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Old 03-03-2010, 07:55 PM   #1
GG1
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Need Brake help please!!!

So my front calipers on my 68 swb 3/4ton have been sticking for a few weeks now, finally saved some money to replace them and the pads. that being said, Ive always had a good firm pedal..meaning never needed to pump the brakes. after replacing the calipers and one bad front hose I chose to have my friend who has a tire shop flush and bleed them. got the truck back and the pedal almost goes to the floor unless i pump them three or four times when i want to stop. took it back and got talked into a new master cylinder...witch it did not need!! so still have spongy brakes and have to pump them when i need to get her stopped. So my brakes were better before the new stuff and labor, flush and fluid. So what do ya think my next step should be???....oh and yes they are vacuum assist boosted.
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Old 03-03-2010, 08:02 PM   #2
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Re: Need Brake help please!!!

I'd bleed it all again including the master cylinder.
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Old 03-03-2010, 08:20 PM   #3
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Re: Need Brake help please!!!

bleed them twice so far....is it normal to have to bleed them more than that? i guess what ever it takes! Thank you for the reply.
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Old 03-03-2010, 08:24 PM   #4
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Re: Need Brake help please!!!

The first thing they teach you in mechanic's school is how to bleed brakes.

I got into a knock down drag out fight one day with two of my best friends over it. Basically it involves stepping down easy on the brake pedal while someone on the other end opens the bleeder and then closes it before you lift up on the pedal. You start on the end the furthest from the master cylinder - the right rear, and then to the left rear and then to the right front and then the left front.

When it is all bled - what you have is what you have.

With you being there and me being here, there is no way for me to diagnose what they did wrong or how mixing and matching components would do to your set up. There is always a chance that the other hoses are bad and are expanding when you step on the pedal or that the pistons in the calipers are a different size then the old ones - I just can't say for sure without looking at it.

But if you were mechanically inclined, you would have done this work yourself and then the only person to blame would be you - right.

The way I remember it, if you pushed on the brake pedal with the caliper off the vehicle, the piston would come out. The factory pistons were steel with a chrome finish and usually pitted and rusted and would stick on the rubber seal that went around the piston.

The kits we put in were a ceramic piston and new seals. Were several times cheaper then a brand new caliper. A lot of those parts interchanged on the 3/4 ton from about 1968 to 1980. They all had the same spindles and upper and lower control arms - I know that for sure.
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Old 03-03-2010, 08:25 PM   #5
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Re: Need Brake help please!!!

You might have to bleed the new master cylinder if that didn't get done. Good luck with it.
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Old 03-03-2010, 08:25 PM   #6
michael bustamante
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Re: Need Brake help please!!!

did you bleed all four brake lines and bench bleed the new master cylinder, also did you replace the washers on the new line you replaced? nice truck by the way, my next ones definatly going to be a 4wd
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Old 03-03-2010, 08:31 PM   #7
Monte Carlo Man
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Re: Need Brake help please!!!

If you had no one to step on the pedal for you, you could buy a couple of those one man bleeders- but it is usually cheaper if you just con a neighbor kid into doing it or one of your children or your wife or girlfriend.

I sometimes use a old piece of neoprene hose and a soda pop bottle to catch the old fluid. Never reuse the old fluid.

As far as the comment about not needing the master cylinder - if it got dirt into it and it tore the seals ( O rings) out, it might look just fine on the outside, yet be defective on the inside. Some mechanic's do not loosen up the bleeders before they push the pistons back in on the calipers and usually when the dirt gets back washed into the system - it tears the o rings inside of the master cylinder out anyways.

So I wouldn't necessarily bad mouth someone that was just trying to help you out. I have made lot's of mistakes in the 40 + years that I have been working on cars. Then again, how many 5 year old's do you know that could change a tire on a 1965 Bel Air by themselves.
My daddy gave me heck for putting the lug nuts on backwards.

The spare tire weighed more then I did and I took it out of the trunk by myself, jacked the car up by myself, took all the lug nuts off by myself and put the flat tire back in the trunk by myself.

Last edited by Monte Carlo Man; 03-03-2010 at 08:33 PM.
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Old 03-03-2010, 08:36 PM   #8
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Re: Need Brake help please!!!

I am mechanically inclined, and usually do this all my self but i work over 60 to 70 hours a week currently so its just tough to find the uninterrupted time. ill keep chiseling away at it until its the best it can be. Sucks that its my daily driver.
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Old 03-03-2010, 08:45 PM   #9
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Re: Need Brake help please!!!

Defiantly don't intend to bad mouth the folks who help!! Very greatful, but mostly frustrated.
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Old 03-04-2010, 12:08 AM   #10
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Re: Need Brake help please!!!

Check the line that was replaced to make sure it is tight. I had the same problem. No matter how many times I bled the brakes they were spongy. Turned out when I replaced the master cylinders I was about a quarter turn short of it being tight enough on the right side. Kept sucking air in but not leaking out. Quarter turn later it was fixed.
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Old 03-04-2010, 12:22 AM   #11
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Re: Need Brake help please!!!

I'll echo everyone elses answer- bleed and bleed again. Start with the psgr side rear brake and work your way closer to the master cylinder. Also, check and make sure your back brakes are adjusted properly. If they aren't, that can cause your pedal to go near the floor before engaging the brakes.
Good luck!
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