Broken bleeder screw

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I was helping a friend bleed the brakes on her 1993 saab 900. On one of the bleed screws (left rear), I noticed the rubber cover was missing. I sprayed penetrating oil, then attempted to loosen it. The screw broke off! The other 3, no problem. I tried to extract the broken bleed screw with a screw extractor, and replace it with a new one. Sprayed lots of penetrating oil again. But the screw extractor broke too! I tried to drill a new hole in the bleeder screw, but I found that virtually impossible bcos the screw is so small. Is it safe to drive around with a broken bleed screw (the hole is plugged up with the broken screw extractor)? The last time the brakes were bled was 2 years ago, will there be problems say few years down the road?
 
It's usually at this point that the caliper is exchanged for a rebuilt unit. Yeah, you could probably get away with leaving the old caliper on there, as long as the caliper otherwise functions properly. The choice is yours.

As a side note, I've always wondered if somebody has a good preventive measure for keeping bleeder screws from freezing in the caliper. Plus, I would like to vacuum bleed the brakes with my vacuum bleeder, but I can't because of the air that works its way past the bleeder screw. I recently put some rtv on the threads of bleeder screws on my last brake job. I won't know until later if this does the trick.
 
I would replace it.. and not fool with questionable brakes. And if it kills somebody you could also have legal liability.

Is it rear disc brakes ?

Here, a quick scan of a parts store website showed a rebuilt caliper for $53. (I say here because your sig location says Singapore. In Singapore, good luck. Long way from Sweden !)
 
If you somehow managed to get the air out, and have a good, firm brake pedal now, there won't be any problem until you work on the system and need to bleed it again. If the brake pedal is soft or spongy, you must get the bleed screw out. Otherwise, I would leave well enough alone for now.

The broken off Easy Out is a classic problem. The original problem wasn't that you couldn't get a grip on the bled screw, but that it was frozen. It is much easier to deal with that problem before you twist off the bleed screw and create another one. If it doesn't seem to be coming with a box wrench or 1/4'' drive socket, don't just pull harder. Often pounding on it with a small ball peen hammer, will flex things enough to allow it to be turned out. If not, the next step is to heat it with a torch and cool it quickly. Be careful what else you heat and take it easy, very easy on aluminum parts. Those cases where an Easy Out works, usually are do to the heat and vibration of drilling the hole. If you apply the heat and vibration before needing the Easy Out, you can skip that whole step. Penetrating oil alone, seldom solves the problem. It also avoids buying a new bleed screw. Usually they are not expensive, but nobody may be open that has the right one in stock. Some of this hammering and heating is best done on the bench. Rubber parts not removed before heating much will be ruined. Bottom line, don't bust the **** thing off in the first place.

I strongly suggest removing bleed screws, cleaning them up, and coating with a silicone grease such as Sylglide. Anti seize may be OK, but I am paranoid about applying any hydrocarbon to any brake part.
 
Does anyone have experience with treating bleeder screw threads for vacuum bleeding? I only have a 10% success rate where no air gets past the threads. Most of the time I'm drawing air past the threads.
 
quote:

Originally posted by Kestas:
Does anyone have experience with treating bleeder screw threads for vacuum bleeding? I only have a 10% success rate where no air gets past the threads. Most of the time I'm drawing air past the threads.

I am surprised at that. Usually finger tight works for me. Perhaps it is the generous coat of Sylglide I use after cleaning up the bleed screw on the wire brush wheel.
 
Kestas, I've had good results over the years using just a bit of anti-seize on the bleeder threads.
Just got some speed bleeders to put on my daughter's (soon to be her mother's) car.
 
first, you need to replace that caliper, brakes are the one thing that should never be cheaped out on. to prevent air leakage past the bleeder and keep them from seizing, I wrap the threads with teflon tape.
 
The saab technician took a look at it and advised to just leave it. With the screw extractor plugged in there, it is as good as sealed for life. He suggested to bleed by the brake hose instead. True enough, I tried it and it works! It's not 100% but it's close to 99% bled bcos the distance from the brake hose screw to the bleed screw is about 15mm.

Hope this tip helps some of you with broken bleed screws.
 
I have done that with a wheel cylinder. It was part of my learning curve. My learning curve didn't include technician's training. Technicians seem to give up on projects mechanics prided themselves on fixing. When I worked for the old school type, frequently people brought in wheel cylinders and calipers with frozen bleed screws. We always got them out, except maybe sometimes with aluminum calipers that too much heat would destroy. He had nasty, negative things to say about people that broke off Easy Outs in them. He much preferred to start with an unbroken bleed screw.

If bleeding by the hose doesn't work, it is a choice between time and money on rebuild/replace the caliper. It will have to come off and go the the bench. The screw can be freed using heat and impact. Once freed, you may need to apply a punch tangentially to it to remove it. Availability of parts may also influence you decision.

Your better drill bits will cut an Easy Out that has been heated red hot and allowed to air cool.
 
at the very least take that caliper off and have a machine shop remove the bleeder. I don't care what the tech said, that isn't a safe condition.
 
Either the car has a reasonable pedal now or not. If so, the brake fluid can't tell the condition of the bleed screw. All it sees is the tip still firmly plugging the end of the bore. The screw is not going to vibrate out. I once drove a car for years with a broken bled screw with no problems.

Only if the pedal is still soft and spongy, do you need to do more now. Don't be panicked into expensive work you don't have to do. Calipers, or at least the rubber rings inside, don't last forever. Eventually it will need rebuilt or replaced. Worry about the bleed screw then.
 
Well, I managed to break off the screw on one of the rear drums of my 87 Accord. Since I didn't even get a partial turn off the screw, I just threw up my arms, and called it a day. The screw was clearly tight, so no air was going in, and no fluid was coming out. So I just jammed some RTV sealant in the hole for good measure, and never had anything come of it since.
So if the screw turned, then you need to worry about it, but if the screw never turned, then it's nothing to worry about really.
 
I think the question of drum or disk was not answered. If it's a drum, my old trick was to GENTLY use a feeler guage to push down the top of one of the wheel cylinder seals 'til fluid comes out. Had to do this on an old Bonneville. Worked perfectly.

Dave
 
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