Drum Resurfaced Finish

[Insert Quarter]

No idea on lengths. FWIW - I got Raybestos off RA. Haven't had any troubles yet.
On my truck, the passenger side cable was the worst, the main front cable was sticking as well.
That pretty much fixed it and later I replaced the drivers side cable.

 

[wildwilly]

Doing some research on brake cables: Dorman and Oreilly have pretty good application notes and filters to narrow it down. The front is clear for an Extended cab short bed at 65.74 inches. There are two options for the rear and they are referenced by front rotor diameter. Normally JB5 as 11.9" front rotor and 10" drum. JB6 for the 2500s are 12.5" rotors and 11" drums. My truck has 11.9" front rotors but 11" drums.

Rear Left: 11.6" front rotors (JB5) use 84.64" cable, 12.5" (JB6) front rotors use an 83.93" cable.
Rear Right: 11.6" rotors 96.06" cable, 12.5" rotors 103.15" cable.

I suspect my rear with the larger drums is going to use the JB6 cables. BTW neither code is in my glove box it has J 9 something and J F something if I recall so I do not know exactly what brakes I have except by diameter.

I will attempt to measure the right cable to confirm the 103 inch theory with my larger drums and go with that at the parts store tomorrow. This may give me the best clue as to what to buy. The left cables are so close in length they may not matter, but I will compare at the store as both are in stock.

Anybody else out there have any experience on parts choices for cables? THANKS!

 

[Schurkey]

Normally JB5 as 11.9" front rotor and 10" drum. JB6 for the 2500s are 12.5" rotors and 11" drums. My truck has 11.9" front rotors but 11" drums.

Rear Left: 11.6" front rotors (JB5) use 84.64" cable, 12.5" (JB6) front rotors use an 83.93" cable.
Rear Right: 11.6" rotors 96.06" cable, 12.5" rotors 103.15" cable.

Unless there's model-year differences I don't know about, JB/JD5 and JB/JD6 use the SAME booster, SAME master cylinder, SAME rotors, and SAME calipers. The rotors are listed in the '97 C/K service manual as 11.57" diameter; so 11.6 is close enough.

The JB/JD5 has the shiity 254mm (10") leading/trailing shoe rear drums. The JB/JD6 has the decent 11.15 Duo-Servo rear drums.

JB/JD7 and JB/JD8 use 12.5" rotors and 13" drums, but the drums and shoes are wider --3.5" vs. 2.5" on the '8s, and the '8s with dual rear wheels got thicker rotors.

That leaves JF9 which is only on C3500HD so far as I know. Bendix calipers on 13.86 rotors, Dana rear axle with disc brakes, totally-different from the Delco stuff on the other trucks.

I suspect my rear with the larger drums is going to use the JB6 cables. BTW neither code is in my glove box it has J 9 something and J F something if I recall so I do not know exactly what brakes I have except by diameter.

Unusual. I'd have expected JB6. You seem to have JB6-style rotors, and JB6-style drums.

The earlier trucks went by "JN" rather than JB for vacuum boost, JD for hydroboost. But the number part of the designation was the same except for "1" (No power assist) and "3" which was thin rotors and small pistons in the calipers, and a smaller piston in the master cylinder compared to "5".

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[wildwilly]

Good info. I was going off this thread. https://www.gmt400.com/threads/jb5-jb6-jb7-jb8-size-thread.39647/
I think maybe there was the listing of the 12.5 disk on the JB6. The 12.5 are 8 lug on the parts listings that you would see on a 2500 not a 1500. So that would mean I have the JB6 option? It does have the larger drums and larger diff as it had the tow package option. Here is my service tag. Nothing I have found explains it ... JD9, JF4, JHD, and JL1 are the Js listed? Thanks.

 

[wildwilly]

Just measured the right rear cable. It is 92 inches including the screw to the outside of the drum. There is probably close to 2 inches into the drum so definitely the 96 inch length cable called out for the JB5. The 103 inch cable is for the 12.5 inch rotors as it is called out so that would be JB7 if I am not mistaken ... so my conclusion would be the JB5 and JB6 cables are the same. If anyone has some thoughts let me know, but I am heading to the parts store now and will report back how it goes. I may get them on today yet, but have to be done tomorrow.

 

[wildwilly]

Two trips to the parts store. The part store listing for JB5 did not fit. I must have miss-measured. The cables that worked were listed as a vehicle with the 12.5 inch rotors. I have the larger 11 inch rear drums and the 11.6 inch front rotors. The right side is listed as 103 inches and the left side just under 84 inches. The left rear listed for the JB5 is just over 84 inches, but the sheath is longer, no exposed cable and did not reach to the coupler nor align with the equalizer adjuster.

As far as the surface finish on the drums there has been no issues.

I had not posted as I was waiting to drive it, but I did take them by three shops that listed they turn drums and asked for a second opinion. Two more nationally known names basically said the same. It looks a little more than what they typically do. The sanding is intentional and keeps the shoe from tracking like a record during initial break in. They ran their nail across the drum and id does not hang. I think the pictures posted exaggerate the grooves. The third shop was a local one just offered to smooth them up if you want. The mechanic looked at it and did not say any more than this. He did feel it and just offered to take a bit off. I get it, he was nice, but I was imposing a little bit so maybe he wanted to not give free advice, but I got a little bit more of a feeling they did not really know. Or maybe he does not do this cross hatching and one of the other shops said you do not have to, but some/most do.