What order do I bleed and replace brake hoses?

[jonesg]

i use a wooden stick to hold brake pedal pressure as i open and close the bleeder , when it stops spitting its good.

[BlackBart]

I assume you meant brake hoses. Don't I need to bleed immediately after replacing to get the hose filled with fluid?

Air is only at the end of the line if the system is not soft. Don't want to bleed all at once and discover after the 4th it's still soft. Have to redo all again not knowing which one is the culprit.

He’s replacing hoses, so the system is open.

02V70 - you’re essentially flushing the system with new fluid and then bleeding air bubbles out after all lines are filled.

I didn’t know about the front wheels first bleed order - is this because of ABS piping?

[MoVolvos]

I assume you meant brake hoses. Don't I need to bleed immediately after replacing to get the hose filled with fluid?

Air is only at the end of the line if the system is not soft. Don't want to bleed all at once and discover after the 4th it's still soft. Have to redo all again not knowing which one is the culprit.

He’s replacing hoses, so the system is open.

02V70 - you’re essentially flushing the system with new fluid and then bleeding air bubbles out after all lines are filled.

I didn’t know about the front wheels first bleed order - is this because of ABS piping?

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I replaced all the 03 S80 T6 hoses with a set of FCP stainless a few years back. The fluid just gravity flow so no air except at the end. I flushed till the fluid was clear and pedal firm then continued.

If I replaced all the lines and after bleeding the last found it was soft, I wouldn’t know which line needs more work. This is why you need to establish a baseline.

If you start with a spongy pedal you would bleed all four. Assuming after bleeding the first line and the system is soft, you either bleed more or go to the next if you don’t see any bubbles. Hopefully in between or by the last line the system is purge and pedal firm.

I did the short line first or reverse bleeding not too long ago. Didn’t want to mention it as it is not what everyone is use to. Can see why it wouldn’t make a difference as each individual brake line starts close to the reservoir.
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[02V70]

When you say soft, that means there is air in the system, right? When pressing the pedal to see if it is spongy, I do not need to start the engine, correct?

[MoVolvos]

When you say soft, that means there is air in the system, right? When pressing the pedal to see if it is spongy, I do not need to start the engine, correct?

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Yes, start the engine to determine where your system is at. If it's spongy you could go ahead and bleed the system till it's firm. This way you know which line had air. Once you start you might as well bleed all the other lines so there is fresh fluid in the entire system. Make sure to bleed until new fluid is coming out regardless whether if the air comes out right away. After you replace each brake line you only have to bleed the new (last) section of air so pretty quick as the system already has new fluid through out.

If the system is firm after testing you can go ahead and replace the line but be sure to bleed till new fluid comes out. You are not only purging air but flushing that entire section of dirty fluid. Only when the brake is firm with new fluid coming out do you proceed to the next brake line replacement.

Doing this ensures you know your work is done well before preceding.
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[abscate]

Each time I have a caliper open I replace any older bleed valve with a FreeCP one, the push 257 ml of brake fluid through to get fresh stuff in. 4x 250 ml is one liter, which also goes back to FCP

[vtl]

For the spongy brake pedal you need to actuate ABS. Chances are the air bubble is not in ABS, but frankly I don't remember I ever heard of air in P2 brake system that was not in ABS.

You need DiCE or Mongoose JLR cable (that is: Jaguar Land Rover - it has 2 CAN buses as well), and VIDA, of course.

[volvolugnut]

Each time I have a caliper open I replace any older bleed valve with a FreeCP one, the push 257 ml of brake fluid through to get fresh stuff in. 4x 250 ml is one liter, which also goes back to FCP

When FCP stops return for credit for you, we will know the limit of their generosity.


volvolugnut

[02V70]

Why would there be air in my abs system? I am flushing the brakes because I am replacing the brake hoses and might as well flush the old brake fluid at the same time. The pedal was never spongy. Removing the brake hoses and bleeding the brakes should not introduce air into the abs system, right?

[MoVolvos]

Why would there be air in my abs system? I am flushing the brakes because I am replacing the brake hoses and might as well flush the old brake fluid at the same time. The pedal was never spongy. Removing the brake hoses and bleeding the brakes should not introduce air into the abs system, right?

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Yes, your baseline is system without air so you're good to go with the line replacement. Just bleed entire line till you see clean fluid before continuing to the next.
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