Brake Question!!

[Supergeek]

I have a '76 2002 with Irelands big brake kit, SS brake lines and a Tii master cylinder. No matter how much I bleed the fluid I cant get any brake pressure. I even purchased a one man pressurized brake bleeder kit from Bav Auto, and bled. I got a little pressure after pumping the brakes, but as soon as I stopped pumping, the pressure went away. I talked to the guys at Ireland and they said the master cylinder or slave cylinder, or both, could be bad. I checked the slave and it looks ok. When I replaced the stock master with the Tii master, thats when the problems started. My question is this, what else should I check before purchasing a new master cylinder? Is there anything else that could be causing this problem? When I bleed the brakes I hardly get any air bubbles, so I think there is no air in the brake system. The booster is ok, worked fine with my old brakes. I will be moving soon and want to take my 02 with me!! Any info will be GREATLY appreciated! Thank You!

David

[uber02]

OH MY GOD!!!

I am having the EXACT same problem. I posted a question about it a little earlier today. In what order did you bleed the front calipers? I just assumed outter inner top but I am wondering if that is incorrect. I hope I don't have a bad master, it was working fine before I started this project.

Thanks,

Emery

[Supergeek]

OH MY GOD!!!

I am having the EXACT same problem. I posted a question about it a little earlier today. In what order did you bleed the front calipers? I just assumeed outter inner top but I am wondering if that is incorrect. I hope I don't have a bad master, it was working fine before I started this project.

Thanks,

Emery

My master cylinder was working fine too! I dont have my BMW manual with me but I think the order is inside top, inside bottom and outside middle...........I think?

David

[Pierre]

The slve cylinder is for a clutch.

Did you bleed the fronts and the rear?

Any leaks?

If nor, you probably need a new master.

Did you use a new master? If so, you should get it replaced under warranty.

There is nothing to look in a master cylinder. You could have a factory defect but there is no way to tell without installing it.

[Supergeek]

The slve cylinder is for a clutch.

Did you bleed the fronts and the rear?

Any leaks?

If nor, you probably need a new master.

Did you use a new master? If so, you should get it replaced under warranty.

There is nothing to look in a master cylinder. You could have a factory defect but there is no way to tell without installing it.

Hey, Pierre. The guys at Ireland told me it could be the slave because it is connected to the brake resevoir. And if its leaking, air could be entering through the slave and into the master. But, it looked okay to me. The Tii master cylinder was bought new months ago, so I dont know if its still under warranty. Ive checked all my brake lines and I have seen no leaks. I also bled them in order.......RR, LR, RF and LF. Im STUMPED!!!!! Thanks!

David

[Mike Self]

Not gonna happen...the only connection between the two is the brake fluid reservoir, which is (1) not under pressure and (2) is the highest point in the entire hydraulic system. The fluid may interchange between the systems (but not likely) but they're not pressurized together. In fact, early 2002s had separate reservoirs for clutch and brake systems.

From what you describe, presuming

1. you're bleeding all four wheels, starting with the furtherst from the M/C

2. you're bleeding all the front caliper nipples

3. you're not losing brake fluid anywhere (as from a leak)

I'd have to go with a defective M/C. They can pass fluid internally without leaking externally; I've had several do that over the years, including one that had less than 30k.

If the M/C is new, you should be able to return it for a non-defective one...

One thing we often forget is that parts that are new out of the box can be defective!

cheers

mike

[Mikesmalaga72]

Did you bench-bleed the master cyl prior to installing? Air could still be trapped in there. Good luck.

[Emyers]

You don't have the calipers mounted upside down, ie left on right side and vice versa. Bleed nipples should be pointing up. Has happened before....

Earl

74 2002Lux

72 Volvo 1800ES

02 Roadster

[uber02]

Do you have the problem with the pressure differential switch like I do? mine has caused the brake warning light to come on and I am not sure whether it needs to be manually reset or not.

Thanks,

Emery

[Supergeek]

Did you bench-bleed the master cyl prior to installing? Air could still be trapped in there. Good luck.

How do I do that?

David

[Supergeek]

Do you have the problem with the pressure differential switch like I do? mine has caused the brake warning light to come on and I am not sure whether it needs to be manually reset or not.

Thanks,

Emery

Hi, Emery. My switch was unplugged. And I have no brake light warning problems. The plastic thingy were the switch connected to the diff is actually broken....................hmmmm..............I wonder if thats causing this.

David

[fast2002]

I just solved the same problem after several weeks of pumping and pumping the brakes trying to get the air out.

I replaced the MC and forgot to bleed the MC. I bled the MC on the car by gravity feeding, first open each line separately to the MC until you see fluid flowing, close the line and go to the next line.

Next, have one to pump the brakes and hold them to the floor pushing the pedal while you open the bleeder valve. Start at the farther valve from the MC and work to the driver's side.

Remember to top off the reservor between bleeder valves.

Repeat this twice....

Let me know what happened

[uber02]

Well I just spent another 2 hours pumping the brake pedal. I do think I might be getting somewhere though, . . . maybe. At this point it seems I am now down to the last bleeder (top bleeder on the driver side caliper) and I have been pumping on it for an hour and there are still bubbles coming out. I am wondering if the master cylinder is indeed bad though becuase it is begining to make a good amount of noise sometimes as I push the pedal through it's travel, kinda a squeeky/groany noise. Also I still have the brake warning lamp on from the pressure differential switch. Does anybody have any pointers as to the specifics of that warning lamp and do you have to manually reset it? Is my master cylinder bad?

Thanks,

Emery