A few brake caliper refinishing questions
#47
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Nicole:
From reading this, I am not completely sure how you are bleeding the system. Are you using any sort of pressure source like a Motiv bleeder ? If not, it makes this type of full system bleed much easier.
Also, if you allowed the system to drain, you may need to cycle the ABS system in order to get all of the air out. This requires the use of a Bosch KTS-300, i.e. "hammer" to diagnostically run the ABS valving during bleeding. If you cannot get access to a "hammer", plan on doing lots of follow up bleeding to get all the air.
As another helpful hint. While bleeding the Brembo style calipers, if they have been off the car and open, you should try lightly taping on the body of the caliper behind where the pistons are. The tapping helps loosen any bubbles lodged in the nooks and crannies of the caliper bores.
Hope to see you back on the road soon.
From reading this, I am not completely sure how you are bleeding the system. Are you using any sort of pressure source like a Motiv bleeder ? If not, it makes this type of full system bleed much easier.
Also, if you allowed the system to drain, you may need to cycle the ABS system in order to get all of the air out. This requires the use of a Bosch KTS-300, i.e. "hammer" to diagnostically run the ABS valving during bleeding. If you cannot get access to a "hammer", plan on doing lots of follow up bleeding to get all the air.
As another helpful hint. While bleeding the Brembo style calipers, if they have been off the car and open, you should try lightly taping on the body of the caliper behind where the pistons are. The tapping helps loosen any bubbles lodged in the nooks and crannies of the caliper bores.
Hope to see you back on the road soon.
#48
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What I don't get is, we did everything in the order Nicole described (and inside, then outside) and there were absolutely no bubbles in the fluid. We bled the master cylinder at the end. Also, no bubbles. There were no leaks of any kind to be found. The car too maybe 1/4 of a quart of brake fluid (well at least from my gathering, when added all together of what we put into the reservoir). I know that on some cars, you need to have the ignition on while bleeding, in order for the ABS system to be active (namely GM vehicles). It was all done in the old-fashioned sort of way. Next time we'll try I'm bringing my mighty-vac (the big one that holds a vacuum, not the little guy).
Anyway enough parentheses.
Anyway enough parentheses.
#49
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Lose the mighty vac. get a Power bleeder or whatever it is called that pumps up and fits into the reservoir. This is the 21st century. Nicole, if you want ot borrow mine, tell me and give me a day's notice so I can retrieve it from my garage.
#50
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FYI there was a recent thread on replacing the hoses on the power bleeders as they do not hold up well over time. I believe the OP had it explode brake fluid as he was using it.
Just a heads up.
Just a heads up.
#51
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Also, if you allowed the system to drain, you may need to cycle the ABS system in order to get all of the air out. This requires the use of a Bosch KTS-300, i.e. "hammer" to diagnostically run the ABS valving during bleeding. If you cannot get access to a "hammer", plan on doing lots of follow up bleeding to get all the air..
#53
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Yup, that was my bleeder hose that exploded spraying brake fluid all over the place and me. Be sure to have a new hose ready and also small hose clamps to secure your hose if you haven't used your power bleeder recently. The clear plastic hose will deteriorate over time. You should take Dr. Bob's advice and get some reinforced plastic hose from Home Depot to use as a replacement. Don't think it appears to be OK; just replace the original hose with the reinforced hose and save yourself a lot of grief.
#54
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#55
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after reading this I would suggest that you dont put any fluid into the power bleeder ( this is the one that attaches to the resivour and can be hand pumped).
Only fit the cap to the resivour and pump the tank up with the master resivour full, then open the bleeders in the correct sequence and the system should have all of the air expelled.
I would suggest that the pump pressure be kept at less than 12 PSI I use 10 no problems and no wasted fluid
Only fit the cap to the resivour and pump the tank up with the master resivour full, then open the bleeders in the correct sequence and the system should have all of the air expelled.
I would suggest that the pump pressure be kept at less than 12 PSI I use 10 no problems and no wasted fluid
#57
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after reading this I would suggest that you dont put any fluid into the power bleeder ( this is the one that attaches to the resivour and can be hand pumped).
Only fit the cap to the resivour and pump the tank up with the master resivour full, then open the bleeders in the correct sequence and the system should have all of the air expelled.
I would suggest that the pump pressure be kept at less than 12 PSI I use 10 no problems and no wasted fluid
Only fit the cap to the resivour and pump the tank up with the master resivour full, then open the bleeders in the correct sequence and the system should have all of the air expelled.
I would suggest that the pump pressure be kept at less than 12 PSI I use 10 no problems and no wasted fluid
I think if I were looking to just add air pressure on top of the fluid in the reservoir, I wouldn't bother with the pump at all. Just a short hose from the cap to an instrument regulator, then attach the shop air supply to it. I'd add a restriction in the hose fitting too, so total airflow would be limited.
On flushing through the ABS pump, I'm pretty sure that the Motiv will push fluid right through it. That little pump in there looks very similar to the PSD pump, so there's likely a way to power it up in short bursts to push any stray air from the chambers. I'm not near the car right now so no way to verify though.
#58
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I managed to blow a resivour off the master cylinder with about 20 PSI using shop air and a misreading regulator.
anyway to use the system thats adding fluid to the brakes seems less efficient and a lot more brake fluid will be exposed to outside air
anyway to use the system thats adding fluid to the brakes seems less efficient and a lot more brake fluid will be exposed to outside air
#59
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Are you guys saying that lots of flushing can clear any potential air out of the ABS system without the Hammer? Has anybody actually done this?
Could the ABS system be "de-bubbled" with a few "hard stops" that trigger the ABS?
We sure did not do it last time we took a caliper off...
Could the ABS system be "de-bubbled" with a few "hard stops" that trigger the ABS?
We sure did not do it last time we took a caliper off...
Last edited by Nicole; 09-30-2008 at 07:08 AM.
#60
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Nicole:
A key question in all this is whether or not you let the system drain when the calipers were removed.
If your system was let go to all air, it is not a matter of getting some bubbles removed but instead an issue of getting new fluid back into all areas of the system. If you look at all of the line junctions as well as the ABS, there needs to be lots of fluid movement with disturbance to get everything bled. If you can get a pressure bleeder to hold pressure and not leak around 10+ psi, the bubble removal goes much better.
Patience is much needed when doing this task...
A key question in all this is whether or not you let the system drain when the calipers were removed.
If your system was let go to all air, it is not a matter of getting some bubbles removed but instead an issue of getting new fluid back into all areas of the system. If you look at all of the line junctions as well as the ABS, there needs to be lots of fluid movement with disturbance to get everything bled. If you can get a pressure bleeder to hold pressure and not leak around 10+ psi, the bubble removal goes much better.
Patience is much needed when doing this task...