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      09-19-2021, 07:54 AM   #1
PackPride85
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Brake Bleeding Question

Going to be bleeding the brakes soon myself for first HPDE event. Picked up the Motive pressure bleeder and RBF600. There seem to be slightly differing methods with filling the reservoirs. Most people remove the car's reservoir fluid and fill the motive tank. Some fill the car reservoir and motive tank. Some just fill the car reservoir and leave the motive tank empty.

Is there any difference between these methods?
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      09-19-2021, 08:17 AM   #2
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Removing the fluid from the car's reservoir reduces the amount you have to remove by flushing it through the system if you're flushing all fluid out. If your goal is to not flush all of the old fluid out but to flush just the stuff near the caliper, you don't have to suck the old fluid out of the car's reservoir. So sucking it out is just for a complete flush (or if you have junk in there).

If you don't fill the Motive with fluid, then your goal is likely to just flush the fluid near the caliper. In this case the Motive device is used to help to push the fluid through. Be careful though, the last thing that you'll likely want to happen is to run out of fluid in the reservoir and suck air causing the need to flush it all over again to get the air out. If you're doing it this way, then keep a close eye on the amount in the car's reservoir after each nipple or caliper (the fronts have two nipples each) so the reservoir doesn't suck air.
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      09-19-2021, 08:28 AM   #3
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Quote:
Originally Posted by M2guru View Post
Removing the fluid from the car's reservoir reduces the amount you have to remove by flushing it through the system if you're flushing all fluid out. If your goal is to not flush all of the old fluid out but to flush just the stuff near the caliper, you don't have to suck the old fluid out of the car's reservoir. So sucking it out is just for a complete flush (or if you have junk in there).

If you don't fill the Motive with fluid, then your goal is likely to just flush the fluid near the caliper. In this case the Motive device is used to help to push the fluid through. Be careful though, the last thing that you'll likely want to happen is to run out of fluid in the reservoir and suck air causing the need to flush it all over again to get the air out. If you're doing it this way, then keep a close eye on the amount in the car's reservoir after each nipple or caliper (the fronts have two nipples each) so the reservoir doesn't suck air.
I'm doing a complete flush to replace the oem fluid. Was going to remove oem fluid from reservoir and fill motive tank. Saw some people also refilling the oem reservoir in addition to motive tank for flush. Wasn't sure if filling both before bleeding was necessary.

I've also seen a few people pump them brake pedal a few times while bleeding each caliper.
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      09-19-2021, 10:22 AM   #4
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The main benefit to not filling the Motive is that it stays clean.
If you put fluid in the Motive it needs to be flushed & cleaned out afterwards.

Definitely suck most of the fluid out of the reservoir with a turkey baster.
The fresh fluid gets through the system without mixing as much with the old.

I keep the Motive dry; suck out the old; & fill the reservoir.
- do one caliper then remove Motive & top up the reservoir. (do NOT let it go dry)
- repeat for each caliper.

No need to use the brake pedal if your brakes are working OK.
If you think you have air (soft pedal), then the old school method with brake pedal helps.

I also tap the caliper with a rubber mallet to dislodge any trapped air bubbles.
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      09-20-2021, 02:08 AM   #5
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If you have 2NH, don't forget to bleed from 2 nipples, as God intended.
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      09-20-2021, 03:23 AM   #6
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Quote:
Originally Posted by PackPride85 View Post
Quote:
Originally Posted by M2guru View Post
Removing the fluid from the car's reservoir reduces the amount you have to remove by flushing it through the system if you're flushing all fluid out. If your goal is to not flush all of the old fluid out but to flush just the stuff near the caliper, you don't have to suck the old fluid out of the car's reservoir. So sucking it out is just for a complete flush (or if you have junk in there).

If you don't fill the Motive with fluid, then your goal is likely to just flush the fluid near the caliper. In this case the Motive device is used to help to push the fluid through. Be careful though, the last thing that you'll likely want to happen is to run out of fluid in the reservoir and suck air causing the need to flush it all over again to get the air out. If you're doing it this way, then keep a close eye on the amount in the car's reservoir after each nipple or caliper (the fronts have two nipples each) so the reservoir doesn't suck air.
I'm doing a complete flush to replace the oem fluid. Was going to remove oem fluid from reservoir and fill motive tank. Saw some people also refilling the oem reservoir in addition to motive tank for flush. Wasn't sure if filling both before bleeding was necessary.

I've also seen a few people pump them brake pedal a few times while bleeding each caliper.
You don't need to refill the tank before fitting the pressure bleeder.

The first thing that will happen when you apply pressure to the system, is fluid will transfer from the pressure bleeder to the reservoir filling it anyways.

That's the magic of a pressure bleeder it auto fills the reservoir so no air can get in the system (unless the bleeder runs out of juice and the level in the MC drops too low).

Having said that filling the MC first means you might save yourself from having to refill the pressure bleeder half way through.

Have a syringe handy as the pressure bleeder will fill the MC reservoir to the brim and you need to bring this back down to bellow max level. Typically I suck out as much as I can with the screen in place. This leaves you a little under max which is good if you track as at max it's possible the fluid will expand and leak past the cap. I have seen it happen on my mates S55 cars.
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      10-06-2021, 06:58 PM   #7
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Quote:
Originally Posted by Megator View Post
Quote:
Originally Posted by PackPride85 View Post
Quote:
Originally Posted by M2guru View Post
Removing the fluid from the car's reservoir reduces the amount you have to remove by flushing it through the system if you're flushing all fluid out. If your goal is to not flush all of the old fluid out but to flush just the stuff near the caliper, you don't have to suck the old fluid out of the car's reservoir. So sucking it out is just for a complete flush (or if you have junk in there).

If you don't fill the Motive with fluid, then your goal is likely to just flush the fluid near the caliper. In this case the Motive device is used to help to push the fluid through. Be careful though, the last thing that you'll likely want to happen is to run out of fluid in the reservoir and suck air causing the need to flush it all over again to get the air out. If you're doing it this way, then keep a close eye on the amount in the car's reservoir after each nipple or caliper (the fronts have two nipples each) so the reservoir doesn't suck air.
I'm doing a complete flush to replace the oem fluid. Was going to remove oem fluid from reservoir and fill motive tank. Saw some people also refilling the oem reservoir in addition to motive tank for flush. Wasn't sure if filling both before bleeding was necessary.

I've also seen a few people pump them brake pedal a few times while bleeding each caliper.
You don't need to refill the tank before fitting the pressure bleeder.

The first thing that will happen when you apply pressure to the system, is fluid will transfer from the pressure bleeder to the reservoir filling it anyways.

That's the magic of a pressure bleeder it auto fills the reservoir so no air can get in the system (unless the bleeder runs out of juice and the level in the MC drops too low).

Having said that filling the MC first means you might save yourself from having to refill the pressure bleeder half way through.

Have a syringe handy as the pressure bleeder will fill the MC reservoir to the brim and you need to bring this back down to bellow max level. Typically I suck out as much as I can with the screen in place. This leaves you a little under max which is good if you track as at max it's possible the fluid will expand and leak past the cap. I have seen it happen on my mates S55 cars.
Did the brake fluid this morning. Went fairly smooth although there was a ton of air that came out of the rear passenger side. I let that one bleed for a while until the bubbles stopped. The rest had little to no air. I did end up using 3 full bottles of rbf 600, mostly because it was hard to tell when the rbf made it to the caliper. First time so better to be sure.

Also noticed my front driver side tire has the cords showing when I took the wheel off. Glad I caught that before hpde in 2 weeks. Got some 255/275 ps4s on order.

I have hawk dtc-60s pads I'm going to swap in a few days before driving to the track.
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      10-09-2021, 08:20 AM   #8
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Enjoy! I like the RBF600 great fluid for a great price. Might try the Endless one next as it is meant to give a great pedal feel but its 5 times more expensive!
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