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Brake fluid bleeding
- Thread starter inquirer
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Nope. You need to bleed the rears too if you want to change the fluid out the back.
At the repair shop they reassured me that by sucking out the fluid from the front bleeder screws it is sufficient also for the rear hoses to get empty, which didn't make sense to me...
If I'm going to redo it, should I just do the rear brakes that were left unopened or do also the fronts?
If I'm going to redo it, should I just do the rear brakes that were left unopened or do also the fronts?
Originally Posted By: inquirer
At the repair shop they reassured me that by sucking out the fluid from the front bleeder screws it is sufficient also for the rear hoses to get empty, which didn't make sense to me...
If I'm going to redo it, should I just do the rear brakes that were left unopened or do also the fronts?
You need to start looking for a new shop if they're feeding you such hocus pocus. There is a reason why people bleed all 4 corners instead of just 2. The only time I can see it working is if they open the rear bleeders and hook them up to a brake fluid reservoir while sucking out all the old fluid through the fronts. I don't think they do that.
You may get 75% if the old fluid by bleeding from the furthest points (rears) but you will still miss the sections between the master cylinder (or proportioning valve) to the front calipers.
My suggestion, do all for corners. You'll sleep better too.
At the repair shop they reassured me that by sucking out the fluid from the front bleeder screws it is sufficient also for the rear hoses to get empty, which didn't make sense to me...
If I'm going to redo it, should I just do the rear brakes that were left unopened or do also the fronts?
You need to start looking for a new shop if they're feeding you such hocus pocus. There is a reason why people bleed all 4 corners instead of just 2. The only time I can see it working is if they open the rear bleeders and hook them up to a brake fluid reservoir while sucking out all the old fluid through the fronts. I don't think they do that.
You may get 75% if the old fluid by bleeding from the furthest points (rears) but you will still miss the sections between the master cylinder (or proportioning valve) to the front calipers.
My suggestion, do all for corners. You'll sleep better too.
All 4 brakes need to be bleed. This also means you are opening the bleeder screw more often so its less likely to get corroded in place.
Note if your only doing a flush and with PB Blaster and a 6 point socket you cannot get a bleeder open to bleed it, then I would skip that wheel.
Note if your only doing a flush and with PB Blaster and a 6 point socket you cannot get a bleeder open to bleed it, then I would skip that wheel.
The rule of thumb used to be "bleed all corners, starting with the one closest to the brake master cylinder and working progressively further away."
ABS/traction/stability systems complicate things because you really need a scan-tool that will run the pumps to clear any old fluid and/or air out of that part of the system. If you never let air in except at the wheels, you can usually get away without doing that, and the fluid will exchange over time as the system does its start-up pump test or actually operates. Regular fluid changes/partial bleedings help with that as well.
ABS/traction/stability systems complicate things because you really need a scan-tool that will run the pumps to clear any old fluid and/or air out of that part of the system. If you never let air in except at the wheels, you can usually get away without doing that, and the fluid will exchange over time as the system does its start-up pump test or actually operates. Regular fluid changes/partial bleedings help with that as well.
Originally Posted By: inquirer
At the repair shop they reassured me that by sucking out the fluid from the front bleeder screws it is sufficient also for the rear hoses to get empty, which didn't make sense to me...
If I'm going to redo it, should I just do the rear brakes that were left unopened or do also the fronts?
If my shop told me that, I would go elsewhere.
At the repair shop they reassured me that by sucking out the fluid from the front bleeder screws it is sufficient also for the rear hoses to get empty, which didn't make sense to me...
If I'm going to redo it, should I just do the rear brakes that were left unopened or do also the fronts?
If my shop told me that, I would go elsewhere.
Originally Posted By: 440Magnum
The rule of thumb used to be "bleed all corners, starting with the one closest to the brake master cylinder and working progressively further away."
ABS/traction/stability systems complicate things because you really need a scan-tool that will run the pumps to clear any old fluid and/or air out of that part of the system. If you never let air in except at the wheels, you can usually get away without doing that, and the fluid will exchange over time as the system does its start-up pump test or actually operates. Regular fluid changes/partial bleedings help with that as well.
I have always started with the RR,LR, RF then LF. Farthest from master cylinder to the closest.
The rule of thumb used to be "bleed all corners, starting with the one closest to the brake master cylinder and working progressively further away."
ABS/traction/stability systems complicate things because you really need a scan-tool that will run the pumps to clear any old fluid and/or air out of that part of the system. If you never let air in except at the wheels, you can usually get away without doing that, and the fluid will exchange over time as the system does its start-up pump test or actually operates. Regular fluid changes/partial bleedings help with that as well.
I have always started with the RR,LR, RF then LF. Farthest from master cylinder to the closest.
Originally Posted By: Lubener
Originally Posted By: 440Magnum
The rule of thumb used to be "bleed all corners, starting with the one closest to the brake master cylinder and working progressively further away."
ABS/traction/stability systems complicate things because you really need a scan-tool that will run the pumps to clear any old fluid and/or air out of that part of the system. If you never let air in except at the wheels, you can usually get away without doing that, and the fluid will exchange over time as the system does its start-up pump test or actually operates. Regular fluid changes/partial bleedings help with that as well.
I have always started with the RR,LR, RF then LF. Farthest from master cylinder to the closest.
That is how I have always done it. You must be old, too!
Originally Posted By: 440Magnum
The rule of thumb used to be "bleed all corners, starting with the one closest to the brake master cylinder and working progressively further away."
ABS/traction/stability systems complicate things because you really need a scan-tool that will run the pumps to clear any old fluid and/or air out of that part of the system. If you never let air in except at the wheels, you can usually get away without doing that, and the fluid will exchange over time as the system does its start-up pump test or actually operates. Regular fluid changes/partial bleedings help with that as well.
I have always started with the RR,LR, RF then LF. Farthest from master cylinder to the closest.
That is how I have always done it. You must be old, too!
Originally Posted By: 4wheeldog
Originally Posted By: Lubener
I have always started with the RR,LR, RF then LF. Farthest from master cylinder to the closest.
That is how I have always done it. You must be old, too!
My only problem with that is the chance that some dirt or air left in a branch line going to a closer wheel might get into the branch line going to the farthest wheel after you're done bleeding the farthest wheel and lift the pedal that last time. So I go closest to farthest so that the clean fluid works its way steadily outward from the MC.
In fairness, its way down in the weeds compared to just making sure you adequately bleed all 4... in ANY order.
Originally Posted By: Lubener
I have always started with the RR,LR, RF then LF. Farthest from master cylinder to the closest.
That is how I have always done it. You must be old, too!
My only problem with that is the chance that some dirt or air left in a branch line going to a closer wheel might get into the branch line going to the farthest wheel after you're done bleeding the farthest wheel and lift the pedal that last time. So I go closest to farthest so that the clean fluid works its way steadily outward from the MC.
In fairness, its way down in the weeds compared to just making sure you adequately bleed all 4... in ANY order.
Originally Posted By: Sawdusted
The only time I can see it working is if they open the rear bleeders and hook them up to a brake fluid reservoir while sucking out all the old fluid through the fronts. I don't think they do that.
Never thought of doing that. It'd be effectively a back-flush for the rear.
I was told in a recent thread that the back-flush is the mark of the automotive anti-[censored], so of course its what I do to refill my system.
This variant would limit pressure/backflow into the master-cylinder until you flushed the rest of the system.
Hmm...Might try it. I only have one rear bleed nipple so it sort of fits.
(Oh, and yes, they are talking bollocks. SOP for mechanics here, though some of it gets lost in translation)
The only time I can see it working is if they open the rear bleeders and hook them up to a brake fluid reservoir while sucking out all the old fluid through the fronts. I don't think they do that.
Never thought of doing that. It'd be effectively a back-flush for the rear.
I was told in a recent thread that the back-flush is the mark of the automotive anti-[censored], so of course its what I do to refill my system.
This variant would limit pressure/backflow into the master-cylinder until you flushed the rest of the system.
Hmm...Might try it. I only have one rear bleed nipple so it sort of fits.
(Oh, and yes, they are talking bollocks. SOP for mechanics here, though some of it gets lost in translation)
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