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bleeding rear brakes on 69

1877 Views 7 Replies 7 Participants Last post by  BPOS
My car has front disc, rear drum power brakes. I have the following situation in the rear: one wheel cylinder driver side with broken off bleeder valve and the left brake line rusted pretty bad. The brakes work fine, but I'd like to replace the wheel cylinder and the left axle line. I have the axle line nuts loose which took some time with liquid wrench. I didnt loosen them up enough that fluid comes out. Wheel cylinder nuts look a little scary but I will start with the liquid wrench on them next. after I buy a new wheel cylinder and line, I will try to replace the parts but my problem is that Ive never bled brakes before. Ive have searched and found some strange answers without clarity on how to do it, especially concerning the rear wheels. Is there anyone that has the time or know how to explain how to do this job to a novice? I could always go to a shop but I wouldnt learn anything about my car that way and also risk someone butchering it. I was also wondering if I take my left rear line off, would I have to bleed every wheel and the master cylinder?
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First if you need one rear brake line on one side you are not far from needing the other side. Also I would concider the ruber line over the axle, if it is original it should be replaced too. To bleed the brakes, start at the right rear
(its the farthest to the master) have someone push down on the brake pedal lightly untill the pedal goes to the floor or builds a lil preasure, while holding the pedal down losen the r.r. bleeder then tighten it back up. Tell your helper to pump the pedal slowly two or three times ( let the pedal come backall the way to the top each pump)(make sure your helper knows not to let up on the pedal even a little untill you close the bleeder it will suck air back in) then hold the pedal down and you open the bleeder again, repeat this three or four times check the master for brake fluid and do the same for the left rear. Never pump the pedal with the drums off. keep switching back (left to right) untill absolutly no air come out. You may have to do this whole thing several times (never letting the master fluid get lower than half full. If you pedal is low after your test drive note if its beter after you pump the pedal to a stop or if its always low. If always low its probably the rear shoe adjustment, if pedal gets harder it probably has some air still. ( good time to check emergency cables too) Hope that helps
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Aren't the rear brakes self adjusting? By backing up the car and appling the brake? But bleed the brakes as Blue SS stated. Unless you have access to a vacuum pump then you can suck the brake fluid through the lines. I just replaced all my lines on my 69. Right Stuff has the lines you need, I would replace both while your at it. And both wheel cylinders also. Have fun, it was my first rear drum brake job that I've done also. Learning is fun!
If you attach some clear tubing to the bleeder valve and run it into a jar with extra break fluid in it, you will be able to see the air bubbles much better. I got my rear brake lines from Right Stuff. They were pre-bent and fit perfect.

Bleeding the brakes ain't that bad - it will be easier in my opinion than the other work you have ahead of you with the wheel cyliders etc.

If you don't have a helper - I've used this bleeder tank from Motive Products a few times and it works like a champ - available through Jegs or Summit for around $70 last time I checked - it's a one man operation.

If you do go this route, I would suggest using a different clamp set up as pictured vs the j-hook chain set-up that comes with the kit. I have found that you get a much better seal on the master cylinder.


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blue, tgiff, daral and joe, thanks much for all the info to help me fix my brakes up with some needed parts. Ill order from rightstuff ...looks like a great place for brake/fuel parts.
Keep in mind, don't pump the pedal with the lid off the master cylinder. It will splash brake fluid all over the place, and brake fluid eats paint in a matter of seconds. I use a plastic soda bottle to make it easier. Drill a hole in the lid slightly smaller than the tube (clear is best) you connect to the bleeder screw. Push the tube through the lid far enough to reach the bottom of the bottle. The reason for this is, if the person pumping the pedal lets the pedal up while you have the screw open, it will suck fluid instead of air (or mostly fluid). I keep a short piece of coat hanger wrapped around the neck of the bottle with a hook bent on the end so you can hang the bottle. This frees up one hand and keeps you from tipping over the bottle. Also you have to keep the lid on the bottle a little loose to let air out otherwise as the bottle fills with fluid, it will become pressurized, and when you pull the tube off the bleeder nipple, it will shoot fluid out! Don't forget if you let the master run dry, you will have to start all over again. By the way, no matter how clean it looks, never reuse brake fluid. It's not worth it. As for the vacuum bleeders, I have one, and have used it, but because air will leak around the bleeder screw went you loosen it, it never seems to get the last bit of air out like pumping the pedal, or a pressure bleeder. The pressure bleeder probably does the best job, but they cost more money than a soda bottle, and every time I take one off the master cylinder when I'm done, I get brake fluid all over the place, and as I said, brake fluid eats paint, QUICKLY! Brakes are a serious thing (duh!) so ask lots of questions if you are not sure. The last thing we need is one less Camaro lover in the world!
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The pressure bleeder probably does the best job, but they cost more money than a soda bottle, and every time I take one off the master cylinder when I'm done, I get brake fluid all over the place, and as I said, brake fluid eats paint, QUICKLY!
I have the Motive bleeder - it's an awesome tool. There are a couple of very common sense precautions to assure a leak/spill free job. When you hook up the adapter to the master cylinder, make your connections, and then pump up the bleeder WITHOUT any brake fluid in it. Pump it up to 15 PSI and let it sit for a few minutes. Watch the gauge, and if it stays at 15, you know you have a good seal at the master. Also a good time to check your flare fittings for leaks, as the system is under pressure. Once you're happy the pressure is stable, you can add the brake fluid and start bleeding the brakes.:

To avoid a spill due to an overfull MC when you're done (10 minutes later), after your final corner, just tilt the pressure cannister so that the tube is out of the fluid and just drawing air. Bleed that final corner for a few seconds, and close the bleeder. Slowly unscrew the lid to the cannister to relieve pressure, remove the adapter and you're done.:hurray:
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