Useless Information

[gooffeyguy]

Finally got the front finished and then began tackling the rear. I'm very weak and doing just one side is exhausting these days even though it only takes a few minutes.

Lifted the RR caliper off the bracket and saw that the rubber around the piston has a hole in it but is not leaking. Piston compressed smoothly. Outside pad depth on that side just under 7mm after 34K miles. The LR caliper piston had some initial resistance and then compressed smoothly. Pads on this side are just over 7mm for the outside ones.

Could not get the rear rotors off to inspect the parking brake shoes so we decided to skip it, didn't want to spend anymore money or down time on a new puller set. So we got it all back together and went to bleed the brakes. No joy! The RR bleeder was stripped and even the line wrench was slipping off of it. Vise grips didn't work with the caliper on the car.

So I just decided to let her sit for another couple of weeks and buy new rear calipers, pads, parking brake shoes and maybe the parking brake cables and actuator. Not happy with another un-planned expense when we should be sitting on the beach in Daytona. Anyhow, it's the Lord's money and the truck needs to be fixed right to be up for any task we ask of it.

Not liking having her down during hurricane season either. Hmm, might pull that caliper to get the bleeder replaced until the new ones show up. Thoughts?

The rear brake calipers are twice as expensive as the front as GM wants a core charge of $40 per side; none required for the front.

Pics or it didn't happen, lol

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[swathdiver]

Pics or it didn't happen, lol

Well, the RR caliper is drying in the oven but I did take photos of some of the front brake parts.

The OE calipers were Australian, from a company called PBR Brakes USA. The new replacement Calipers and Rotors are Akebono. The new OE hoses are Flexitech.

The front and rear pistons are the same. Checking with Rene to see if the seals and gaskets are as well. When the RR caliper comes out of the oven I'll look for makers marks.

 

[gooffeyguy]

I have PBR branded calipers on my mustangs

 

[swathdiver]

I have PBR branded calipers on my mustangs

No complaints, they lasted 150K miles and stopped 13K pounds like it was nothing.

 

[DRKN57]

No complaints, they lasted 150K miles and stopped 13K pounds like it was nothing.

That’s good use!


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[swathdiver]

Still sitting in the driveway on stands waiting for a part. Should arrive today and then I'll rebuild the last rear caliper and put everything back together over the weekend and get the brakes bled, hopefully they work!

GM does not list any parts to rebuild the rear aluminum calipers. But the parts to rebuild the fronts are exactly the same. So I have rebuilt one and waiting on a new bleeder screw (fine thread) to rebuild the other and get this thing back on the road.

Quite busy with home, kids, other car repairs and work so my time spent on here will be limited for a while. Haven't forgotten about you Okeechobee boys, I'll ring you all up soon when my truck has its wheels on again!

 

[Tonyrodz]

Still sitting in the driveway on stands waiting for a part. Should arrive today and then I'll rebuild the last rear caliper and put everything back together over the weekend and get the brakes bled, hopefully they work!

GM does not list any parts to rebuild the rear aluminum calipers. But the parts to rebuild the fronts are exactly the same. So I have rebuilt one and waiting on a new bleeder screw (fine thread) to rebuild the other and get this thing back on the road.

Quite busy with home, kids, other car repairs and work so my time spent on here will be limited for a while. Haven't forgotten about you Okeechobee boys, I'll ring you all up soon when my truck has its wheels on again!

Take it nice n slow James. Just pace yourself buddy. We're not as young as we used to be lol.

 

[swathdiver]

Take it nice n slow James. Just pace yourself buddy. We're not as young as we used to be lol.

Tell me about it Tony! Saturday wiped me out and the girls did most of the work! They changed the oil in the other two cars, a hub in the Montana and helped me finish up the truck's brakes.

Finished burnishing the brakes just after midnight last night. Took the family to dinner tonight and all seems well with the brakes. During the draining out of the old fluid and refilling with new, the ABS and manual bleed processes, we went through 5 quarts of brake fluid! Truck stops as before, pedal feels the same, pressure is still in the mid 800s but only takes in the 60s to slow the truck.

I'll come back in a few days or weeks with part numbers and torque specs like was done for the fronts for those who come along after us. Wife is now chomping at the bit for a Yukon Denali! One daughter should have enough money saved to buy a 6.2 NHT Sierra by December or January. These are hard to come by, especially in SLE trim, so it may take a few months to fine the right one. It's gotta have the trailer brake controller too! Same with the Denali!

 

[swathdiver]

Oh, that's the current supplier for GM OE rotors. Don't recall maker's marks on the ones from last year but will check again before using them as weights.

 

[swathdiver]

I'll come back in a few days or weeks with part numbers and torque specs like was done for the fronts for those who come along after us.

For anyone coming along later on and needs some part numbers:

Brake Caliper, Rear, Left = 84191288
Brake Caliper, Rear, Right = 84191287

I did not buy these new calipers but am providing the numbers for reference.

The pistons come 1 to a box, the seal and boot kit will service two pistons. The bleeders for the rear aluminum calipers use a fine thread whose part number is provided below.

Brake Caliper, Piston = 15125962
Brake Caliper, Seal and Boot Kit = 23276875 or 179-2262
Brake Caliper, Rear, Bleeder Screw = 88967108

These are GM Original Equipment numbers. Many thanks to Rene for confirming these numbers and providing the GM pricing for comparison. @915_Tahoe

The brake caliper bolts are 13mm and the slide pins take a 20mm wrench. The brake caliper bracket bolts have 18mm heads. The caliper bracket is supposed to have some loc-tite on it and torqued to 122 FT LBS, while the caliper bolts get torqued to 28 FT LBS. When torquing these down, you have to hold the slide pin with the 20mm wrench, but DO NOT let the wrench touch the caliper while tightening or torquing as vibration may ensue while breaking. I do not understand why, that's just what the manual says. The Brake Hose to Caliper Bolts get torqued to 30 FT LBS and has an 11mm head.

 

[gooffeyguy]

Speaking of brakes...

When I replaced the rear brakes on the 2001 last week, I noticed when getting pads there was eith single piston or dual piston calipers. I have dual on the 2001 SLT

I looked at the 2012 rear brakes and they're only single piston. Looking online for rear brake pads there's no dual piston option, so I take it that these didn't come with the option of dual piston rear brakes.

I wonder why the gmt800s did but not the newer models?

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[Tonyrodz]

Speaking of brakes...

When I replaced the rear brakes on the 2001 last week, I noticed when getting pads there was eith single piston or dual piston calipers. I have dual on the 2001 SLT

I looked at the 2012 rear brakes and they're only single piston. Looking online for rear brake pads there's no dual piston option, so I take it that these didn't come with the option of dual piston rear brakes.

I wonder why the gmt800s did but not the newer models?

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Maybe since the gmt900's have bigger front brakes, GM thought dual rear pistons were overkill?

 

[gooffeyguy]

Maybe since the gmt900's have bigger front brakes, GM thought dual rear pistons were overkill?

Possibly. I do know that my 2001 goes through rear pads quicker than the front pads. I have to change them out twice as often than the fronts.
Maybe GM figured out that they weren't needed in the rear.

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[swathdiver]

Speaking of brakes...

When I replaced the rear brakes on the 2001 last week, I noticed when getting pads there was eith single piston or dual piston calipers. I have dual on the 2001 SLT

I looked at the 2012 rear brakes and they're only single piston. Looking online for rear brake pads there's no dual piston option, so I take it that these didn't come with the option of dual piston rear brakes.

I wonder why the gmt800s did but not the newer models?

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Maybe since the gmt900's have bigger front brakes, GM thought dual rear pistons were overkill?

Possibly. I do know that my 2001 goes through rear pads quicker than the front pads. I have to change them out twice as often than the fronts.
Maybe GM figured out that they weren't needed in the rear.

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AFAIK the 800s had twin pistons in the rear and the 900s have single. My rears are aluminum. I saw aluminum front calipers, mine are cast iron. Funny how free enterprise works, the rear hoses are 4 to 5 times the cost of the fronts and are half the size and complexity. Mine are still in excellent condition.

I think you're right Tony. I suspect that my rear pads were original when replaced around 118K. Fronts last a long time too though; with good calipers!

 

[gooffeyguy]

AFAIK the 800s had twin pistons in the rear and the 900s have single. My rears are aluminum. I saw aluminum front calipers, mine are cast iron. Funny how free enterprise works, the rear hoses are 4 to 5 times the cost of the fronts and are half the size and complexity. Mine are still in excellent condition.

I think you're right Tony. I suspect that my rear pads were original when replaced around 118K. Fronts last a long time too though; with good calipers!

I bought my 2001 from my father-in-law in 2007 with 65k on it. As far as I know it still had original brakes (he was original owner). In 2009 I had to put rear brakes on it. In 2016 it needed all new brakes and I replaced everything, calipers, pads, rotors. Last week it needed rear brakes.

So it seems the dual piston rears wore twice as fast as the front, in my case anyway, which is usually the other way around because the front has more weight.

 

[swathdiver]

I bought my 2001 from my father-in-law in 2007 with 65k on it. As far as I know it still had original brakes (he was original owner). In 2009 I had to put rear brakes on it. In 2016 it needed all new brakes and I replaced everything, calipers, pads, rotors. Last week it needed rear brakes.

So it seems the dual piston rears wore twice as fast as the front, in my case anyway, which is usually the other way around because the front has more weight.

Hope mine last as long for the next go-round! Maybe they were hanging up a little? Mine were ok, but one side hung up a little while pressing it back in with a C-Clamp. Was not noticeable in action.

We drove it to the beach to watch the storm roll in and they felt great, just like before.

 

[cfmistry]

It’s definitely unusually that the rears brakes wear so much faster than the fronts. I wonder if anyone has changed the bias to a more conventional 70:30 and seen any improvement in braking?

 

[swathdiver]

It’s definitely unusually that the rears brakes wear so much faster than the fronts. I wonder if anyone has changed the bias to a more conventional 70:30 and seen any improvement in braking?

Maybe his calipers were dragging a little?

 

[gooffeyguy]

Maybe his calipers were dragging a little?

for the past 13 years and 2 different sets of calipers?

 

[swathdiver]

for the past 13 years and 2 different sets of calipers?

No, not likely with 2 different sets. I'd like to run some mileage numbers with mine since doing the brakes but things are quite busy at the moment and for the foreseeable future.