Technical disc brake swap issue..still got a soft pedal

big thanks for your detailed and very informative reply .hoppefully i will have time this weekend and will look at these blots/pin

 

As 31 Vicky said, the floating calipers push the inner pad into the rotor and as a result it pulls the outer into the rotor, if the caliper is not free to slide then it could result in the pedal feeling spongy. Something looks off about how it’s all assembled


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Is that camber issue corrected?

Last I read here is when the rear port is plugged the pedal is firm. Is that still correct?

If so that could be a rear adjustment or a lack of residual pressure valve. The new master should have one built in but who knows. All drum brakes need to have that residual pressure to keep the wheel cylinder cups sealed and air from entering the wheel cylinders.

 

if santa reads this he may send him the answer in place of his 2 front teeth.or a pair of calipers.31 as an aside we used those aluminum spacers on our race brakes with 3/8'' rotors and used the metric calipers.that round one must be recent.

 

I hesitate to stick my nose in here but this is information that could be pertinent. The bottom bracket bolt has a lot of thread showing which got me to wondering if there should have been a spacer in there. I’ve provided links and pics of similar kit
https://www.performanceonline.com/blog/2009/04/55-64-chevy-fullsize-car-sm-caliper-stock-spindle-disc-brake-

 

Something looks mis-aligned in the photos. The caliper is not square to the rotor. Go over the instructions and see what may be wrong. One of the lower bolts has more exposed threads than the other. May be a good place to start.

 

just before intalling the disc brake kit
i swap the old coil spring for new one
the old one were cut and sag badly
i cut the new coil little by little to find the right height , i was so focus with the wheel and fender height ...i may didnt see or look at the camber before....and may as someone else stated here before may be i should check the ball joint.
at one point if i remember i even check with a magnetic angle to the rotor and then resintalled one drum and checked again ,it was similar . ( all with the car on stand without moving it )
may be i never noticed it before ....before this brake disc problem...

 

I have it the same way...yes a bolt is longer one mine...but i know there kit that require sometime to cut them out .

 

i even saw this video on you tube
look like the same kit than mine

 

thanks for your good eyes . i dont reply enough to your post sorry but believe me i read them . i think you right the problem must around that for sure .

 

So far last test i was able to do today
With the clampon it. It is as far as it can go . it didnt move much

 

Watch that video again.
Pay close attention to what he’s saying at about 25 seconds about stock or dropped spindles and left right brackets.
Look at the pins sticking out of the caliper At 2:39

If you changed ride height via springs your camber WILL change due to unequal length control arms

 

About the25 seconds about stock or dropped spindles and left right brackets.
Do you think that should also apply for lowered coil spring only as well? Because i have stock spindle

 

Am I the only one that has noticed that both sides were assembled differently in that video? Look at the anchor pin spacer location from side to side, one is between the spindle and caliper mount and one is between the bolt head and caliper mount. I don't think I would put too much stock in that video. As far as the negative camber issue is goes, doesn't that usually happen when you raise the front ride height? Wouldn't lowering the ride height with shorter springs increase positive camber? To me, it looks like the caliper mounts need about 3\8 of an inch more offset to get everything where it belongs, and also, in the video, there seems to be an excessive amount of drag on the rotors, especially for having fully retracted calipers. I'm thinking poor geometry at best. Now for the pedal feel, have you tried removing the power booster and running manual? I have heard alot of negatives about the small diameter boosters not having enough assist and actually making it harder to stop than manual brakes but have never had any experience with them either. Just my thoughts...

 

He definitely has negative camber, something that happens when lowered because of short long arm suspension


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No I don't like the caliper brackets that use the metric calipers, cheap and not many threads for the caliper bolts. Maybe I'm looking at it wrong but something sure looks off in those pics.

 

I agree with neg. camber. But to have so much with so little drop, I think I'd be checking the 58 year old control arm bushing's and ball joints. In my feeble mind, you'd have to remove the springs completely to get that kind of neg. camber from lowering. And even then, I seriously doubt there would be that much. JMO.

 

I can explain this to you but I can’t understand it for you.

From the video 2:39 where the pins at least look to be right. Yellow circle
The stack up of parts,
spindle (blue)
Bracket (green)
Spacer (yellow)
Bolt. Red

Videos pic shows bracket offset in board

Here’s Vincent nova pic.

Try swapping that spacer around to the other side of that bracket so the bracket is on the spindle.

 

I know this not Vincentnova's car; but I really wonder how someone could even get it together like this without realizing something was out of whack. Must have taken some cranking to get the caliper bracket flexed to fit.

 

!!!!!!! Surely one is incorrect !!!!!

 

Agreed it looks as if the bracket needs to move inboard but isn't the fact that the bracket is sandwiched lower down between the spindle boss and the steering arm going to mean that the bracket isn't going anywhere with that spacer removed? It's as if there's more Z required on the bracket. Backing the caliper pins off two or three turns (just for a test) would presumably prove the point by freeing up some slide room. Still interested in seeing how much inward caliper slide there is with the outer pad removed.

Chris

 

Still waiting to see if caliper pin bushings are missing.

 

Exactly,,
In the video there’s 2 different parts arrangements.
The passenger side “looks” right but parts stacked up different than Vince
The drivers looks wrong, and is stacked up just like vince’s.

 

Sure would be interesting to watch the brakes; while somebody stood on and released the pedal a few times; still seems to me something is out of line, bent, or ???.

Spacer is supposed to between the bracket and spindle for '59-'64. At least it was on the kits we installed. If you think about it; there is no need for a spacer under the head of the bolt (unless the bolt was too long for the blind hole).

Those appear to be the "fat" aftermarket caliper pins, no bushings, the O-rings in the caliper ride on directly on the pin.

 

Probably wrong, but if the upper spacer was removed, that would allow the bracket to move inboard amd the caliper to move outboard (with brake pedal pressure) then the caliper pin would look to be in a more normal position.
Edit- I guess the piston would have to be retracted to center things up. Glad I don’t have anything here with GM brakes or I would be working on it ! I
give up. More help needed from OP.

 

Correct

 

I cant bolt the braket without the spacer...or if i do it will bend the braket

 

Ok, thank you for trying !

 

Move that spacer down here
You obviously need a spacer.

And try mocking it up again.

Something is wrong,
It could be the parts supplied,
It could be what you actually have isn’t what you think it is,
It could be the simple arrangement of the parts.

Be nice if a Hamb member could look at with you.