3 rear brake caliper bleader screws ?

[entropy454]

In most of the threads and google searches I've done on how to gravity bleed your brakes. It is always mentioned that the rear caliper has two bleeder screws. One on the inside and one on the outside.

The calipers on my car that I replaced had this format. One bleeder screw on the inside up high and one on the outside down low.
On my old calipers, there was also a non-bleeder screw placed in the outside high position.

The new 'rebuilt" calipers I bought from local parts store Had an extra bleeder screw in the outside high position. This is for a total of 3 bleeder screws per rear caliper.

Anyone have an idea why there is a bleeder screw in that position for the rebuilt caliper and how does it effect the order when bleeding?

thanks

 

[redvetracr]

whoever rebuilt your calipers didn`t have plugs....don`t bleed the bottom ones they are there in place of the plugs

 

[6880 Mike]

The brake line attaches to the inside bottom half; outside bottom half should be plugged. Bleeders are at the top of each half.

 

[entropy454]

Thanks, guess I better re-bleed my brakes. Figured I would have to do it a few times anyway

 

[JohnZ]

The calipers on my car that I replaced had this format. One bleeder screw on the inside up high and one on the outside down low.
On my old calipers, there was also a non-bleeder screw placed in the outside high position.

The new 'rebuilt" calipers I bought from local parts store Had an extra bleeder screw in the outside high position. This is for a total of 3 bleeder screws per rear caliper.

Can't imagine how you ever bled the brakes and got the air out with one bleeder down low; they both have to be at the top. Rears have an inner and outer bleeder at the top, none at the bottom.

 

[73shark]

Maybe someone got the right and left inner caliper halves swapped. :confused

 

[jrzvette]

The brake line attaches to the inside bottom half; outside bottom half should be plugged. Bleeders are at the top of each half.

Does it make a difference whether you bleed the inside or outside first?

 

[TimAT]

I like to bleed brakes at a point that's as far from the master cylinder as I can get and then work my way toward it.

 

[jrzvette]

I like to bleed brakes at a point that's as far from the master cylinder as I can get and then work my way toward it.

So using that method it would be:
outside right rear
inside right rear
outside left rear
inside left rear
right front
left front

 

[6880 Mike]

On the rear, inner halves must be bled first; outer halves second.

 

[TimAT]

I agree with Mike-
And I should have expanded my post a little bit-

If you bleed the rear first and don't do anything to the front, assuming the system is dry, the proportioning valve could move to the side with no pressure and lock it out. So you really need to work the RR, then the LF, then the LR, and the RF. Keep the system pretty well balanced as far as bleeding goes so the valve dosen't shift on you. Slow and easy is the key.

I have a Motive Bleeder and it makes the whole thing easy. No worries about pumping the pedal and holding it at the right time. Makes it a one man job. And IMHO, another advantage is that it fills the whole system at the same time, from the top, so no worries about the proportioning valve.

I'm calling it a proportioning valve, but in reality it's just a distribution block with a valve and a switch in it. THe idea is it will shut off whichever end loses pressure and turn on the brake warning light.

 

[JohnZ]

I'm calling it a proportioning valve, but in reality it's just a distribution block with a valve and a switch in it. THe idea is it will shut off whichever end loses pressure and turn on the brake warning light.

Actually, it has no valving function at all, and there's no interconnection inside it between the front and rear systems; both sides of the spool are sealed. When one system fails, pressure on the good side exceeds the pressure on the failed side, which shifts the spool, grounding the switch terminal in the center, turning on the warning light.

The photo below is a later combination valve, but the center section shows how the differential pressure switch operates.