Open Wrench Versus 12 Point

[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.

Honestly, I did not pay attention whether the pushrods were parallel when I took the drum off. But when I tried to put the drum back and it would not go, I have noticed the pushrods were not parallel and it looked strange to me.

[JimD]

Can you take another picture? I would like you to back away a little to include the top of the backing plate and the top of the shoes in the shot. Including the top of the axle flange for reference.

Those shoes are not in the correct position somehow and the top end of the shoes might not be seated properly on the self-adjuster wheel.

Also take a shot of the bottom center pivot pin for the shoes. Include the bottom edge of the backing plate and the bottom of the axle flange for reference.

[adallak]

Can you take another picture? I would like you to back away a little to include the top of the backing plate and the top of the shoes in the shot. Including the top of the axle flange for reference.

Those shoes are not in the correct position somehow and the top end of the shoes might not be seated properly on the self-adjuster wheel.

Also take a shot of the bottom center pivot pin for the shoes. Include the bottom edge of the backing plate and the bottom of the axle flange for reference.

Jim,

Unfortunately, I had to take off the shoes and lower the car. It's raining here. So, no pictures. I was kind of pressed for time - taking off all the bleeder screws, bleeding without a helper, servicing as needed the brakes , etc. All should have been done in a couple of hours.

Now, the wheel cylinder was a suspect from the beginning because the rear right brakes would make noises and get pretty hot compared to the left one. It seemed strange to me that I could move easily the pusrods and even take one off with fingers....

Does it make sense to use the original wheel cylinder, seals, pushrods or I should get a new one. For some reason, I believe something was wrong with the cylinder. As I already mentioned, there was some sludge inside the wheel cylinder and it did not smell good.

[JimD]

....Now, the wheel cylinder was a suspect from the beginning because the rear right brakes would make noises and get pretty hot compared to the left one. It seemed strange to me that I could move easily the pusrods and even take one off with fingers....

Something is not making sense and I suspect the shoes were out of position which would impact the self-adjusting mechanism.

Does it make sense to use the original wheel cylinder, seals, pushrods or I should get a new one.

A new wheel cylinder would be good since there is reason to suspect the bleeder threads in the one you have. And if you are certain all the springs and clips and shoe positioning pieces are there, the wheel cylinder is all you need.

As I already mentioned, there was some sludge inside the wheel cylinder and it did not smell good.

The sludge is not unusual; the wheel cylinders are the lowest point in the system and that is where the absorbed moisture would gravitate to. Can't speak to the smell; brake fluid smells like brake fluid which is unmistakable.

[adallak]

....Now, the wheel cylinder was a suspect from the beginning because the rear right brakes would make noises and get pretty hot compared to the left one. It seemed strange to me that I could move easily the pusrods and even take one off with fingers....

Something is not making sense and I suspect the shoes were out of position which would impact the self-adjusting mechanism.

Does it make sense to use the original wheel cylinder, seals, pushrods or I should get a new one.

A new wheel cylinder would be good since there is reason to suspect the bleeder threads in the one you have. And if you are certain all the springs and clips and shoe positioning pieces are there, the wheel cylinder is all you need.

As I already mentioned, there was some sludge inside the wheel cylinder and it did not smell good.

The sludge is not unusual; the wheel cylinders are the lowest point in the system and that is where the absorbed moisture would gravitate to. Can't speak to the smell; brake fluid smells like brake fluid which is unmistakable.

Now, I think it was not bleeder threads but rather the faulty wheel cylinder, leaking air in. Will get a new cylinder (not OEM unfortunately) and will report back tomorrow. Thank everybody for the input. The parts were covered with brake dust, but I could not see any serious rust.

[JohnnyG]

If you pushed on the brake pedal with the drum off, that would immediately blow a piston out of drum brakes, it's a definite no-no. I'm not saying that the wheel cylinder may not have been bad before though. One thing that can cause this on drum brakes is if the automatic adjuster was either installed wrong or otherwise not working. I can remember drum brakes very well, and the condition you describe was not uncommon if somebody put them together incorrectly at one time or another, or if an adjuster cable snapped or something.

It was very common to rebuild drum brake cylinder while they were still on the car. I still own a brake cylinder hone. The process was to clean everything up, and take the pistons completely out of the cylinder. The hone, on the end of a drill, was inserted and spun until the cyinder bore was cleaned and rust free. Then new "cups" were installed and everything put back together. The last thing to do was to bleed the brake cylinders. Very inexpensive process. A rebuild kit was less than $10.00 back then!

[adallak]

If you pushed on the brake pedal with the drum off, that would immediately blow a piston out of drum brakes, it's a definite no-no. I'm not saying that the wheel cylinder may not have been bad before though. One thing that can cause this on drum brakes is if the automatic adjuster was either installed wrong or otherwise not working. I can remember drum brakes very well, and the condition you describe was not uncommon if somebody put them together incorrectly at one time or another, or if an adjuster cable snapped or something.

It was very common to rebuild drum brake cylinder while they were still on the car. I still own a brake cylinder hone. The process was to clean everything up, and take the pistons completely out of the cylinder. The hone, on the end of a drill, was inserted and spun until the cyinder bore was cleaned and rust free. Then new "cups" were installed and everything put back together. The last thing to do was to bleed the brake cylinders. Very inexpensive process. A rebuild kit was less than $10.00 back then!

Thanks for the reply. Everything was covered with lots of brake dust and definitely did not work properly because the related rim would heat up more than the left one. Will put a new wheel cylinder since it is only $10. Should have paid more attention probably, but was in a hurry to finish all flushing before it rains. I'll report back tomorrow. Still have to remove remaining three bleeder screws. I am sure nobody touched the brake system for 15 years. The brake fluid was black and had some suspended particles.

[JimD]

This drum brake issue is refreshing my memory. I think the last time I touched a drum brake system was around 199-something. Yikes!! My age is showing.

Does anyone else remember hand cranks, driver-adjusted spark advance, and gravity feed fuel tanks?

[BodybyFisher]

How about vacuum driven wipers? We had them in a 49 Mercury. Step on the gas they stopped

[Bruce Nunnally]

The windshield washer system on the Porsche 914 ran off the pressure in the spare tire. Wash your windscreen too often, you'd have a flat spare.

[adallak]

When I took off that darn drum I did not realize I opened Pandora's box of old sweet memories!

[JimD]

We now return you to adallak's drum brake programming.

[adallak]

We now return you to adallak's drum brake programming.

Jim, I enjoy that off-topic discussion. How would I know Porshe used spare tire for windshield washer!? lol

[Cadillac Jim]

It's normal for the wheel cylinders to have some sludge in the bottom of the cylinder, particularly if they have been on the car for a long time.

Since you have removed the cups from the wheel cylinder, it's best to rebuild it to make sure that the sludge doesn't get under the pistons and make the wheel cylinder leak. That operation consists of getting a wheel cylinder rebuild kit, which is cups, pistons, and boots, cleaning out the wheel cylinder to remove any shellac or oxidation on the inside, and reassembling the wheel cylinder and pistons with boots.

All that's left for a complete brake job is to take the drums and shoes to a machine shop (Pep Boys, some NAPA stores, local brake shop or chain, etc.) and get the drums turned and exchange brake shoes with new linings, ground to match the drum diameter, and reassemble everything with new brake shoe retainers, return springs, and any other miscellaneous hardware that comes with a brake job kit. Adjust each brake to the same clearance, and you're done. If you do one side, do both to make sure the car doesn't pull to one side on braking when you're done.

WARNING -- the installation of the brake shoes, engagement with the wheel cylinder pistons, and proper installation of the return springs, self-adjusters, actuation levers, etc. all are essential for safety. I strongly suggest that you pull the drum on the other side, take a picture, print it as a mirror image, and use it as a guide to put back the brakes on the side where the wheel cylinder has pushed out.

[adallak]

It's normal for the wheel cylinders to have some sludge in the bottom of the cylinder, particularly if they have been on the car for a long time.

Since you have removed the cups from the wheel cylinder, it's best to rebuild it to make sure that the sludge doesn't get under the pistons and make the wheel cylinder leak. That operation consists of getting a wheel cylinder rebuild kit, which is cups, pistons, and boots, cleaning out the wheel cylinder to remove any shellac or oxidation on the inside, and reassembling the wheel cylinder and pistons with boots.

All that's left for a complete brake job is to take the drums and shoes to a machine shop (Pep Boys, some NAPA stores, local brake shop or chain, etc.) and get the drums turned and exchange brake shoes with new linings, ground to match the drum diameter, and reassemble everything with new brake shoe retainers, return springs, and any other miscellaneous hardware that comes with a brake job kit. Adjust each brake to the same clearance, and you're done. If you do one side, do both to make sure the car doesn't pull to one side on braking when you're done.

WARNING -- the installation of the brake shoes, engagement with the wheel cylinder pistons, and proper installation of the return springs, self-adjusters, actuation levers, etc. all are essential for safety. I strongly suggest that you pull the drum on the other side, take a picture, print it as a mirror image, and use it as a guide to put back the brakes on the side where the wheel cylinder has pushed out.

Thanks, Jim. I will rather try to replace the both wheel cylinders with new ones as they are inexpensive. The brake hardware (springs, plates, etc.) is in good shape. Will try to put all together. Have done much more complex repairs, should not be a problem. I am sure th eright rear brake did not function properly, so it is probably a good thing I went farther then I initially intended.

[KHE]

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

I would replace the wheel cylinder. Like I said before, it will most likely leak soon if it hasn't started already, that will make a mess out of everything and you'll be doing the job all over again.

It was very common to rebuild drum brake cylinder while they were still on the car. I still own a brake cylinder hone. The process was to clean everything up, and take the pistons completely out of the cylinder. The hone, on the end of a drill, was inserted and spun until the cyinder bore was cleaned and rust free. Then new "cups" were installed and everything put back together. The last thing to do was to bleed the brake cylinders. Very inexpensive process. A rebuild kit was less than $10.00 back then!

I used to rebuild by wheel cylinders too - a rebuild kit was $3.00-5.00 last time I rebuilt a wheel cylinder. Wheel cylinders produced in the last 15 years cannot be rebuilt as they are no longer heat treated to harden the bore. A ball tool is pulled through the bore during manufacturing which work hardens the bore. This is enough to provide a hard enough surface on the bore. If this type of cylinder is honed, the brake hone breaks through the work hardened bore and it will wear out and start leaking in a very short time.

[Cadillac Jim]

Rebuilding wheel cylinders begins with stripping them and the critical step of removing oxidized brake fluid from the bore. This is a very critical step because without it the rebuilt wheel cylinder will leak. The procedure in my father's brake shop in the 1950's and 1960's was to use a wheel cylinder hone, three strips of whetstone in an expanding lattice on a flexible cable driven by an electric drill. The DIY solution is hand-sanding with 400 grit wet sandpaper. This may result in residual filings in the system so if you are not comfortable with total removal of filings you should remove the wheel cylinder before this step and wash it out thoroughly before reassembly. Also, don't over-do it because any significant increase in the bore will cause the piston cups not to seal.

GM dealers historically do not want to provide the Goodwrench warranty for rebuilt wheel cylinders. A Goodwrench brake job that includes wheel cylinders will result in new wheel cylinders.

[adallak]

Do you think the same sludge could build up in front brake calipers as well?

[KHE]

Rebuilding wheel cylinders begins with stripping them and the critical step of removing oxidized brake fluid from the bore. This is a very critical step because without it the rebuilt wheel cylinder will leak. The procedure in my father's brake shop in the 1950's and 1960's was to use a wheel cylinder hone, three strips of whetstone in an expanding lattice on a flexible cable driven by an electric drill. The DIY solution is hand-sanding with 400 grit wet sandpaper. This may result in residual filings in the system so if you are not comfortable with total removal of filings you should remove the wheel cylinder before this step and wash it out thoroughly before reassembly. Also, don't over-do it because any significant increase in the bore will cause the piston cups not to seal.

GM dealers historically do not want to provide the Goodwrench warranty for rebuilt wheel cylinders. A Goodwrench brake job that includes wheel cylinders will result in new wheel cylinders.

Jim,

You can't rebuild a wheel cylinder that has been produced in the last 15-20 years or so. You could, but it won't last.

[JohnnyG]

adallack, one last tip from me. Don't use petroleum based solvents on parts that will be contacted by brake fluid. The proper solvent (after brake clean sprays of course) is alcohol, either isopropyl or methanol (poison) based. Also do not use any type of oil inside the wheel cylinders, or grease for that matter. Just use brake fluid if you need to lubricate something inside the system.

Sorry for firing up the way-back machine!

[adallak]

adallack, one last tip from me. Don't use petroleum based solvents on parts that will be contacted by brake fluid. The proper solvent (after brake clean sprays of course) is alcohol, either isopropyl or methanol (poison) based. Also do not use any type of oil inside the wheel cylinders, or grease for that matter. Just use brake fluid if you need to lubricate something inside the system.

Sorry for firing up the way-back machine!

Thank you for the tips. Got new cylinders. Will do tomorrow if the weather permits.

[Cadillac Jim]

KHE -- thanks for the heads-up about newer wheel cylinders being non-rebuildable. It's been that long since I have done a drum brake job.

addilac -- A little sludge on the bottom of any closed system is normal. I wouldn't worry about the rest of the system.

[BodybyFisher]

adallack, one last tip from me. Don't use petroleum based solvents on parts that will be contacted by brake fluid. The proper solvent (after brake clean sprays of course) is alcohol, either isopropyl or methanol (poison) based. Also do not use any type of oil inside the wheel cylinders, or grease for that matter. Just use brake fluid if you need to lubricate something inside the system.

Sorry for firing up the way-back machine!

Thank you for the tips. Got new cylinders. Will do tomorrow if the weather permits.

, the next problem will be getting the brake tubing out of the wheel cylinders, if you dont have one, buy the correct size flare nut wrench or flarenut claw for your ratchet set

[adallak]

adallack, one last tip from me. Don't use petroleum based solvents on parts that will be contacted by brake fluid. The proper solvent (after brake clean sprays of course) is alcohol, either isopropyl or methanol (poison) based. Also do not use any type of oil inside the wheel cylinders, or grease for that matter. Just use brake fluid if you need to lubricate something inside the system.

Sorry for firing up the way-back machine!

Thank you for the tips. Got new cylinders. Will do tomorrow if the weather permits.

, the next problem will be getting the brake tubing out of the wheel cylinders, if you dont have one, buy the correct size flare nut wrench or flarenut claw for your ratchet set

Yep, rounding the brake nut is a possibility. I should have right tubing wrenches. I believe, the nut is either 3/8" or 7/16". That's how a two hour job turns into something different. BTW, something I really hate about my Fleetwood is that you cannot get the jack out and in the trunk without actually getting into trunk. Must look funny to a bypasser. Getting the full size spare out is another nice workout! LOL

[Cadillac Jim]

The brake hose fittings are probably metric. What looks like 3/8" or 7/16" is likely 10 mm or 11 mm.

If you ever really need to change your tire and drive on the freeway with it, you will be thankful for a real jack that gives you a safe, simple tire change and a full-size tire that gives you worry-free control at speed. OTOH, AAA Plus and a cell phone are always best. The spare is for when that doesn't work, like when the cell phone can't get a connection.