I recently replaced my master cylinder on my 96 960 wagon and I used a power bleeder to bleed the lines twice but I still have a soft pedal. I bench bled the mc but I did lose fluid while trying to connect the brake lines. The brakes appear to be fine and I just had the rears done a few months ago. Coulple of questions.
1. What is the correct order for bleeding an ABS system? The first time I went RR LR RF LF but still had a soft pedal. Did a liitle research and found the ABS should be done completely opposite, LF RF LR RR, did that and I did get air out the second time in the RR line.
2. Is it common to power bleed a system numerous times or should I be looking at another part?
3. My rear calipers have two bleed valves an upper and a lower, logic would have me bleed the lower then the upper, is that correct?
4. I also read that with ABS you have to clamp the brake line near the caliper and open the bleeder and push the piston back into the caliper. I didn't do this yet, could this a source for the air? Also, when doing this procedure do all four calipers have to be serviced this way or just the rears?
5. There are two bleeders on the mc, do those need to be bled also and if so in what order? I bled them on my two jobs and did them last.

Thanks for your help!

With a Motive Products Power Bleeder you can pressurise the system to 20-30 psi.

1) Bleed RR, LR, RF then LF on these cars. No special proceedure for the ABS on these Volvo's.

2) Once should do it.

3) The upper nipple on the rear calipers is the correct one to bleed.

4) - Sounds like your changing the pads?
- You don't have to do this but it's good adivce when retracting the pistons
during pad removal.
- It shouldn't be the source of your air.
- It's a good precaution on all calipers.

5) If you bench bled the master cylinder and got all the air our before installing, then you shouldn't have to bleed the MC again, only the calipers.

Following this proceedue you should not have a soft pedal.

DEWFPO
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1998 S90 070,050 and 1995 964 153,010

I have the Motive Power Bleeder. I was reading about brakes in FAQ section and they said you may and should pump the brakes to get the rear brakes rock hard. With the power bleeder attached and under pressure, would it be OK to pump the brakes? I'm going to bleed them again and try pumping the brakes while the bleeder is open(with tube attached and immersed in a bottle of fluid). Hopefully that should stiffen up the pedal.

"With the power bleeder attached and under pressure, would it be OK to pump the brakes?"

I've never done it that way so I can't say. But I don't see how it could cause a problem.

DEWFPO
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1998 S90 068,300 and 1995 964 152,300

I finally found a few hours to tackle this problem again over the weekend. I power bled the brakes and I also pumped the brakes,while the car was running. I did get air out of the left rear only, each time I bleed the sysytem. I thought I had it fixed. I pumped and bled, pumped and bled until there was no more air coming out. The pedal was rock hard. I put the wheel back on and lowered the car and when I started it the pedal was soft again. I don't see any fluid leaking and the mc seems to be at a constant level.
Is it possible the mc is bad. I bought it at Grotons($135)
Is it possible for a caliper to be bad without leaking?
The only air i get out of the system is always the left rear.

I've bled this thing 5 times and I'm still in the same place as i was before i changed the mc. The guys at Pep Boys are considering stocking brake fluid in 55 gallon drums for me!!!!!!

Thanks for your time and insight on this.

lightbulbguy,

I am no brake expert but somehow air is getting back into the system as you've discovered. When you pressure bleed the LR does the air come out immdiately or after you've pushed some fluid thru the system? I am trying to determine if the air is at the caliper or at the master cylinder end of the system to try to nail down where it's coming from.

All bleeder screws are tight? especially those on the MC?

DEWFPO
--
1998 S90 068,300 and 1995 964 152,300

Good point, the air seems to take a while to start appearing. There are two bleeders on the mc, is the one closer to the firewall for the rear brakes and the front one for the front brakes? I had to reuse the old bleeders from the other mc. I did notice the rear bleeder was leaking slightly after i initally changed the mc. I had to tighten it pretty good to stop the flow. When I bled the system last I did check around the mc for any wet spots and didn't find any. Is it possible for a bleeder valve to let air in without losing fluid especially on the mc? Do you think I should replace the bleeder on the mc? I,m going to crawl under ther this weekend and check the entire length of that brake line for any leaks. Can brake lines be spliced with another section or do you have to replace the entire section?

Thanks
Neil

Hi Neil,

"There are two bleeders on the mc, is the one closer to the firewall for the rear brakes and the front one for the front brakes?"

I don't know for sure. Used to be they were just the opposite.

"I had to reuse the old bleeders from the other mc. I did notice the rear bleeder was leaking slightly after i initally changed the mc."

I would replace both bleeders. If fluid can leak out, air can leak in.

"Is it possible for a bleeder valve to let air in without losing fluid especially on the mc?"

Good question, I don't know. I would replace any bleeder is question.

"Can brake lines be spliced with another section or do you have to replace the entire section?"

They can be spliced, you need a DOUBLE Flare Tool to do this. The lines are steel and you need a good quality tool to do this right and have no leaks. These lines are put under a tremendous amout of pressure when you hit the brakes hard. The line is flared once, then bent back over itself with the tool. Check the price of the tool, it might be cheaper and easier to replace an entire section of line if you need to.

DEWFPO



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1998 S90 070,350 and 1995 964 153,650