Changing the Brake Fluid

[ORRadtech]

I've just noticed something.
The instructions for my pressure bleeder state that I should not exceed 28 psi.

On the pressure indicator the red zone starts at 32 psi.

However, here's what the service manual says:

Why do they recommend such a high pressure? 20 psi worked just fine for me.
Does this have to do with the valves in the ABS module? Do you need higher pressures to open them up?

A few thoughts.
28 psi seems oddly specific.
They say not to exceed 28 psi out of concern for the vehicle, not the tool.
Cheaper to buy a guage off the shelf than have a special one made.
Ford says 30-50 psi, if they tell their service people it can go to 50 psi it probably has.
Seems to me the factory service manual should be the authority, not a random tool manufacturer.
If 20 psi worked for you, great. 5 or 10 would have worked too.
30+ would have been faster
Pressure bleeding does not bleed the ABS, regardless of pressure. You will have to use a scan tool with that function to bleed ABS.
Tha ABS module doesn't hold enough fluid to affect your flush.

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[Vlad Soare]

I see. If it's just a matter of speed, then I'm good. I don't need more speed. It was fast enough as it was.
Thanks.

 

[luca1290]

I've always used the two person variant and pumped the pedal manually, but now I want to improve the process.

What's the difference between using this system, which feeds pressure from the reservoir vs using one that pulls it out from the caliper by using a vacuum?

I tried a time to use a (cheap) vacuum kit but it does not suck out a thing from the caliper, it just produces enough vacuum to drain the reservoir.

 

[Vlad Soare]

What's the difference between using this system, which feeds pressure from the reservoir vs using one that pulls it out from the caliper by using a vacuum?

Technically, none. This one is just easier and doesn't require a compressor.

 

[Vlad Soare]

I tried a time to use a (cheap) vacuum kit but it does not suck out a thing from the caliper, it just produces enough vacuum to drain the reservoir.

I didn't get to use mine for the actual brake bleeding, but it worked perfectly for removing the old fluid from the reservoir before connecting the pressure bleeder. These kits do get good reviews as far as I can tell, and many people seem to get along quite well with them, so I would expect them to work as advertised. Maybe you just needed more pressure? Or maybe the drain tube wasn't fit snuggly on the bleed nipple and was drawing air instead?

 

[BlueThunder16]

I've only done the two person method, but I want to make my life easier, so this time around I'm going to get the Motive kit. Just want to confirm which one fits 15-17 PP GTs. I've read and watched videos with guys using the 0109 kit on GT350s and it fit. But, it actually says it's for European vehicles. The 0118 kit however actually says it's for Ford Mustangs 05-2017. Can anyone confirm which one to buy?

Motive Kit 0109

https://www.amazon.com/gp/aw/d/B000Q6SL2W/ref=ox_sc_saved_image_1?smid=A2IS69AN9A0OWP&psc=1

Or

Motive Kit 0118

https://www.amazon.com/gp/aw/d/B00942X5EI/ref=ox_sc_saved_image_4?smid=A2IS69AN9A0sc=1

 

[GTP]

Why not support a forum sponsor?
https://www.opmustang.com/store/p21...-_2018_Ford_Mustang_-_C7_Corvette.html.html#/

 

[BlueThunder16]

Why not support a forum sponsor?
https://www.opmustang.com/store/p21...-_2018_Ford_Mustang_-_C7_Corvette.html.html#/

Sounds like a plan, thanks a lot! Seems to be the 0109 kit.

 

[S14Wolf]

If you get one of these bottles you'll never have a problem because the tubing will always be in the fluid unlike the pickle jar shown and when you pump you can see the new fluid transition color from old used to new from the MC. I actually prefer this over the motive pressure bleeder. https://www.amazon.com/Genesis-Pers...33&mcid=c7ca22f9287d3d718d6bcea0f5d04001&th=1

 

[GTP]

...
I actually prefer this over the motive pressure bleeder.

Don't you still need a MC pressure bleeder (or brake pedal helper) to use this?

 

[S14Wolf]

Don't you still need a MC pressure bleeder (or brake pedal helper) to use this?

No you put like maybe 20cc of brake fluid in the bottom of it to create the "seal" so no air can come back in. Where the fluid comes in, that tube goes all the way down to about 1/2" before the bottom of the canister. So you put the hose over the bleeder. Crack the bleeder. Then you can pump the brake pedal till you're happy. Close the bleeder and the line has no air in it. Makes bleeding a 1 person job if needed. Nothing overly complex.

 

[Buldawg76]

No you put like maybe 20cc of brake fluid in the bottom of it to create the "seal" so no air can come back in. Where the fluid comes in, that tube goes all the way down to about 1/2" before the bottom of the canister. So you put the hose over the bleeder. Crack the bleeder. Then you can pump the brake pedal till you're happy. Close the bleeder and the line has no air in it. Makes bleeding a 1 person job if needed. Nothing overly complex.

This is all dependent on how much you loosen the bleeder screw and how well the threads of the bleeder screw seal to the caliper. I have used a homemade bottle like this for years as a master tech and it's a 50/50 success rate of it not sucking air past the threads of the bleeder screw when doing by yourself. Motorcycles seem to be more susceptible to sucking air than cars but have had issues with both. More so on bike due to most using DOT 5 silicone fluid since it absorbs air not moisture so any air being sucked past threads of bleeder screw just absorbs into fluid making a good firm pedal impossible.

Just my .02 cents with from 50 years of experience.

Pressure bleeders are best for one person bleeding IMO.

BD

 

[GTP]

This is all dependent on how much you loosen the bleeder screw and how well the threads of the bleeder screw seal to the caliper. I have used a homemade bottle like this for years as a master tech and it's a 50/50 success rate of it not sucking air past the threads of the bleeder screw when doing by yourself. Motorcycles seem to be more susceptible to sucking air than cars but have had issues with both. More so on bike due to most using DOT 5 silicone fluid since it absorbs air not moisture so any air being sucked past threads of bleeder screw just absorbs into fluid making a good firm pedal impossible.

Just my .02 cents with from 50 years of experience.

Pressure bleeders are best for one person bleeding IMO.

BD

Agree with all the above. I loosen the bleed screw only 1/2 turn and the fluid comes out slowly. If you loosen any more than that, you think you are getting more bubbles out, but actually those are from air entering past the bleed screw threads.

 

[Buldawg76]

Agree with all the above. I loosen the bleed screw only 1/2 turn and the fluid comes out slowly. If you loosen any more than that, you think you are getting more bubbles out, but actually those are from air entering past the bleed screw threads.

Exactly and its different for every vehicle as to how much to loosen the screw to bleed but not allow air past threads.

BD

 

[murick]

This thread has been a very informative read. I would just like to comment on the recommended torque for the bleeder plugs.

I have methods that allow me not to have to obsess over fastener torque, but in the case of the bleed screws, DO use a 1/4" torque wrench to tighten the nipples to ~50 inch-pounds. You want a tight seal, but over tightening can damage the caliper seats which will then cause a leak.

There is a thread about this on M6G forum for GT350 here:
https://www.mustang6g.com/forums/threads/torque-values-for-caliper-bleed-screws.179044/

I was searching for the same info for Mach 1 and eventually found out that the torque depends on several factors (type of calipers, size of the bleeder plug). Here is an excerpt from original 2015 Mustang technical spec.

Another recommendation for Brembo calipers (from Brembo):
https://www.bremboparts.com/europe/...ctions-for-replacing-the-brake-caliper-280503

Bleeder plug	M6x1	M8x1,25	M10x1	M12x1
Tightening torque	5÷7 Nm	7÷10 Nm	17÷20 Nm	18÷22 Nm

I have yet to verify the exact size of the bleeder plug on Mach 1, but complementing both info, it seems 19 Nm (168 lb-in) looks like the right candidate.

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