Break Drums

N

NSWCPO72

Member
Hello,
my system
72 sii
345

I recently did the front drum breaks on my 72sii, I ordered new drums (po had some hack jobs on both fronts guess he didn't wanna do it right) and shoes 11x2s when I went to put the drum on it was tight real tight even after adjusting the shoes.
The hub turns but there is significant drag and as stated before getting the drum on was tough / tight.
Question is
is this normal and the shoes will wear to fit? Or is there something wrong?
I ordered the first drum from sss and was told that it was 11x2 for the fronts. I ordered a second new drum from sss which came in last night but I can see that it is not the same as the first drum ordered, looks more like the rears so I know that I will have to return this and get the other which sets me back a week again.
Thanks for the help and advice.
R/
t
 
Just gonna toss out some ideas here...

A) are the front shoes "new" from a parts house or did you have them relined locally? Either way, the actual friction material could be slightly "thicker" as compared to oem spec...that is fairly common.

B) are the front drums new replacements or some used drums that have been reconditioned by turning the friction diameter? Have a local brake shop use a drum micrometer and compare the id of the old and new drums.

C) are you certain the slave(wheel) cylinders are completely retracted an not hanging up? If you did not rebuild 'em, then it's entirely possible the pistons are stuck in their bores (one or both) and not allowing retraction.

D) the oem master cylinder had a nominal 10psi "residual pressure valve" installed in both circuits just in front of the outlet fittings. These valves maintain minimal slave cylinder travel when the return springs pull the shoes off contact with the drum. You May have to pull the fittings out of the master cylinder and verify/clean the valves so they can operate properly. Those are normally a simple one-way "check valve" that looks like a rubber disc.

E) if the friction material on the shoes is slightly oversize, then a brake shop can "arc" the shoes to your new drums using a grinding process.

F) make certain the star adjusters on both sides are completely retracted (take 'em apart and clean lube) and nothing is holding the shoes out. The shoes themselves could be the wrong "pattern" which is very common on "replacement" shoes. They must be identical in every respect to the shoes you took off.

I'd not try and "break in" the new shoes/drums with a significant amount of drag. The superheating will cause the friction material to burnish and glaze, and can also cause drum "warp".
 
nswcpo72 said:
hello,
my system
72 sii
345

I recently did the front drum breaks on my 72sii, I ordered new drums (po had some hack jobs on both fronts guess he didn't wanna do it right) and shoes 11x2s when I went to put the drum on it was tight real tight even after adjusting the shoes.
The hub turns but there is significant drag and as stated before getting the drum on was tough / tight.
Question is
is this normal and the shoes will wear to fit? Or is there something wrong?
I ordered the first drum from sss and was told that it was 11x2 for the fronts. I ordered a second new drum from sss which came in last night but I can see that it is not the same as the first drum ordered, looks more like the rears so I know that I will have to return this and get the other which sets me back a week again.
Thanks for the help and advice.
R/
t
Click to expand...

Since sss supplied the drums I would call them and let them know that the two drums you received are different. One could have been misboxed?? I have seen from the factory that the Scout II's had two different types of front drums - one with fins and one without.
 
Sorry for the late response:
I did contact sss and all is right in the world they are excellent people there.
An update:
I managed to get both new drums on, the left side is still real tight. Yes new shoes and new drums. I did clean / lube the star adjuster and make adjustments. The right drum fit a little tight to but not nearly as much as the left. Guess a little slow wear will be in order. Yes I did bleed and adjust all the breaks / break lines too.
Took her out for a prelim run and test the breaks ect...
I am experiancing some other troubles not break related so if this post needs to get moved I understand.
But first the setup /system
72 sii
345 v8
edelbrock carb (1405) manual choke
new fuel line and fuel filters(of which I will have to fab a bracket for the fuel psi regulator)
new 3gauge cluster for oil psi / temp / volts all hooked up and tested.

1. When driving her and on a slight incline she cuts out or stalls. Is there something I should look at or adjust first?
2. She got real hot(I think) 210-220 range yes I had been idel and was at slow speed, it did cool down a little when drove around the ranch but I wasn't at highway speed either. Is this normal? I recall reading that op temp range was between 180-190. Also now the temp gauge is reading at 140 even when I haven't drove her for 2 days. :icon_eh:
any suggestions
thanks for all your help.
 
Sorry for the late response:
I did contact sss and all is right in the world they are excellent people there.
An update:
I managed to get both new drums on, the left side is still real tight. Yes new shoes and new drums. I did clean / lube the star adjuster and make adjustments. The right drum fit a little tight to but not nearly as much as the left. Guess a little slow wear will be in order. Yes I did bleed and adjust all the breaks / break lines too.
Took her out for a prelim run and test the breaks ect...
I am experiancing some other troubles not break related so if this post needs to get moved I understand.
But first the setup /system
72 sii
345 v8
edelbrock carb (1405) manual choke
new fuel line and fuel filters(of which I will have to fab a bracket for the fuel psi regulator)
new 3gauge cluster for oil psi / temp / volts all hooked up and tested.

1. When driving her and on a slight incline she cuts out or stalls. Is there something I should look at or adjust first?
2. She got real hot(I think) 210-220 range yes I had been idel and was at slow speed, it did cool down a little when drove around the ranch but I wasn't at highway speed either. Is this normal? I recall reading that op temp range was between 180-190. Also now the temp gauge is reading at 140 even when I haven't drove her for 2 days. :icon_eh:
any suggestions
thanks for all your help.
 
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