How to bleed brakes with ABS?

[limulus]

Can anyone tell me the right way to bleed the brakes on a phI Renault 19 16V with Bendix ABS.
Search on the forums didn’t came up with the useful results. Haynes manual says that only entrusted Renault dealer can bleed the brakes with ABS.
And while googling on the net it’s seems that there is no single opinion on how to do it. Some suggest that one needs to press the brake pedal a few times with the ignition off, then depress pedal, turn ignition on. Others say that you should bleed them with ignition off. Yet another opinion is that you need to depressurize brake system before attempting to bleed the brakes, and can not pressure bleed the brakes (with easybleed kit or something) as it would damage the ABS unit.
So what is the correct way to bleed the brakes with ABS?

 

[danb]

using an ez bleed type-
Ignition and handbrake off. Pump brake pedal 10 times to empty accumilator.
Jack up rear, drop off wheels, **Carefully** lower the rear trailing arms onto axle stands taking care not to catch pipes or cables. This is to open the rear brake bias valve.
Fill resovoir to over max.
Screw on pressure cap.
Pressurise with about 20psi, no more.
Open bleed nipples one at a time with some pipe on, until no more bubbles come out.
Go round twice to be sure. Release pressure feed.
Make sure nipples are tight, Wheels on, stands out.
Top up fluid (make sure it doesnt run out while bleeding too) and replace cap, job done

 

[limulus]

So it is safe to pressure bleed brakes? I've read so many opinions on how (not) to do it that I’m really confused. And how would i do it using the "two-man" method? In what sequence should I bleed them? Like: Left Rear, Right Front, Right Rear, Left Front. Or can just go counter/ clockwise?

 

[danb]

well this is what we do on the 21Turbo and all 21Turbos have ABS.

The chairman of the club says this:

just read the renault braking section manual, it goes as follows, ignition off, empty accumulator by pressing the brake pedal 20 times then bleed front righthand wheel followed by front lefthand wheel, then the rear system, ignition off, empty accumulator by pressing the brake pedal 20 times then bleed the rear righthand wheel followed by the rear lefthand wheel.

 

[Chris H]

pressure bleeding rarely works only time I pressure bleed anything is with my tank and usually only for lorries and their clutches.

Gravity bleed them or 2 man it, easiest most reliable way.

As for the bias valve, you can just cable tie it closed so it won't stop the fluid

 

[limulus]

Gravity bleed them or 2 man it, easiest most reliable way.

so for the two-man job can I just follow Haynes instructions?:

Bleeding sequence
11 If the system has been only partially disconnected, and suitable precautions were taken to minimize fluid loss, it should be necessary only to bleed that part of the system (i.e. the primary or secondary circuit).
12 If the complete system is to be bled, then it should be done working in the following sequence:

(a) Left-hand rear brake.
(b) Right-hand front brake.
(c) Right-hand rear brake.
(d) Left-hand front brake.

Bleeding - basic (two-man) method

13 Collect a clean glass jar, a suitable length of plastic or rubber tubing which' is a tight fit over the bleed screw, and a ring spanner to fit the screw. The help of an assistant will also be required.
14 Remove the dust cap from the first screw in the sequence. Fit the spanner and tube to the screw, place the other end of the tube in the jar, and pour in sufficient fluid to cover the end of the tube.
15 Ensure that the reservoir fluid level is maintained at least above the "MIN" level line throughout the procedure.
16 Have the assistant fully depress the brake pedal several times to build up pressure, then maintain it on the final stroke.
17 While pedal pressure is maintained, unscrew the bleed screw (approximately one turn) and allow the compressed fluid and air to flow into the jar. The assistant should maintain pedal pressure, following it down to the floor if necessary, and should not release it until instructed to do so. When the flow stops, tighten the bleed screw again. Have the assistant release the pedal slowly.
18 Repeat the steps given in paragraphs 16 and 17 until the fluid emerging from the bleed screw is free from air bubbles. Remember to recheck the fluid level in the reservoir every five strokes or so. If the master cylinder has been drained and refilled, and air is being bled from the first screw in the sequence, allow approximately five seconds between strokes for the master cylinder passages to refill.
19 When no more air bubbles appear, tighten the bleed screw securely, remove the tube and spanner, and refit the dust cap. Do not overtighten the bleed screw.
20 Repeat the procedure on the remaining screws in the sequence, until all air is removed from the system, and the brake pedal feels firm.
21 Proceed to paragraph 30.
…
30 When bleeding is complete, and firm pedal feel is restored, wash off any spilt fluid, tighten the bleed screws securely, and refit their dust caps.
31 Check the hydraulic fluid level, and top-up if necessary.
32 Discard any hydraulic fluid that has been bled from the system; it will not be fit for reuse.
33 Check the feel of the brake pedal. If it feels at all spongy, air must still be present in the system, and further bleeding is required. Failure to bleed satisfactorily after several repetitions of the bleeding procedure may be due to worn master cylinder seals

Do i need to turn ignition on before bleeding each caliper. Because, as i understand, there will be no pressure left in the system after pumping brake pedal 10-20 times?

 

[Chris H]

you don't need pressure there is no pressure in the brake lines if there was the brakes would be on.

The system isn't as complicated as people make out and tbh the total failure is pretty rare as well.

Just do the standard 2 man method.

 

[hooverphonique]

I guess the good old 2-man method works in case of Bosch ABS as well then, even if Haynes says otherwise???

Need to switch the front hoses for MOT in 3 weeks time..
Would like to exchange fluid completely actually, since it's at least 5 years old by now...

 

[Neal R19]

Yeah normal 2-man or pressure bleed works fine for Bosch, it's just piggy backed onto the non-ABS braking system.

 

[Peter T]

2 man method. that be. undone bleed nipple pump it till no air bubble's. press down brake pedal to floor, while 2nd man. does up bleed nipple. release brake pedal. pump to test. / that the way I was shown when i was a kid. as i was the pumper. ???

 

[danb]

dont forget to give the calipers a tap with something to dislodge any air bubbles that could be stuck to the piston bore walls.

 

[rendan]

2 man method. that be. undone bleed nipple pump it till no air bubble's. press down brake pedal to floor, while 2nd man. does up bleed nipple. release brake pedal. pump to test. / that the way I was shown when i was a kid. as i was the pumper. ???

So remember guy's pete's a pumper.

 

[hooverphonique]

does the alb valve open or close with regards to rear braking when the rear is raised?
i guess it's easier to bleed rear when it's open?

 

[Chris H]

the valve closes which is why I have described what to do about a million times in a million posts.

 

[hooverphonique]

thanks, chris.. I tried searching for alb and regulator, but nothing related came up..