73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: txchainsawgogi on February 26, 2011, 04:33:36 pm
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any idea what would cause noticeably softer brakes in the course of a week? im not leaking brake fluid... but im sure i could use new pads. its on the to-do list!
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check master cylinder fluid level.
You could have air in the brake lines too, inspect the lines for any signs of wetness signalling a leak. Take rear drums off and check for wetness on shoes.
If drums come off easily, your self adjusters may be bad and not adjusting the rear brakes.
I'd definately try and bleed the brakes.
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it probably is the master cylinder starting to go. its got surface rust all over it, maybe it finally ate its way through.
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i don't think it would rust too much inside where the fluid is. I wouldn't replace the master cylinder w/out checking for leaks and bleeding the lines first.
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i will check the lines but i dont know how to bleed anything bigger than a harley. i get the concept, i just havent done it myself before.
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(http://i1134.photobucket.com/albums/m612/wolfmantough/2011-02-26190518.jpg)
grimy, kind of moist surface rust.
(http://i1134.photobucket.com/albums/m612/wolfmantough/2011-02-26190457.jpg)
you can kind of see it in the picture, but theres a leak coming from where the master cylinder bolts up.
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Yep. Get a new master cylinder.
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And learn how to bleed the Master Cylinder, and brakes cause you'll NEED to do both after the replacement.
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alright so, the M/C bleed method is more or less the same as on a bike i assume, but what sort of tools am i lookin at?
is there a how to on here?
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i think the bleed screws on brake calibers and wheel cylinders in shoes are either a 7/16" or 3/8" so get wrenches/sockets that size...i prefer flare wrenches to protect the screws from rounding off. Start at the furthest wheel from master cylinder and work to closest. Right rear, left rear, right front then left front.
Keep topping off the m/c or you'll be pumping air in again and starting all over again. Bench bleed a new m/c prior to attaching the lines.
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i guess im gonna have to buy a "one man" bleeder kit. i dont have anyone to help me do this haha how sad. should i get a bleeder system or one that pumps fluid into it? i've seen those in use and it looks super easy.
also, is this a p.o.s.? autozone seems to only carry FENCO brand m/c's as a direct replacement for mine.
http://www.autozone.com/autozone/parts/Fenco-Reman-Master-Cylinder-Brake-System/1978-Chevrolet-C10-1-2-ton-P-U-2WD/_/N-imvp7Z8kn47?counter=2&filterByKeyWord=master+cylinder&fromString=search&itemIdentifier=227967_56045_0_3912
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i rigged up a way to use a 2x4 board cut a certain length, and used a bunji cord to keep pressure on the board. The top of the board had a V groove on it so the bunji cord wouldn slip, the board pushed the brake pedal down...worked pretty good.
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You need to "Bench Bleed" The master cylinder.
Just search bench bleed and you'll find this has been discussed several times.
http://forum.73-87chevytrucks.com/smforum/index.php?topic=5127.0
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got it. bench bleed, then bleed each wheel. just pump it until no more air comes out then move to the next wheel.
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When you bleed the brakes, start at the passenger rear, then move to the drivers rear, then the passenger front, then driver front. You want to work your way closer to the master cylinder, starting as far as possible from it.
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Slammed, you mean like this?
i prefer flare wrenches to protect the screws from rounding off. Start at the furthest wheel from master cylinder and work to closest. Right rear, left rear, right front then left front.
;D
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haha. i got it. im gonna pick up the m/c and a lot of fluid tomorrow after work.
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Just like that Sarge!! It was a really long night last night!
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Start now with spraying the bleeders with some pb blaster or similar, and be prepared for lots of swearing if one snaps off. I like to use a 6-pt socket with a ratchet just to break them loose initially.
Sometimes the new m/c will include some hose, fittings, and instructions on bench bleeding.
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so true Grim, I can't tell you how many bleeder screws I snapped off over the years, usually the smaller 3/8" ones on drum wheel cylinders. Good thing wheels cylinders are cheap. The caliper bleeders are usually bigger and I have less problem w/ those.
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AWESOME. a few hours of good brakes and now its leaking again where the master cylinder meets the brake booster.
will using a rubber o-ring or making a cork gasket fix this long term?