Ever since I got my 1999 v70 T5M a month back, the brake pedal has been strange. It felt kinda like air in the lines--when you'd push it would go down quite a ways, but if pumped quickly a few times it would really firm up. Braking was always strong, just sometimes the pedal went a ways before working.

I went to bleed the brakes a few weeks ago and (naturally) the front bleed screws broke right off. I bled the rears and it seemed like things were a bit better (placebo probably...).

Since one of the parking brakes was not working, the pads were only 1/3 left on the rear, and the rotors didn't look to good back there, I just replaced all four calipers and the entire rear brake assembly, including parking brakes, rotors, and pads. I also did the front brake hoses.

I bled the brakes three times with my pressure bleeder, just to be safe. When I went to firm up the pedal with the new calipers on, the pedal traveled a long ways a few times until the caliper cylinders pushed the pads against the rotors. I then bled once more (I'm anal).

Now, with the car on, the pedal goes right to the floor and there's no braking at all unless I pump the pedal a bunch. I even bled one more time to make sure there's no air in the system. I definitely never let the master cylinder run dry.

Basically, I'm left thinking it MUST be the master cylinder with an internal failure. There are no leaks that I can find anywhere on the car, but there's no braking. Does this sound likely/probable? I don't want to buy a new MC and install it only to end up at the same place where I am already. Could anything with the abs module cause this?

Thanks!

Nate
--
1997 850, 1979 242GT, 1990 740GL

Because you got new calipers, make sure the pad spring is installed properly. A bad spring placement will result in very weak braking because the pad travels too far to get a solid grip.
--
My name is Klaus and I am a Volvoholic.

Hmm...interesting. I just checked the springs: one was just fine but the other was not on correctly. An hour of messing with it resulted in absolutely no progress--I think there's something wrong with the symmetry of the reman. caliper I got from FCP. I tried FOUR different springs on it, to no avail. If I ever got one to seat, it would pop out within a second of me letting go. Boy, my fingers hurt!

I'm a bit confused at this point. As my wife pressed the brake pedal, I saw noticeable movement from both front calipers, whether they had a spring on or not. I'm not sure I'm sold on the floating caliper design, but still, should they be moving noticeably as pressure is applied and released? I've definitely installed them correctly.

Thanks again,

Nate
--
1997 850, 1979 242GT, 1990 740GL

You should not be able to get the springs on with your fingers, the tension is too high. I normally fit one end on and then use needle nose pliers to get the other end started, then tap it home with a small hammer. Don't bend the spring metal.
No, you should not see the pads move at all. They should have less than 1mm of travel. See the pics from Bay13 as to pin location:

http://volvospeed.com/850fbrake1.php

--
My name is Klaus and I am a Volvoholic.

Well, it worked. You just saved me over a hundred dollars on the ol' master cylinder. Thanks a bunch. I still prefer the old fixed brake calipers over the floating ones, but at least the floaters are working now!

Klaus saves the day again.

If you're ever in eastern Ohio, stop by. I owe you a beer.

Nate
--
1997 850, 1979 242GT, 1990 740GL

I won't get to Columbus again until next August. In the meantime, I'll start drinking more than just 1 :)

Just glad to help,
Klaus
--
My name is Klaus and I am a Volvoholic.

Well hey...thanks Klaus! I guess I WAS trying to put the dumb thing on the wrong side of the caliper bracket. Just when I think I know most things about brakes, I learn something more. Keeps us humble I guess.

I'll see if that helps my braking situation!

Nate
--
1997 850, 1979 242GT, 1990 740GL

Hi Nate, from what I read, it it sounds like brake MC, I imagine you flushed the brake fluid all the way. Did you bleed the wheels in any order? Speaking of that do you know what's the bleed order for V70 FWD? : RR, RL FR, and FL or RR, FR, RL, and FL?
I had this on my 760 turbo - same symptoms, replaced the MC and these brakes are the toughest among all my 3 volvos. I know the newer models use different ABS system, but theoretically should be the same- (air must go out!)
I am thinking if you had problems with calipers- it was because the car didn't get proper maintenance(brake fluid flushed every 2 years) which causes the rubber parts of the brake system to go bad, due to water condensation or whatever the pros call it, so if it didn't then more likely you can't go wrong with changing that MC,
Alex

Thanks for the response Alex, and for the affirming of my suspicions.

The brake bleeding order I used was RR, LR, RF, LF. My British Haynes manual for these cars (In hardcover...but largely unhelpful) says that you should bleed the rears first in either order, then RF, LF.

I guess I must replace one more part on these brakes...for the most part, the car has had great maintenance, but it seems that these brakes were let go a bit.

Nate
--
1997 850, 1979 242GT, 1990 740GL