Can't get brakes to bleed (78 Chevy K10)

I rebuilt the front end on my truck (new ball joints, tie rods, u- joints, etc.) including the calipers and rotors along with wheel cylinders on the back about 8 foot of new brake line new rear rubber brake hose and a new master cylinder. Now, the peddle is very, very soft.

I believe the problem is only with the front. If I take the front brake line off the MC and plug it (leaving only the back brake line attached to the MC) the peddle is very hard. However, with the front line attached the peddle goes right to the floor.

I replaced the bleeder screws on the calipers just in case that was the problem but it didn't help. I have went through about 3 gallons of brake fluid trying to get the fronts bleed. I don't see any leaks anywhere. Any idea where the air could be getting in through? What would you suggest I check next?

Thanks in advance.

Reply to
ngpost1
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Check if the calipers are switched side to side.

Reply to
Steve Austin

What method of bleeding are you performing? Are you getting a steady stream of solid fluid at all 4 corners or are there still bubble present? Did you let the master cylinder go dry and not bleed it leveled out so trapped air can be expelled? Are the rear brake shoes adjusted out properly? Internal leak in the master cylinder?

Halfway thru the second quart of fluid and no pedal is when you need to back track and find the problem.

Reply to
aarcuda69062

Three things come to mind.

First as mentioned, are the calipers on the correct sides so the bleeders are at the top?

Second is a dry MC. If the MC went dry, it likely needs a bench bleed to get the air out of it. This can be almost impossible on some to do while in the vehicle. The MC must be level and on some, you must push the plunger in farther than the brake pedal can push it so the MC needs to be on the bench.

Third is a the lockout pin on the combination/proportioning valve that is used to get the air out of it.

On some combo valves, there is a rubber boot on one end covering a pin. This pin must be held from moving to get the air out. Some push out, some pull in. I use a helper with 'channel lock' pliers or vise grips to hold it or a hose clamp holding a penny over the pin.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail > I rebuilt the front end on my truck (new ball joints, tie rods, u-
Reply to
Mike Romain

When I had this problem on my race car, I found a pinhole leak on one of the hard lines that was preventing me from getting all the air out.

It sounds like you're doing the right thing, but I suggest taking a "step back" and starting over - assume the whole system has to be bled, check for leaks everywhere, make sure you're getting a good solid stream of fluid from each wheel before moving on.

Ray

Reply to
news

Thanks for all the help.

I had the calipers on the wrong sides. I didn't know you could install them on the wrong side. Once I switched them I was able to bleed them in about 30 seconds.

Thanks again.

Reply to
ngpost1

Just FYI, there is also a right and left on the rear brake adjusters. If you get them mixed, the emergency brake will fast go slack and the pedal height will fast drop down.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06
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Reply to
Mike Romain

In addition to what's been said, it is sometimes useful to fill the master cylinder, leave the top off or loose, and open a bleeder and let it sit for awhile. Eventually, (usually), fluid will come through, and some of the air will make its way through.

Dave

Reply to
spamTHISbrp

stuff happens. :)

FWIW, I learned to always do one side of the car at a time for brakes. It prevents mixing parts up, and it gives you a handy reference for when you're wondering how this spring or that clip goes on.

Ray

Reply to
ray

Good idea, but if he was putting on rebuild calipers the same mistake could be made.

Just remember, bleeder will be on TOP (air rises!)...

--Ken

Reply to
dye

ah... but if you did one side at a time and had two rebuilt calipers, you'd notice that one way would be "right" and the other would be "upside down"

Ray

Reply to
ray

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