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.

wrote:
> 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.
>
Check if the calipers are switched side to side.

In article
om>,
wrote:

> 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.

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.

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 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 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

wrote:
> 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.
>

wrote:
> 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.
>

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

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.

ngpost1 wrote:
> 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.
>

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 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

On Jul 18, 8:07 am, wrote:
> 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.


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

ngpost1 wrote:
> 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.
>

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

In article <2UVni.131139$xq1.78328@pd7urf1no>,
ray > wrote:
>ngpost1 wrote:
>> 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.
>>
>
>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.

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

--
Ken R. Dye an optimist is a guy |
Chicago, Illinois that has never had |
www.geocities.com/MotorCity/Track/8746 much experience |
dye1146 at sbcglobal dot net archy |