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The flare nut of the break line screws into the cylinder. if you have a flare nut wrench that fits that would be best. A regular wrench would be adequate as well. once you disconnect the line be careful not to get an contaminants in it. the wheel cylinder should bolt wright off the black plate. As for brake fluid, open the reservoir and fill it to the brim before starting this project. You will lose some fluid! Be sure the fluid level does not go below the minimum fill line. If it does you will lose the prime of the master cylinder and will have bleed the whole system. If you keep the level adequate you will only have to bleed the back brake lines. A bottle of brake fluid is an adequate supply; you will need only a few ounces. Once you reinstall the cylinder and brake shoes….DO NOT test the brake lines for leaks until you put the drum back on. Bleed with the drum on as well. You can always take it off to inspect the cylinder seals. Engaging the breaks without the drum on will cause the cylinder to over extend and separate, leaving you with a blown seal and a mess. Hope this helps. BE SAFE
Awesome post by gaseousmercury (love the username by the way!). Great comments and suggestions.
If you have time and are feeling up to it, I would also crack open and bleed the front brakes too (after the read brakes are complete). Again, this is not necessary for what is currently at hand. However, I have found that routine bleeding of all the brake lines accomplishes a couple things. It helps in that is prevents the bleeder valve from seizing in place. Newer brake fluid is also introduced into the entire system. Over time older brake fluid picks up moisture, which can rust the line from the inside out. Good luck and keep us posted.
The brake line SHOULD just unscrew from the back of the cylinder however there are times where the line will also want to twist with it, if this is the case then unmount the cylinder from the backing plate and unscrew IT from the line instead of trying to unscrew the line. I often crip the rubber brake line when doing this type of work to help keep too much fluid from bleeding out as it makes for shorter bleeding when your done. I would normally only bleed the wheels you are working on but you could also bleed out the fronts to make sure you have new brake fluid all around which is not a bad thing. Lastly make sure you really need the cylinders as you don’t need to replace them if they aren’t leaking.
@Eric – I LOVE that tip about disconnecting the wheel cylinder and unscrewing that from the brake
@ eric yeah that might work but i changed the wheel cylinder on a cavalier and i had to remove the entire back plate to get the wheel cylinder out
Something else to take into consideration, manufacturers have gone from from a front/rear split to a right front/left rear split on many fwd vehicles. Obviously this would mean a front left/right rear system as well. This has been added to make sure you have at least one working front brake because the front brakes are reponsible for the majority of your braking power. This would mean if you opened say, the front right bleeder, you should bleed the left rear as well. I don’t know if this applies to your specific vehicle, but it’s something to look into.
I would bleed the brakes at all wheels. This will make sure all the air is out of the lines and you can also replace the fluid while doing this. Just don’t let the master cylinder go dry other wise you will have to start the bleeding process all over again. Also make sure you don’t set the parking brake or step on the brakes with the drums off other wise you will squirt hydraulic fluid all over the place. And after you replace your wheel cylinder and re-install your brake shoes, make sure you check the parking brake cable and re-adjust it accordingly otherwise your regular braking won’t be as effective.
I broke off a bleeder screw last month, and so I replaced the rear (drum) wheel cyclinder on my 98 dodge ram — presumably it’s similar to what you are about to do. I did a video of the experience and put it on youtube. Search “broken bleeder screw repair” on youtube, or just my name. Twisting the brake line off the wheel cylinder was easy in my case, but not always.
Regarding stuck bleeder screws, there is a little tool that is advertised as helping to loosen stuck bleeder screws. It’s here
http://www.babcotools.ca/s.nl/it.A/id.34208/.f
I guess the metal device fits over the screw and you tap on the metal using a hammer or air hammer and the screw is shocked loose. Does anybody have experience with this device?
If you feel the bleeder screw may break, you could use a MAP torch, heat the bleeder screw until its red hot then use ice cold water to help break it free due to the quenching effect.
Its a tip i noted down from an old timer.
Quoted From dreamer2355:
If you feel the bleeder screw may break, you could use a MAP torch, heat the bleeder screw until its red hot then use ice cold water to help break it free due to the quenching effect.
Its a tip i noted down from an old timer.
This is a bad idea on many levels as you never heat hydralic lines filled with fluid for starters because of the dangers of fluid under pressure that could damage you are the system. Second if you get it that hot then you run the risk of melting rubber seals which would also be bad in addition to ruining the fluid from too much heat. If the brake line is stuck follow my suggestion above and you will be fine but never heat a brake line to get it loose. Sorry dreamer2355 I don’t mean to step on your toes but what you suggest creates a serious safety concern.
@Eric – each to there own. Maybe my explanation was a little unclear but i wont try to elaborate anymore. Doesn’t the different type of brake fluid (D.O.T 3,4 and 5) have different boiling points anyhow with D.O.T 3 brake fluid having a dry boiling point
Challenge him. Have you ever seen on the outside of a strut where it says “Do Not Heat”? The reason for this is the same as what I suggest in my comment and that it’s never a good idea to heat a fluid in a confined space. As to your brake fluid ratings it’s heat that breaks the fluid down and part of the reason you should replace the fluid every so often as the more worn out the fluid the lowever the boiling point, your method would shorten the life of the fluid. Given that there is a perfectly viable solution that does not require heat I’m not sure why you would use heat and run the risk.
@Eric – well i appreciate your insight and i value it greatly. Thanks for another lesson S:)
Quoted From spelunkerd:
Regarding stuck bleeder screws, there is a little tool that is advertised as helping to loosen stuck bleeder screws. It’s here
http://www.babcotools.ca/s.nl/it.A/id.34208/.f
I guess the metal device fits over the screw and you tap on the metal using a hammer or air hammer and the screw is shocked loose. Does anybody have experience with this device?
I’d love to see how that thing works.
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