Getting frustrated with brakes.....

[FLYNAVY30]

My brakes have felt like crap since I bought my 72 C20 back in May. At first, I replaced all 4 bleeder screws since they were all clogged with rust. Then I bled the entire system with 3 full bottles of fresh brake fluid with a Motive power bleeder. That helped a little bit, but they still didnt feel like they should so I replaced the master cylinder, booster, and both front calipers and pads. I bought new drums, shoes, and cylinders for the rears, but havent gotten to them yet. I then bled the system thoroughly again, and it was good for a couple of weeks. I went out to take the truck over to Home Depot this morning, and it feels like mush again. The pedal has to be all the way to the limit of its downward travel to get any stopping force, and thats minimal at best.

Anyone have any ideas? Im completely lost. Its not a complicated system. The only thing I can think of is that Im somehow sucking air into the system, but if that was happening, there would be a leak someplace, and as far as I can tell, I dont have any leaks....the master cylinder is still full......

[Bigdav160]

I bought new drums, shoes, and cylinders for the rears, but havent gotten to them yet.

The rear brakes are critical to pedal feel and pedal travel. With your symptoms, I would have started there.

[FLYNAVY30]

ahhh, ok.....guess thats this afternoons project. I had no idea, but that being said, this is my first car with drums so Im learning as I go.

[GuyO]

Fly, I have had similar problems. Once you adjust the rears, pull the hoses down as far as possible and re-bleed. It will force any air left trapped out of your new bleeders. Remember to start bleeding at left rear, not passenger side. Also, there is an adjustment nut on the push rod from the peddle to the master cylinder. Take up all the free travel until you get the feel you want. Good luck and keep us posted. Guy

[FLYNAVY30]

Awesome, thanks for the help!
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[jorgensensc]

I definitely second the rear brakes! They are very important in older cars. If they are adjusted the car will feel like it won't stop worth a darn.
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[LockDoc]

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This is for the drum portion of the brakes only…

One thing I found on mine is when you put everything back together and adjust the brake shoes you can’t just adjust them out until they start rubbing and quit. You have to adjust them out as far as they will go and you cannot turn the wheel at all. This centers the whole assembly in the drum. (I even tap around the drum as I tighten them to help them center themselves) Then you back them off until the wheel just turns, and stop. If you only adjust them out until they start rubbing and quit, the first time you press on the brake pedal the brake shoe assemblies will center themselves and you will have too much clearance between the shoes and the brake drum.

I know it is a pain in the butt to try and hold the self adjusters off of the adjuster wheel while you back them off, but this is the only way I could get my shoes adjusted correctly.

LockDoc

[FLYNAVY30]

so the rear brake cylinders were shot....pissing fluid everywhere....unfortunately, in the process of removing, or attempting to remove the cylinder, I rounded off the 3/8 nut on the hard brake line.....crap!

[vectorit]

At least you discovered why your brakes have been weak.

This would be a good opportunity to get a new rubber hose for the rear axle, since it is probably petrified and a safety hazard.

[faribran]

i know its a bit late... but i learned like u .... i now use "line wrenches" where i can on brakes.. good luck, it will all work out..........

[FLYNAVY30]

Ahhhh yes..."line wrenches"....I discovered those on trip #3 of 4 to the parts store. Once all was said and done, replaced 2 rear cylinders, adjusted the tensioners on both sides and all is well....it actually feels like I have brakes! Thanks for all the help guys!