In a Quest for USA made Parts

010752

Well-known member
Joined
Mar 24, 2008
Messages
941
Location
S Florida
This is what you can get, casting flaw. :crap:

MasterFlaw.jpg
 
But you had to cut it in half to see, if it was chinese you could have seen it was sh!t on the outside :D
 
But you had to cut it in half to see, if it was chinese you could have seen it was sh!t on the outside :D

"Made in" doesn't seem to mean much these days. You should check out some of the recently made Moog cutaways, from their good stuff.

It just so happens that this little flaw is right where the primary vs secondary seal lip lands, so for the first few mm of travel, the rear piston is pushing fluid into the front reservoir, not much but doesn't do the seal any good either.
Brakes were really good on this car too.:crap:
 
Try to make a complaint via the phone,...last time i found out they charged something like 1 € per minute. Unbelievable. Just take your business elsewhere, easiest solution.
 
Try to make a complaint via the phone,...last time i found out they charged something like 1 € per minute. Unbelievable. Just take your business elsewhere, easiest solution.

Came on the car when I got it. Guessing about 3 years old.
Just an aftermarket casting, not a Delco.


The machine work in that bore looks awful.

It's difficult to show in pics with this camera, but on the far right you can see a decent hatch hone pattern and near the cut I made (can't see it in the pics).

The interesting part is that the worm tracks that look like a poor finish are corrosion from air pockets.
The bore is good near where the power seal is at rest, in each of the front and rear sections. The further forward (tilted up when installed), the wider the corrosion (air gap gets).

I can just barely feel it with my fingernail, and the brakes were decent, but I'm sure the master was at the end of it's life.
I just cut it open to see why these vette brakes can be troublesome and see if any improvements are possible.

Here is another pic that might show it a little better.

Pitting1.jpg
 
On the booster thread, before tossing the towel and going HB, I had changed the m/cyl to a truck unit, larger bore, it was helpful in that less pedal travel, but I had to do more effort.....so that is what was on the car when the HB was installed, I went aluminum aftermarket stock size m/cyl to get some pedal travel back....Did the same thing with the motor home, HB install and a super largest dump truck m/cyl......so it now stops....

:gurney::evil::drink:
 
On the booster thread, before tossing the towel and going HB, I had changed the m/cyl to a truck unit, larger bore, it was helpful in that less pedal travel, but I had to do more effort.....so that is what was on the car when the HB was installed, I went aluminum aftermarket stock size m/cyl to get some pedal travel back....Did the same thing with the motor home, HB install and a super largest dump truck m/cyl......so it now stops....

:gurney::evil::drink:

Did You use the 1-1/4 or 1-5/16"?
The 1-1/4" measures tight into the booster.

Did you reverse the ports, All these truck masters have the front at the rear port of the master.

Did you take out the residual valve?
 
On the booster thread, before tossing the towel and going HB, I had changed the m/cyl to a truck unit, larger bore, it was helpful in that less pedal travel, but I had to do more effort.....so that is what was on the car when the HB was installed, I went aluminum aftermarket stock size m/cyl to get some pedal travel back....Did the same thing with the motor home, HB install and a super largest dump truck m/cyl......so it now stops....

:gurney::evil::drink:

Did You use the 1-1/4 or 1-5/16"?
The 1-1/4" measures tight into the booster.

Did you reverse the ports, All these truck masters have the front at the rear port of the master.

Did you take out the residual valve?

OK, I said truck m/cyl....I dunno which 'truck' all I know is there was no residual valve and as I recall it was a 1.125" diameter....maybe 1.25 but I don't think so......I do have a 1 5/16 on the motor home....

I had to very carefully measure and cut the output shaft from the stock longer adjustable length to fit the 'new' shallow divot hole on the m/cyl.....

according to my calipers, it was dead on, and acted like it...see the piston move soon as pedal moved...no delays...I was really careful not to mess THAT up....I remember going through all the spec sheets with the part guy, and finding what I wanted on the shelf....so nothing outta the ordinary....:drink:
 
On the booster thread, before tossing the towel and going HB, I had changed the m/cyl to a truck unit, larger bore, it was helpful in that less pedal travel, but I had to do more effort.....so that is what was on the car when the HB was installed, I went aluminum aftermarket stock size m/cyl to get some pedal travel back....Did the same thing with the motor home, HB install and a super largest dump truck m/cyl......so it now stops....

:gurney::evil::drink:

Did You use the 1-1/4 or 1-5/16"?
The 1-1/4" measures tight into the booster.

Did you reverse the ports, All these truck masters have the front at the rear port of the master.

Did you take out the residual valve?

if you look at an older Chevy Power book in the Corvette chassis section it tells you the origin of the 1-1/4" truck master
 
[
if you look at an older Chevy Power book in the Corvette chassis section it tells you the origin of the 1-1/4" truck master

Power book says to use a 74 or 75 3/4 up master.
I installed a 1-1/4" from a 76 3/4ton Chevy, but didn't have to slot the mount holes like the Power Book said. Lucky once in a while I guess.
Pulled the cones and no residual valve. Made new lines to the combo valve so I could run the fronts to the master rear.
Quite a bit better than the oem, brakes start at about 1" of pedal depression.
Pedal still not as firm as the 4 wheel disc setup on my wife's Caravan, it's a couple hundred pounds heavier than the vette.

Still thinking that moving to the manual hole will give me what I want, but it's a chore to unbolt the stop lite switch from the pedal and fab a new one, not much room under there.
 
Top