I just replaced, Front calipers, SS Lines, Master Cylinder, Pads, Rotors. Its an 87 TII. I've bled the brakes maybe 6 different times and bench bled the cylinder before I put it on. They're ceramic pads and OE rotors in the rear, Powerstop in the front. I've got some speed bleeders coming in and I just can't seem to get them bled very well. There's still a lot of brake travel and not much stopping power. Anyone have any ideas? I've heard of bleeding the proportioning valve but I haven't the slightest idea how to do that. Any help is greatly appreciated. I've put about 5 32oz brake fluid bottles thru the system. Thanks



Chris

 

And yes I ******* searched.

 

umm... youre master cylinder could be going out. if its not leaking externally, the seal on the piston itself could leak- this would allow fluid back into the reservoir when you push the brakes, leaving you with low pressure in the lines.
when you bleed, is the fluid coming out nice and bubble free? or are you having the bleeding problem where theres constantly bubbles?

 

New Master Cylinder as well.

 

I recently got a bad 929 MC right from a dealer. Wouldn't set up at all. Try putting your old one back in if it's serviceable.

 

Already sent back as a core.

 

If it's merely air in the lines rapid pumping of the brake pedal will bring the pressure up. If this is the case the system isn't bled properly. I'd bench bleed the master again if this happened.

If the pressure doesn't come up when pumping the brakes then you have some sort of seal problem somewhere in the brake system.

 

Pumping the brakes brings the pressure slightly. I think my problem is insufficent bleeding. I'm going to drive the car around for a few days and when my speed bleeders get here then she'll get another quart of fluid thru the system. My new pads did not come with Shims. I placed the old crusty worn out ones back on and of course sprayed disc brake quiet on the back of the pad and then on the shims once they were on. The compression of the shims could be part of the brake pedal travel because they were sort of rusty. Do I need shims on the front if I have sprayed the pads with just the disc quiet stuff??? I am considering taking them off but I'm not sure yet. One of the sales reps from Wagner told me that their pads didn't need shims, but the pads on the front are not wagner although they seem to be composed almost identical.

 

I just went on the brake pads website and they are supposedly shimmed already. I'm gonna take everything apart again and ditch the shims, rebleed the system for the 10th time and maybe we'll have some serious stopping power. Oh and I ditched the stock brake cooling duct for some 4inch flex pipe from lowes. I'll try to post pics.

Chris

 

Sometimes that alone will help. I did a MC on my integra and had little pressure afterwards. After a few days of driving it stiffened up enough that I never bothered to bleed it again.

 

I recently replaced my entire brake system, and I also ran into the same problem your having. Make sure that you bleed both of the bleeders on the rear calipers, because there are two. I'm sure you did, but it took me 4 bleed sessions to figure that out. Come to find out i had a bubble that the bottom bleeded was able to expell, and after that the brakes felt normal. Hope that helps.

 

The only tip I can offer is that most cars have a brake bleeding sequence. That is, you have to do each wheel in a certain order to be sure you get all the air out. I don't know what the sequence is for your car.

 

http://autorepair.about.com/od/brake.../aa091804f.htm

Wheel Bleed Sequence:

If you are bleeding the brakes manually, the sequence is RR-LR-RF-LF. If you are pressure bleeding, bleed the front brakes together and the rear brakes together.



http://www.hispecmotorsport.co.uk/bleeding_brakes.htm

1 We would suggest you work in the following sequence:
a) Right-hand rear wheel
b) Left-hand rear wheel
c) Right-hand front wheel
d) Left-hand front wheel



http://lasvegas.craigslist.org/aos/195071533.html

BRAKE LINE BLEEDING SEQUENCE
Application Sequence
Acura & Honda LF, RR, RF, LR
Audi & Volkswagon (1) RR, LR, RF, LF
BMW (2) Longest Line First
Chrysler Corp. Imports
Colt & Colt Vista LR, RF, RR. LF
Models W/Load Sensing Proportioning Valve RR, LR, RF, LF
All Others (3) RR, LR, RF, LF
General Motors Imports
Chevrolet Spectrum LF, RR, RF, LR
Chevrolet Sprint LR, RF, RR, LF
Isuzu
I-Mark, P'UP & Trooper II (4) LF, RR, RF, LR
Impulse RR, LR, RF, LF
Jaguar (4) LR, RR, Front
Mazda Longest Line First
Mercedez-Benz Longest Line First
Mitsubishi
Cordia, Tredia LR, RF, RR, LF
All Others RR, LR, RF, LF
Nissan
Maxima RR, LR, RF, LF
Pickup Master Cyl., Comb Valve, Longest Line First
Pulsar & Sentra RR, LF, LR, RF
200SX & 300ZX LR, RR, RF, LF
All Others Master Cyl., Longest Line First
Peugeot (5) Longest Line First
Porsche (6) LR, RR, RF, LF
Renault Longest Line First
Saab LR, RF, RR, LF
Subaru Master Cylinder, FR, RF, RR, LF
Suzuki LR, RF, RR, LF
Toyota Longest Line First
Volvo (7) RR, LR, RF, LF
(1) Before bleeding rear brakes, push brake pressure regulator in direction of rear axle.
(2) If equipped with 3 bleeder valves on each front caliper, bleed lower inboard valve first, then other 2 simultaneously.
(3) Pickup models do not require bleeding of RR
(4) Engine running at idle speed
(5) If pressure tank is used, bleed all wheels simultaneously.
(6) If equipped with inner and outer caliper bleeder valves, bleed outer valves first, then inner valves.
(7) Raise rear wheels a few inches higher than front wheels. Bleed all 3 valves simultaneously.Clint Hough is an author and web site publisher on imported car parts and you can get all your Mercedes Benz Parts from our on line catalog for all your Mercedes Car Parts needs at Imported car parts.com.


http://www.popularmechanics.com/auto...tml?page=2&c=y

 

Yea I think driving the car around helped some and of course I got all my speed bleeders in and I'm going to bleed them again. I put shims back on the front pads and once I looked at the website where I bought the pads from, they said they do not need to be shimmed. So I'm gonna rip those out and bleed the system again.

Neat fact. You can buy the rear speed bleeder screws from advanced auto parts. They list them in thier HELP! section. But the also list the Front Screws to be a 7mm on both the TII and the 3rd gen, Which is wrong. They are an 8mmx1.0. I bought the front ones from speed bleeder.com.

Front's 8mmx1.0
Rears 7mmx1.0

 

Well I put my new bleeder screws in last night and ripped those shims out. Ran another 64oz of fluid thru the system, and BAM, exactly like they should be. I'm very happy with the outcome. There was a lot of bubbles that came out of the pass side front so I think that had a lot to do with it. So here's the moral of the story gentlemen....Bleed it, Drive it, Bleed it, Drive it, Bleed it, Drive it, Bleed it. Oh and get some speed bleeders cause they rock. I'll see if I can get some pics of my 4inch brake cooling ducts here soon.

Chris

 

What I think made the most difference: When I was bleeding them with the speed bleeders, every now and then I would give them like 5 hard punches, all the way to the floor. Then do like 10 slow pumps all the way to the floor, thats when the most bubbles came out. I think the rapid forcing of the fluid helped loosen up a lot of the bubbles that had been hiding in spots. Mind you I even used one of those mityvac vacuum pumps when I was trying before and it had no effect whatsoever. And if you're gonna replace the Master Cylinder, Make sure it comes with the resivior, because I broke mine trying to get the damn thing off, and almost wasn't able to get the new one in.


Chris

 

I got a good tip on bleeding brakes from Zeckhausen Racing.

Tap each caliper with a rubber or wooden mallet prior to bleeding. This will loosen up the mico bubbles that cling to the walls inside the caliper.

To put it another way......

1. Beat the **** out of the caliper
2. Pump the brake pedal & hold.
3. Open the bleeder quickley & close it prior to the pedal reaching the floor.
4. Repete each step 4-5 times, check fluid level. Move on to the next caliper.

As noted in earlier posts start with the right rear caliper.

I would not recommend driving around at all with air in the system.

 

Did the mallet trick and it didn't do anything as well.

 

Get an air powered vacuum bleeder with the reservoir.

Sit the reservoir on top of master cylinder and open valve (keeps MC full of fluid). Raise vehicle or crawl under. Attach air hose to vacuum bleeder and turn on. Stick hose over nipple and open bleed screw. Sit back and drink a beer. Close bleed screw.

Repeat 3 more times.