Open Wrench Versus 12 Point

[adallak]

I am about to flush the brake system (probably for the first time in 15 years) and as everybody knows the worst part of the job is loosening the bleeder screws. I would rather use a 12 point end of a combined wrench than the open end to avoid rounding the head. Nevertheless, the 12 point end seems to be much looser than the open end. I realize it applies force to all six points of the hex head, but still kind of scary!

[JimD]

My tool of choice is a 6 point socket, 1/4" drive. If you can let the car sit for 6 or 8 hours with penetrating fluid on the valve threads, you will improve your odds of getting them all removed.

[Cadillac Jim]

I would start with penetrating oil and a 24-hour wait. Then, use the tightest wrench; the fit of the wrench is more important than whether it is 6-point or 12-point. The size is probably metric, not Imperial (mm, not inches), if that helps.

[adallak]

Thank you for the replies. The front is 10 mm and the rear is 8 mm. The front ones have the dust caps on, the rear ones do not have any. The penetrating oil will be there for 24 hours. No rush. I also would prefer 6 point wrrench, but do not have one. Would not hesitate to buy a tighter 6 point since braking a 15 years old 8 mm screw is not hard at all. I just checked and a 8 mm socket works fine. Will try it first.

[Jan Olsson]

WD40 and patience combined with a 6-point wrench. Modern ones are a tighter fit than a 12 point and distributes the force and pressure on the contact surfaces more even. The flats have a slight convex shape and that design is the best to use. A couple of dabs on the screw head with a small mallet can help the corrosion to break loose in the threads and of course a fair amount of heat.

In worst case (that is if you round the head) you'll have to grind/file a new head to get a grip.

Well, you probably know what to do if the screw snaps.

Remove the caliper, drill out the rest of the screw, re-thread to a larger i.d. or use a Helicoil. Be sure to get all the debris out and put it back on.

Good luck. I know that this can be a pain in the butt. Once I had to do just that, drill out to a larger i.d. and make my own bleeding screws because they didn't exist in that dimension at all.

[winterset]

I am about to flush the brake system (probably for the first time in 15 years) and as everybody knows the worst part of the job is loosening the bleeder screws. I would rather use a 12 point end of a combined wrench than the open end to avoid rounding the head. Nevertheless, the 12 point end seems to be much looser than the open end. I realize it applies force to all six points of the hex head, but still kind of scary!

wire brush the bleeder, then spray with liquid wrench. I even tap the bleeder screw with a hammer to work it a little. let it sit soaked in liquid wrench for a while. I once heated the bleeder nut with a torch, then doused it with cold water.

BTW the bleeded should have a factory rubber cap on it to keep it from getting wet.

[adallak]

I am about to flush the brake system (probably for the first time in 15 years) and as everybody knows the worst part of the job is loosening the bleeder screws. I would rather use a 12 point end of a combined wrench than the open end to avoid rounding the head. Nevertheless, the 12 point end seems to be much looser than the open end. I realize it applies force to all six points of the hex head, but still kind of scary!

wire brush the bleeder, then spray with liquid wrench. I even tap the bleeder screw with a hammer to work it a little. let it sit soaked in liquid wrench for a while. I once heated the bleeder nut with a torch, then doused it with cold water.

BTW the bleeded should have a factory rubber cap on it to keep it from getting wet.

Thanks for the reply. The caps are missing. I'll put new screws and will cover them with a generic deep cap filled with some grease. It will cover not only the fitting but also the hex head.

[adallak]

WD40 and patience combined with a 6-point wrench. Modern ones are a tighter fit than a 12 point and distributes the force and pressure on the contact surfaces more even. The flats have a slight convex shape and that design is the best to use. A couple of dabs on the screw head with a small mallet can help the corrosion to break loose in the threads and of course a fair amount of heat.

In worst case (that is if you round the head) you'll have to grind/file a new head to get a grip.

Well, you probably know what to do if the screw snaps.

Remove the caliper, drill out the rest of the screw, re-thread to a larger i.d. or use a Helicoil. Be sure to get all the debris out and put it back on.

Good luck. I know that this can be a pain in the butt. Once I had to do just that, drill out to a larger i.d. and make my own bleeding screws because they didn't exist in that dimension at all.

Thanks Jan. I once snapped the bleeder screw on the front caliper of my 1991 Seville. Replacing the caliper was the most economical way to solve the problem. The rear calipers're expensive, so had to be very careful. DORMAN makes a repair kits for snapped bleeders.

[Ranger]

I even tap the bleeder screw with a hammer to work it a little.

That is probably the best advice yet. It works wonders.

I through away all my 12 point sockets last year and replaced them with 6 points. Should have done it decades ago.

[adallak]

I even tap the bleeder screw with a hammer to work it a little.

That is probably the best advice yet. It works wonders.

I through away all my 12 point sockets last year and replaced them with 6 points. Should have done it decades ago.

12 point wrenches are quite useless IMHO. You can probably use them to unscrew already loose bolts. But then again if you loosened a bolt with something else why would you switch to another wrench.

[Cadillac Jim]

In a tight space a 12-point wrench will let you reset it every 30 degrees as opposed to 60 degrees for a six-point or open end wrench. I don't see a lot of point in a 12-point socket.

[KHE]

I second JimD's recommendation on the 1/4" drive with a 6-point socket. Use plenty of penetrating oil, etc. I always use a torque wrench to tighten the bleeder screws to the proper torque spec. so that I do not overtighten them. Overtightened bleeder screws seem to snap off every time the next time they need to be loosened...

If the rubber caps are missing on the bleeder screws, just use a blob of RTV to make a cap. That will seal out any moisture.

The rear brakes on a Fleetwood Brougham should be drum brakes. A wheel cylinder should be less than 10 bucks if you snap off the bleeder screw.

[adallak]

I second JimD's recommendation on the 1/4" drive with a 6-point socket. Use plenty of penetrating oil, etc. I always use a torque wrench to tighten the bleeder screws to the proper torque spec. so that I do not overtighten them. Overtightened bleeder screws seem to snap off every time the next time they need to be loosened...

If the rubber caps are missing on the bleeder screws, just use a blob of RTV to make a cap. That will seal out any moisture.

The rear brakes on a Fleetwood Brougham should be drum brakes. A wheel cylinder should be less than 10 bucks if you snap off the bleeder screw.

Yes, that's a good news, if I screw up the bleeder, I will just order and replace the wheel cylinder. Let's see.

[BodybyFisher]

Adallak, I would use a 10 MM IN LINE flare nut wrench that 'wraps' the fitting to minimize rounding the nut, see the type here, but the 6 point socket is also good

http://www.sears.com...=3&blockType=G3

[adallak]

Okay, Gents...need your help. I have removed the right rear bleeder screw - a little torch did the trick. So, it is a good news. Now, I try to bleed the system manually without a helper using a stick between the brake pedal and the driver seat. I have described that method a few years ago. Power option helps to move the pedal slowly and keep in the position while I play the with the screw.

The PROBLEM is that it looks like some air gets in the system through the threads of the bleeder screw... Can I use some grease to prevent that? I am stuck right now.

[BodybyFisher]

You mean when you tighten the bleeder screw and let the pedal up you are sucking air back into the system?

Make sure you have fluid in the master cylinder

[adallak]

You mean when you tighten the bleeder screw and let the pedal up you are sucking air back into the system?

Make sure you have fluid in the master cylinder

Yes, Mike, that's what I think. The master cylinder reservoir is full. I could definitely see what's going on if there was a helper, but now I have to just guess. Okay, I'll probably just flush as much as it takes. Take it for a test drive and later may try to bleed again. The good news is there will be all new bleeders installed.

[BodybyFisher]

It sounds like it is not tightening up properly, check the threads and the mating surfaces look for rust or sediment stopping full closure

[adallak]

It sounds like it is not tightening up properly, check the threads and the mating surfaces look for rust or sediment stopping full closure

The original screw was in good shape and is similar to new one, so I think the mating surfaces are fine.

Here is another question, should the wheel cylinder pushroads bent like that? Drum brakes are new to me. Sorry, for a dumb question!

Okay, something is wrong. The rear wheel cylinder boot fell out of the cylinder and the fluid is leaking down when I started the engine and pressed lightly the brake pedal. The drum was OFF. The pedal went all the way down.

Before it happened I could easily move the pushroad and even take it out if I wanted. What shall I do next?! darn drum brakes. lol

UPDATE. Took the shoes off so I could at least put back the drum and the wheel. The piston looks okay, there was a lot of sludge inside the wheel cylinder. What is that? Can I still put the cylinder together or should consider a replacement?

[BodybyFisher]

No they should not, look like that and its doubtful you could get the wheel on. Pull the brakes toward you, and seat them so that the round barrel springs on the side are squared up.

[adallak]

No they should not, look like that and its doubtful you could get the wheel on. Pull the brakes toward you, and seat them so that the round barrel springs on the side are squared up.

Mike, I took the shoes of just to be able to put the wheel back and lower the car. It is about to rain... Something was wrong with that drum brake, made noises, parts seemed to be loose... Now I have to investigate, a learning curve! lol Probably will buy another wheel cylinder.

[KHE]

Something is definitely not right. The pushrods should be parallel with the wheel cylinder. Was it that way when you removed the drum?

If you could see sludge, that is brake fluid mixed with brake dust - sounds like it is only a matter of time before the wheel cylinder starts leaking brake fluid on the backing plate, shoes, etc.

[KHE]

You mean when you tighten the bleeder screw and let the pedal up you are sucking air back into the system?

Make sure you have fluid in the master cylinder

Yes, Mike, that's what I think. The master cylinder reservoir is full. I could definitely see what's going on if there was a helper, but now I have to just guess. Okay, I'll probably just flush as much as it takes. Take it for a test drive and later may try to bleed again. The good news is there will be all new bleeders installed.

You need to make sure the new bleeder screw is the same as the original or they may leak even when tightened.

[adallak]

Something is definitely not right. The pushrods should be parallel with the wheel cylinder. Was it that way when you removed the drum?

If you could see sludge, that is brake fluid mixed with brake dust - sounds like it is only a matter of time before the wheel cylinder starts leaking brake fluid on the backing plate, shoes, etc.

Can I use the same cylinder after cleaning the mess? The pushrod and the piston have some corrosion, but nothing major.

Now, I am pretty sure I found the source of ticking noise the rear brakes made. That loose pushrod could make that noise. The question is why it was loose in the first palace?

[adallak]

You mean when you tighten the bleeder screw and let the pedal up you are sucking air back into the system?

Make sure you have fluid in the master cylinder

Yes, Mike, that's what I think. The master cylinder reservoir is full. I could definitely see what's going on if there was a helper, but now I have to just guess. Okay, I'll probably just flush as much as it takes. Take it for a test drive and later may try to bleed again. The good news is there will be all new bleeders installed.

You need to make sure the new bleeder screw is the same as the original or they may leak even when tightened.

I compared them - they are identical. I believe the source of air leak was the wheel cylnder.