I jacked the car up on all fours and bled almost two more quarts of Castrol LMA Dot4 brake fluid through the lines but still no brakes. I bled a pint out of the left rear and 3/4 of a pint from the right rear. I taped the calipers with a mallet as I opened each bleed screw. I tapped the distribution block and the rear proportioning valves. I did get some air out but not much at all on any of the calipers. I doubt there could be air in the lines and I should have some pedal at this point, so I think the problem is elsewhere in the system.

I'm going to unbolt the master cylinder again just to make sure it's lined up with the brake booster properly. After that I'm out of ideas. I'm going to talk to the Volvo mechanics at the shop that I use for some repairs to see what they think it could be. I had to rent a car for the wife to drive for a few days until I can talk to the guru's at the Volvo shop. If I can't get it fixed after talking to them, then it will be tow truck time.

I don't know what they would have charged me to do this work, but it's starting to get expensive. I've followed all the proper procedures and still no brakes.
I could flush fluid through the system all day long and still not get a firm pedal. This is really a mystery to me as I've never had this much trouble bleeding brakes.

Any further ideas before I shoot the car (or my wife shoots me!)?

Thanks...!

DeWayne

I read the whole thread, it's so the MC. Just 'cause it comes from a store doesn't mean it was assembled properly. The assembler just has to miss one thrust washer etc and the pedal will pump fluid but not hard against resistance. Return it and try a new one, also look into the booster. Good luck.
--
patrick of montreal, '66/120, '83/245.

just read your ORIGINAL post for help (prior to the rental car).

I would take the master cylinder back to the supplier.

The master cylinder came with an instruction sheet that has a toll free tech assistance phone number on it. I will call them tomorrow and also talk to my contact at the Volvo specialist repair shop. I bled the master cylinder again by cracking the brake lines while my wife pressed and held down the pedal while I closed the line off again. With the engine off, I feel some pedal but it will slowly go to the floor. With the engine running, there is no pedal at all.
I'll find out what's going on pretty soon I hope. It seems like a simple system to be having so many problems getting a firm pedal.

Tomorrow night will be my last attempt to fix it after I talk to some more Volvo guru's and then I'll be forced to throw in the towel and get it towed to the shop. My wife really needs the car back and I'm running out of time and options.


DeWayne

DeWayne,
the problem is in the MC or vac booster connection to the MC.

it is the only common link..

if you haven't overhauled it ($3.00 solution) or replaced it ($30 solution), now may be the time.

the problem is in there somewhere...you should be able to simply open the bleeders and gravity will takeover. when you see the fluid, close the bleeders. that is more than enough to give you a 'hard' pedal.

At the risk of insulting you, I am going to ask you a question.
Are the bleeder screws on the new calipers at the top or the bottom?
I ask this because the last time I had to replace a caliper, Napa had the box marked wrong. I asked for a driver side and they gave me a passanger side.
As I recall, it WOULD have fit on the car; I but realized, at the last minute, that there was going to be a problem and took it back to Napa.

Yep... the bleed screws are on the top. I was very careful to make sure they were put on the correct side. The wife is home now, so I at least have someone to push the pedal for me tonight if she doesn't kill me first.

DeWayne

You're right, front calipers WILL fit on the opposite sides.

I once installed a left caliper on the right side 'cause that was the only decent used caliper I had on a Sunday afternoon -- and work beckoned early Monday morning.

However, I figured out how to fill 'n "pre-bleed" the caliper before installing it, so it made no difference. The brakes were rock hard, worked fine, and I drove that car for 6-7 years with an upside-down caliper.
--
Don Foster (near Cape Cod, MA)

If all of your pistons are back out, push them back in with the bleed screws open. that way there will definitley be no air in the calipers. Close the bleed screw before you stop pushing the pistons in. If I were you I would put the worn out pads back in so you can get the pistons way out first. You can also push air out of the rest of the system that way. To do this leave the bleed screws closed, so that the fluid pushes air back through the MC.
It won't help you now, but you probably could have avoided all of this. when you change a caliper plug the air hole on the resevoir and make sure there is always fluid in it. Disconnect the old caliper and have the new one hanging and ready to attach the line to. Attach the line right away and then bolt it to the car. Open the bleed screws and wait till fluid starts dripping out. No bleeding necessary. The rest of the system is not disturbed so no bleeding is necessary. You can even change the MC without bleeding the system.

The old pads are in the landfill by now. They were worn out past their useful lifespan so I tossed them while atempting to keep my work area clean and almost clutter free. I don't se how there could be any air left in the system at this point. I've flushed almost three quarts of fluid through there following the bleed sequence listed in the Haynes and Bently manuals.

I'm going to dead head the master cylinder again tonight and check the brake booster if I can. The only other possibility is bad brake lines but they are not leaking and the calipers are bleeding fluid ok.

I'll keep trying... and trying... and trying some more...

DeWayne

You don't have to use old pads. Just use a spacer to prevent the piston from pushing right out. I have used a flat crowbar as a spacer to do this (I was unseizing the caliper). But try pushing all the pistons back in. You may push trapped air out the other way. Also the total volume to bleed is much smaller with the pistons in. From what you have said your MC is ok so it must be air. If that does not work you should use the clamps like Don said to try to isolate the problem.
Not trying to insult you, but you did bleed all three screws on the front calipers

Yep... I bled all three bleeder screws on each front side several times.
I even tapped on the calipers with a plastic mallet while the bleeders were open. We just got back from picking up the rental car, so after dinner I'm going to concentrate on the MC and brake booster area again. I spent several hours carefully bleeding all the brake lines in the proper sequence today, so I can't see how any air would be remaining in the hydraulic system at this point.

DeWayne

I have followed the thread and I do realize that you checked the master and that it was new. If I remember correctly I think you even said that you had firm pedal when you blocked the lines or something like that. I still think the problem may be associated or in that master cylinder.
Is the push rod retracting all the way? This will be apparent by observing a slight turbulance in the reservoir after applying and releasing the pedal? Are you able pump fluid with the pedal into the system during the bleeding process or did you use some other bleeding method? If you are not able to pump fluid into the system as in bleeding that is pretty good indicator that the master is bad.

Ive been bleeding the system using a home made pressure bleeder similar to the one from Motive Products. I haven't had anyone available to push the pedal while bleeding, but I'll try it tonight when the wife gets home from work.


DeWayne

Did you try Foster's EXCELLENT sugestion?
--
http://www.fidalgo.net/~brook4/oilslubesfilters.html

Haven't tried the C-clamp test yet as I don't have enough small C-clamps to clamp all the lines. The brake pads on all four wheels have been pushed up against the rotors so I know there is some pressure getting to the caliper pistons. The brake failure warning light is still not on, so if I had a huge pressure loss or differential between the two systems the piston should move I would think. I'm going to get some extra C-clamps or the special brake line clamps that someone else mentioned to try the Foster test.

Thanks for the reminder... my brain got confused from sniffing brake fluid! LOL!


DeWayne