Caliper swap - bleed before and after or just after?

[mikes2017gt]

I'm in the process of swapping my 4-piston stock calipers for the 6-piston Brembos. The brake fluid in the system is 82K miles/8 years old. Yeah, I know. Neglect.

I am planning to flush the entire system after the new calipers are installed. But, being that the lines are currently full of nasty, old fluid, I was thinking rather than pump all that bad fluid through the new calipers in the process of bleeding them, I just flush the system with the old calipers on there. Once the fluid runs clean I stop.

Put on the new calipers and then bleed all the air out of the system. My thought is to avoid filling the new calipers with nasty old fluid and debris.

On the surface this seems like a good plan, but I'm sure there is something I'm not considering. Thoughts? Thanks.

Powerstop 15" rotor hanging out, waiting for a caliper.

Brembos loaded with Powerstop Z26 pads and StopFlex braided lines.

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[skinnyb]

Sounds like a solid plan to me. Just do the rears first.. Start at right rear, then left rear, right front, left front... That is the order I always use, and recommended.. I personally use the Motive Power bleeder for fluid changes, makes it a one person job.

 

[DougS550]

I'm in the process of swapping my 4-piston stock calipers for the 6-piston Brembos. The brake fluid in the system is 82K miles/8 years old. Yeah, I know. Neglect.

I am planning to flush the entire system after the new calipers are installed. But, being that the lines are currently full of nasty, old fluid, I was thinking rather than pump all that bad fluid through the new calipers in the process of bleeding them, I just flush the system with the old calipers on there. Once the fluid runs clean I stop.

Put on the new calipers and then bleed all the air out of the system. My thought is to avoid filling the new calipers with nasty old fluid and debris.

On the surface this seems like a good plan, but I'm sure there is something I'm not considering. Thoughts? Thanks.

Sounds like a solid plan to me. Just do the rears first.. Start at right rear, then left rear, right front, left front... That is the order I always use, and recommended.. I personally use the Motive Power bleeder for fluid changes, makes it a one person job.

 

[skinnyb]

Yep thats the one I use works like a charm... And I use DOT4 fluid, I do use an aftermarket brand though, nothing too fancy but it works..

https://www.amazon.com/dp/B003479F66?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

 

[DougS550]

Yep thats the one I use works like a charm... And I use DOT4 fluid, I do use an aftermarket brand though, nothing too fancy but it works..

https://www.amazon.com/dp/B003479F66?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

As long as it is Dot 4 LV the spec is met. I think I used over 4 liters when I done my purge after installing switched to steel braided brake lines.

 

[mikes2017gt]

Thanks, guys. Glad I'm on the right track.

4 liters of fluid for a full flush? I think I need to order more brake fluid before I start. I only bought 4 bottles and already used half a bottle topping off the reservoir after sucking out as much fluid as I could with a syringe.

BTW, I did not know that the reservoir fill opening is NOT the same diameter as the cap. About 1" down from top of the opening, it necks down to like a 1/2" opening. That's kind of dumb. Guess I would've known that already if I'd changed my brake fluid about 40K miles ago.

You can see the Motorcraft DOT4 fluid in the background in the pics I attached to the original post. I also have the Motive power bleeder and the correct reservoir cap.

 

[DougS550]

Thanks, guys. Glad I'm on the right track.

4 liters of fluid for a full flush? I think I need to order more brake fluid before I start. I only bought 4 bottles and already used half a bottle topping off the reservoir after sucking out as much fluid as I could with a syringe.

BTW, I did not know that the reservoir fill opening is NOT the same diameter as the cap. About 1" down from top of the opening, it necks down to like a 1/2" opening. That's kind of dumb. Guess I would've known that already if I'd changed my brake fluid about 40K miles ago.

You can see the Motorcraft DOT4 fluid in the background in the pics I attached to the original post. I also have the Motive power bleeder and the correct reservoir cap.

For me, the power bleeder uses more fluid plus I was chasing air that got into my system due to not capping my lines when I removed calipers to paint. Ouch!!!

 

[mikes2017gt]

The last thing I want to do is run the power bleeder dry and put air in the system. Call it "the cost of doing business" for the fluid I won't use and will wind up throwing away. Still cheaper than having it done at the stealership.

I've actually never used the power bleeder before. It's been on the shelf for a long time...like the rotors/calipers and pads I"m putting on. Plenty of experience bleeding brakes the old fashioned way...and it sucks and I'm not doing it that way again.

 

[DougS550]

The last thing I want to do is run the power bleeder dry and put air in the system. Call it "the cost of doing business" for the fluid I won't use and will wind up throwing away. Still cheaper than having it done at the stealership.

I've actually never used the power bleeder before. It's been on the shelf for a long time...like the rotors/calipers and pads I"m putting on. Plenty of experience bleeding brakes the old fashioned way...and it sucks and I'm not doing it that way again.

Definitely don't want to run the tank dry. It pushes it through the system fast, so I periodically stopped bleeding to check tank level just to make sure.

 

[Garfy]

Sounds like a solid plan to me. Just do the rears first.. Start at right rear, then left rear, right front, left front... That is the order I always use, and recommended.. I personally use the Motive Power bleeder for fluid changes, makes it a one person job.

That's correct for a LHD model per the service manual, which I presume all of us have if we're in the U.S. RHD models would be LR, RR, LF and RF.

 

[skinnyb]

That's correct for a LHD model per the service manual, which I presume all of us have if we're in the U.S. RHD models would be LR, RR, LF and RF.

True. I always forget about those right hand drive models . Basically farthest to closest to the master cylinder.

 

[skinnyb]

Thanks, guys. Glad I'm on the right track.

4 liters of fluid for a full flush? I think I need to order more brake fluid before I start. I only bought 4 bottles and already used half a bottle topping off the reservoir after sucking out as much fluid as I could with a syringe.

BTW, I did not know that the reservoir fill opening is NOT the same diameter as the cap. About 1" down from top of the opening, it necks down to like a 1/2" opening. That's kind of dumb. Guess I would've known that already if I'd changed my brake fluid about 40K miles ago.

You can see the Motorcraft DOT4 fluid in the background in the pics I attached to the original post. I also have the Motive power bleeder and the correct reservoir cap.

I used 2 liters. Sucked out the reservoir and filled. Then put the rest of that bottle and the other new one in the bleeder. Still had about 4 oz left in bleeder tank. I used a 4 oz collection jar. Collected it 3 times on the right rear, twice on the left rear since the line going to the back was then clear. Then each screw on the caliper once up front (2 bleeders per caliper). Inner one first then outer. Ended with the outer on the driver side front.

 

[GTP]

All good advice so far.

Many of us never fill the Motive bottle, but just use it for pressure. Uses less fluid and no need to clean out the bottle after. But you have to keep track of the reservoir level even more diligently. Shine a flashlight from above and you can see the level.

If you wanted, you can even blow compressed air through your lines after gravity bleeding out all the old fluid. Be sure to put a shop rag around the end of each line so as not to blow brake fluid mist onto your paint.

I would then connect everything and gravity bleed fluid into the lines. Open the farthest caliper first, then close after seeing fluid, then onto to the next farthest, and so on. Then proceed with the typical air purging process with the Motive setup.

 

[mikes2017gt]

I'm looking forward to trying the Motive power bleeder. I'm going to put the fluid into the bleeder because my brake reservoir is kind of discolored and it's difficult to see the fluid level.

Was hoping to buy more Motorcraft DOT4 locally, so I could maybe work on the brakes tonight or tomorrow. Four different parts stores near me and not one carries Motorcraft fluid. Ordered it on Amazon and it's supposed to arrive on Wed. But Amazon's delivery times to me have slipped quite a bit since the start of the year. Don't want to risk running out of fluid mid-bleed.

I know the Ford dealer near me has it....for $28+ tax per 16oz bottle. Yeah, don't want it that badly.

 

[WItoTX]

I'm looking forward to trying the Motive power bleeder. I'm going to put the fluid into the bleeder because my brake reservoir is kind of discolored and it's difficult to see the fluid level.

Was hoping to buy more Motorcraft DOT4 locally, so I could maybe work on the brakes tonight or tomorrow. Four different parts stores near me and not one carries Motorcraft fluid. Ordered it on Amazon and it's supposed to arrive on Wed. But Amazon's delivery times to me have slipped quite a bit since the start of the year. Don't want to risk running out of fluid mid-bleed.

I know the Ford dealer near me has it....for $28+ tax per 16oz bottle. Yeah, don't want it that badly.

I only ever need a full liter to swap all the fluid. I usually buy two just in case. Since you are filling up the pistons themselves, I would definitely start with at least 3 liters.

Keep in mind, if the fluid drains out while swapping lines and calipers, you need to bleed the ABS block too (Forscan has a tool for this). And along the braided line swap, get yourself a nut that threads onto the factory brake line. See this thread for details (https://www.mustang6g.com/forums/threads/please-help-rear-brakes.186602/) A lot of guys (Myself included) had to deal with the factory over tightening the rubber line to the rigid line connection, which distorts the threads. Getting the proper size nut allows you to run that on and off a few times and fix that distortion.

Finally, I never put fluid in the Motive Bottle, because I don't want to drain it if there is left over fluid, and I am too paranoid that if I leave the fluid in the bottle for a year or more, it will go bad. I usually just fill the reservoir to the top, then put a light behind it so I can see the fluid level as it is pumped through the system. The Motive bottle basically just put's pressure on the system for me.

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