop valve to keep the pin in even though I don't know if it's required on a reverse bleed. I have heard it's required on the 2 man pressure bleed.
During the reverse bleed we took turns...one watched the MC while the other worked the bleeder. No air bubbles popped up thru the MC the whole time.
However I did notice when we bled the rears, fluid was coming up thru the rear bowl of the MC and some was coming up on the front side. Is this normal? Or does this indicate some sort of internal leak?
However when we did the fronts fluid only came up thru the rear bowl (that I could see) but not the front.
Once all this was done then I let the accumulator/motor cycle thru at least 3 times until I saw no more air bubbles in the motor side of the PM's reservoir.
Well so far at 1:30 am the darn brake light is still doing it's thing. The pedal feels slightly better in terms of firmness but not much. I've yet to test drive this thing but I can almost guarantee it will not be stopping any better than it has before.
I'm beginning to wonder if the PM MC has some sort of an internal leak in which fluid is bypassing the seals and thus not creating the correct pressure output required....has anyone ever had this issue?
It sounds like you have an internal leak in the master cylinder if you are exchanging fluid between the front and rear bowls. Your bleeding method sounds great and it sounds like you have done everything by the book.
I would PM the expert on these systems, Zeus87gn
I would PM the expert on these systems, Zeus87gn
Thanks...and an update
So today I decided to try out the car (test drive) the first time since my nephew and I did the brakes late Friday night. Interestingly enough the brake light is still doing it's thing, yet the brakes feel better. At 45-50 mph I was able to slam on the brakes and lock them up and even skid a little. Tried it a few more times going faster...got up to at least 80 mph....didn't lock them or skid but it stopped the car ok....did send me forward. Repeated this a few more times....then all the sudden I get smoke pouring from both front brakes. Hhmmm....are they working a bit better? Maybe it's the VGX pads aren't up to snuff?
So now that has me wondering if maybe just the prop valve lamp switch is finicky or what....
So today I decided to try out the car (test drive) the first time since my nephew and I did the brakes late Friday night. Interestingly enough the brake light is still doing it's thing, yet the brakes feel better. At 45-50 mph I was able to slam on the brakes and lock them up and even skid a little. Tried it a few more times going faster...got up to at least 80 mph....didn't lock them or skid but it stopped the car ok....did send me forward. Repeated this a few more times....then all the sudden I get smoke pouring from both front brakes. Hhmmm....are they working a bit better? Maybe it's the VGX pads aren't up to snuff?
So now that has me wondering if maybe just the prop valve lamp switch is finicky or what....
Based on your description, it sounds like your brakes are solid but the fact that the light comes on a lot is a bit of a concern. I have no doubt you have all of the air out of the system given the hours you have spent bleeding the lines and accumulator. Have you actually taken the plastic nut off of the proportioning valve and done the reset procedure on it? I am wondering if you are getting an intermittent ground on the valve switch causing your brake light to illuminate.
3.8,
Reverse bleeding does nothing except flush fluid and any contaminants back into the master cylinder where they may cause some damage. If it gets air out, I really can't knock it. But I have never tried it. Just remember, the fluid and the system wasn't designed to work or be bled like that. That's why the bleeder screws are on the wheels.
The fluid coming back into the master cylinder during this reverse bleed proves nothing for an internal leak. The main division seals in the master are a cup seal and will seal perfectly only in one direction. The other direction fluid will go right by.
Testing for internal leaks is real easy and only tests 2 things (which are the only ones of importance). 1 - the seal between the high pressure side and the low pressure side; and 2 - the seals in the main cylinder portion that actually make your brakes work.
For test 1: Once you feel confident there is no air in the system, pump the system down and than let the motor pump it up. While leaving the key on, and after the motor stops by itself time how long it takes for the motor to self cycle. That means just let it sit there while you watch the clock. Don't touch it. If it's less than 2 minutes it is considered to have an internal leak and needs work. Between 2 and 5 minutes it's just old. More than 5 minutes or you give up waiting you're fine.
For test 2: It's as mentioned eariler - Turn on the key with the system pumped up and push down on the pedal and see if it stays still or begins to sink to the floor. If it stays still, you're fine. If it sinks to the floor it's dying. The amount of pedal travel before the brakes grab doesn't mean much here. That's typically a factor of how well your rear brakes are adjusted, the condition of the sliders on your front calipers and the overall condition of the system.
You mentioned seeing bubbles coming in the rear port on the pressure side of the bowl during your cycling. If that is still so, you may still have air in your accumulator. Cycle it again. Pump it down and then look at the fluid. If it's frothy, let it sit until it clears up and they start over.
Sorry it took so long for me to reply.
Houston and Hell start with the same letter, and it's just about the same temp.
Z
Reverse bleeding does nothing except flush fluid and any contaminants back into the master cylinder where they may cause some damage. If it gets air out, I really can't knock it. But I have never tried it. Just remember, the fluid and the system wasn't designed to work or be bled like that. That's why the bleeder screws are on the wheels.
The fluid coming back into the master cylinder during this reverse bleed proves nothing for an internal leak. The main division seals in the master are a cup seal and will seal perfectly only in one direction. The other direction fluid will go right by.
Testing for internal leaks is real easy and only tests 2 things (which are the only ones of importance). 1 - the seal between the high pressure side and the low pressure side; and 2 - the seals in the main cylinder portion that actually make your brakes work.
For test 1: Once you feel confident there is no air in the system, pump the system down and than let the motor pump it up. While leaving the key on, and after the motor stops by itself time how long it takes for the motor to self cycle. That means just let it sit there while you watch the clock. Don't touch it. If it's less than 2 minutes it is considered to have an internal leak and needs work. Between 2 and 5 minutes it's just old. More than 5 minutes or you give up waiting you're fine.
For test 2: It's as mentioned eariler - Turn on the key with the system pumped up and push down on the pedal and see if it stays still or begins to sink to the floor. If it stays still, you're fine. If it sinks to the floor it's dying. The amount of pedal travel before the brakes grab doesn't mean much here. That's typically a factor of how well your rear brakes are adjusted, the condition of the sliders on your front calipers and the overall condition of the system.
You mentioned seeing bubbles coming in the rear port on the pressure side of the bowl during your cycling. If that is still so, you may still have air in your accumulator. Cycle it again. Pump it down and then look at the fluid. If it's frothy, let it sit until it clears up and they start over.
Sorry it took so long for me to reply.
Houston and Hell start with the same letter, and it's just about the same temp.
Z
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