'89 Burb V2500 JB7 Different Pad Options?

[Girth]

So I kinda want to go throw parts at the counter guys at my local Napa. Had my wife call to order parts, tell her I want rotors, wheel studs, bearing seals and brake pads. (Getting ready to yank the hubs, pack bearings, generally look everything over on a "new to us" truck, and install a new master/booster, and replace the worn/grooved stuff up front).

First loop I was thrown.... they asked what size rotor I had? No idea, I was at work. Their site lists one pad set used on "w/ 13" X 2 1/2" Brakes" and the other pad option as "11 5/32" X 2 3/4" but no mention of brake codes. Are the rotors different sizes between the JB5 and JB7 options, or is it a difference in calipers/piston size? RPO code in the glovebox tells me its a JB7, and that's how I ordered the new master/booster. Suppose I might just have to yank a wheel off tomorrow and see what's on there.

Then came the "I wanna throw these heavy parts at them" part of the story. She went to pick up parts today. I was trying not to fall off a ladder, hanging off the side of a helicopter when my phone starts ringing. She sent me a picture. "Is this what you wanted?". It's a picture of a whole rotor/hub assembly. NO.... I did not want their Chinese hubs and bearing races. She told them that, she gave them very specific (because I wrote it down) instructions of what she wanted..... and they ordered whatever they felt like. They tell her "It's all one part. See, the box says brake rotor". I also told her to pick up a socket for the hub nuts. They send her packing with a 36mm 12point?

Only bright side right now is she DID grab both pad options, and the bearing seals. If I can source the right socket for the hub nuts, I can at least scuff up the rotors, pack bearings, and pad slap it, and keep the truck on the road while I figure out the rest of the details.

 

[SquareRoot]

I'm not sure anything is NOT Chinese. Even AC Delco branded parts are Chinesium. Sad

 

[Originalthor]

I will say about brake pads is that the brembo ones leave a brown brake dust on everything.

Napa ones if you get the commercial grade they grab like a mother after a bit and if your just creaping to a light they make noise.

 

[fast 99]

Our shop had issues with NAPA pads, noise, dusting, excess wear, ect. We changed to Carquest those seemed better. Buy realistically most brake complaints are caused by improper installation or abuse. Personally, I have been using ceramic, but many brands aren't heavy duty. Even though Delco may be made in China they are probably better overall.

There are a lot of procedures that can decrease the possibility of brake noise. We have tried them all but that is another subject. Some vehicles are just going to be noisy.

An FYI, brakes always make noise. The trick is to keep it out of the range of human hearing.

 

[Girth]

Still not sure which pads I need. Probably gonna send it all back and source parts elsewhere

 

[Girth]

I'm not sure anything is NOT Chinese. Even AC Delco branded parts are Chinesium. Sad

Basically the reason I wanted to do the work to swap just the rotors, and keep my hubs and bearings if they aren’t worn. We’ll see.

Wife found the socket, thanks to the two old ladies at Oriellys. lol I’ll tear into it tomorrow and see what’s what.

 

[Blue Ox]

If you have 13" drums you have the JB7 brakes and the front pad is a D153. If you have the 11" drums it's a JB6 and uses a D52 pad. Rotors on all the 20 series 8 lug are the same. Everything else, like calipers, master and wheel cylinders is different however.

I've used Performace Friction Carbon Metallic pads and they give excellent life, almost 2X what Semi-mets do with no rotor wear. Naturally, they cost money. For shoes I like the heavy duty/fleet type. What they call it varies by brand, but they're much longer lasting than conventional organic materials.

 

[Girth]

If you have 13" drums you have the JB7 brakes and the front pad is a D153. If you have the 11" drums it's a JB6 and uses a D52 pad. Rotors on all the 20 series 8 lug are the same. Everything else, like calipers, master and wheel cylinders is different however.

I've used Performace Friction Carbon Metallic pads and they give excellent life, almost 2X what Semi-mets do with no rotor wear. Naturally, they cost money. For shoes I like the heavy duty/fleet type. What they call it varies by brand, but they're much longer lasting than conventional organic materials.

The D153 number was helpful. It's listed on NAPA's site and on their parts, but in the fine print. Until I mentioned it, the counter guy had no idea what I needed. Kept going on about 10in and 12in diameter rotors, and I kept telling him the rotors should be the same, I just need to make sure I've got the right pads (and now calipers). Their website lists rotors with dimensions of 11 and 13in, but I'm pretty sure that's in reference to the rear drums. (Quick tape across the backing plate says mine are 13in, as the backing plate is well over 13in) Actual rotor measures at 12.5

Whatever was on the truck, wasn't fitting right, as evidenced by the inner pads (just the inners for some reason?) hanging off the edge of the rotor.

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One pad had a rock stuck in it, grooved the rotor pretty deep, and the outer edges are stepped from the pad overlapping. Bearing seals were shot, and the inner bearings had been taking water. Nice brown grease, full of water, and their inner races had some pitting. Outer bearings look good, but they're Japanese, the inners are Timkens. One caliper's dust seal was shredded, with part of it trapped between the pad and piston? Odd. Bleed screws were one ugga dugga from rounding off. Soo.... about to go slap all new stuff on and hope it fits. Using the NAPA hubs/rotors, new Chinese bearings , Napa calipers (I gotta go polish the seat for the banjo bolt. WHY can't they do that anymore on reman calipers???), and some semi-metallic pads. The "easy route", as I have other stuff to fix and the wife will be cranky if she can't drive it.

No cores due except for the calipers, so I will measure the old rotors later and see if I can have them turned. Source some good bearings and repack my old hubs for later down the road.

Glad I'm in there today though. Wife took it to Les Schwab for an alignment yesterday, since I knew I didn't do a great job measuring when I replaced the tie rod. lol Almost payed dearly for my laziness. Tire monkeys didn't tighten the clamps on the adjuster sleeve for the relay rod/drag link? Like didn't even snug them up. I just happened to lean in and rest my hand on the sleeve.... and realize it turned freely. I KNOW it was torqued, because I did it last week.

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[rusted nuts]

I buy cheapest the pads I can, Pads are cheaper than rotors

 

[Blue Ox]

Watch the piston diameter on the calipers. I don't have the book in front of me now, but the JB7 uses a metric size, I want to say 80mm. The hoses and fittings on the larger caliper are different too. Just be sure you don't give up the bigger cores for a set of car calipers.

I'm sure you'll get it sorted, but the biggest issue with any of these things is not knowing who did what to it before. Keep the faith.

 

[Girth]

Watch the piston diameter on the calipers. I don't have the book in front of me now, but the JB7 uses a metric size, I want to say 80mm. The hoses and fittings on the larger caliper are different too. Just be sure you don't give up the bigger cores for a set of car calipers.

80mm sounds right, just remembering something I read earlier. The pistons are BIG.... but yeah, I'll go measure. Looks to be an all-nighter.... after dinner. I took the "day off" work for this. lol At least the weather is nice.

 

[Girth]

About 90% done, 90% to go..... since I still gotta rip the rears apart, go through them, and bypass that weight sensing valve. That's gonna be another day though.

Good info for others.....Basically everything Derek/Blue Ox said. If you have 13" drums you have the JB7 brakes and the front pad is a D153. If you have the 11" drums it's a JB6 and uses a D52 pad.

Pay attention to your piston sizes too. The reman'd calipers I got from Napa (jury is still out on if they'll leak, find out tomorrow), the pistons measured a tad over 3in, which jives with 80mm....ish. Who knows with remanufactured stuff, but the calipers that WERE on the truck, their pistons measured more like 2.75in, roughly. I'm guessing they had the pads for the JB7 loaded in the JB6 calipers, and that explains why the inner pad overlapped the edge of the rotor? Either way, REAL obvious difference in piston sizes.

Awesome "weekend" for me. I think the counter guys at Napa cringe when I come in now. First they (the store manager actually) gave me pinion bearings, rather than inner wheel bearings. So that was one run into town. They thought they'd given me the wrong rotor/hub assemblies, so they sent a driver out to the coast to grab two more (along with one caliper that they didn't have), and he delivered it to my doorstep...... only to find out they were what I already had. At least I had both calipers now. After I got everything torqued up, I went to put the locking hubs back in..... and one would NOT slide into the wheel hub. Yanked that hubs assy off, and still no-go. The slines in the new hub were JUST off. Gave it a little motivation with a screwdriver handle, it stuck and raised metal on the locking hub. NOPE...not doing that, for sure machined wrong. It dropped into the other no problem...... so another trip back into town, and fortunately they still had the rotor/hubs that guy had run to the coast for, so swap one defective part for a less defective part. (Chinese hubs.... I was afraid of this) Got everything bolted back up, got the new calipers on, went to hookup the brake lines, and then another bit of Derek's wisdom slapped me.

The previous owners, in order to get those smaller calipers to work (remember.... Derek mentioned brake lines and the location for the banjo bolt), they swapped the brake lines (longer/braided, in my case) side to side. That was another fun surprise. Got those swapped back around, and just dropped the leaky master cylinder out before dinner. Now to go see about yanking the vac booster, bench bleeding the new master, and hopefully getting the new stuff stabbed in. Bleeding everything can wait until tomorrow.... when I have light, to find the leaks I'm guessing will be there.

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[Girth]

Well.... great success, so far? I hate torquing axle nuts. Always wonder in the back of my mind if they're too tight/too loose. lol Did the 50lbs while turning, several times, then backed off 1/6-1/4 turn, lined up the washer.... sure. Hope those China bearings hold up.

Gravity bled all four corners to flush out the whole system, clamped the pin down on the distribution valve, and had the wife pump and hold for me. Took her out, did a few cycles of hard braking to bed the new pads. Stopped to check for leaks... nothing so far. Wet spots inside the wheels though, but not in line with the caliper really. Thinking grease or preservative oil from the new hubs/rotors. They DID get hot, from me hammering on them, but after the easy drive home, didn't seem overly warm. Told the wife to keep an eye on it, grab the hub/lug nuts, etc, to make sure they're not getting too hot. She's cooked a rotor before.... she knows what it smells like. lol

 

[bucket]

Quite a few years ago, I tried to put JB7 calipers in place of my JB5 calipers. I was under the impression it was a direct swap. I bolted one on and found that the banjo bolt hole was 7/16" thread, not 10mm thread like my originals. So I went back and looked at the listing and the listing said the JB7 calipers were supposed to be 10mm. I had the parts store send me another pair, figuring the first ones were in the wrong reman batch. Nope... they were 7/16" as well. So I gave up on it and had the parts store send me a pair of JB5's so I could just bolt them on and go home for the day. I never looked into it again because honestly, the brakes were plenty powerful enough as is (rears are the wide 13's from a 1-ton though).

So did the JB7 calipers retain the 7/16" thread through the rest of the squarebody years? Far as I knew, most all GM products across the board went to metric banjo bolts around '79.

 

[Girth]

Quite a few years ago, I tried to put JB7 calipers in place of my JB5 calipers. I was under the impression it was a direct swap. I bolted one on and found that the banjo bolt hole was 7/16" thread, not 10mm thread like my originals. So I went back and looked at the listing and the listing said the JB7 calipers were supposed to be 10mm. I had the parts store send me another pair, figuring the first ones were in the wrong reman batch. Nope... they were 7/16" as well. So I gave up on it and had the parts store send me a pair of JB5's so I could just bolt them on and go home for the day. I never looked into it again because honestly, the brakes were plenty powerful enough as is (rears are the wide 13's from a 1-ton though).

So did the JB7 calipers retain the 7/16" thread through the rest of the squarebody years? Far as I knew, most all GM products across the board went to metric banjo bolts around '79.

I have NO idea. Every set of reman'd calipers I've gotten in recent years came with their own bolt for the banjo fitting, as did these. I never even considered the thread size, just put it together. Seeing the different location/orientation of the banjo fitting on the two different calipers though..... yeah, I can see how it's not just a "bolt on and go" thing.

I DID have some calipers on my CJ5, that I had to reuse the old banjo bolts. The ones that came with the calipers wouldn't fit through the lines? Threads matched, but the shank dimension was off? It's a Jeep thing.... stuff never just works.