Check Your Brake Caliper for Binding

[Roadtreker357]

The electronic caliper jaws are cut out about 1.5" in. So, rust on periphery didn't interfere with the measurement. Measuring in four locations, squeezing the jaws as mentioned, I got the same reading, 1.490".
According to the service manual the new rotor is 1.496" and the minimum refinished thickness is 1.457". It appears there is plenty of thickness and no variation in thickness,

There is minor surface rust on the disc, due to not using it since January. Also some slight circular lines where the pads rub. See photo attached. Will need to check the runout after I get a gauge.

To reuse this rotor with new Hawk pads, do I need to sand the rotor surface? If so, to what degree? What type/grit sandpaper?

[Roadtreker357]

I have gone beyond the point of no return. The boots have been removed. Have to get a 'pick' to remove the bushing at the bottom of the hole. Any suggestion for the best tool to grab and pull the bushing? the pick used in the video had an angle on the tip. BTW, the bushing does not look swollen, but I will replace it anyway. Maybe I never put the wrong lube on the Roadtrek pins, just the cars.

After seeing all your problems reinserting a new boot, it looks like this might be worth a try. Use tape to wrap around the rubber boot to collapse it. then use a 11/16" deep socket to put over the rubber and onto the metal flange. appears to be a good fit.

[peteco]

I used a long screw to thread into the bushing, just enough to grab it but not too much to expand it excessively.

[Roadtreker357]

Originally Posted by peteco

I used a long screw to thread into the bushing, just enough to grab it but not too much to expand it excessively.

I wish I had thought of using a screw myself. Thanks Pete. Put a rope on the hook to pull with. removed both bushings in short order

[booster]

Originally Posted by Roadtreker357

I wish I had thought of using a screw myself. Thanks Pete. Put a rope on the hook to pull with. removed both bushings in short order

Interesting you got it to work, I tried it and they were so soft they just tore apart without moving. I even loosened the side of the bushing with a screwdriver and got on it with real long nose needle nose pliers, and tore.



I didn't have a heavy pick with that short of a bend on the end to get through the bushing, so I wound up using two dental picks to be able to pull hard enough with more tearing.

[booster]

Originally Posted by Roadtreker357

I have gone beyond the point of no return. The boots have been removed. Have to get a 'pick' to remove the bushing at the bottom of the hole. Any suggestion for the best tool to grab and pull the bushing? the pick used in the video had an angle on the tip. BTW, the bushing does not look swollen, but I will replace it anyway. Maybe I never put the wrong lube on the Roadtrek pins, just the cars.

After seeing all your problems reinserting a new boot, it looks like this might be worth a try. Use tape to wrap around the rubber boot to collapse it. then use a 11/16" deep socket to put over the rubber and onto the metal flange. appears to be a good fit.

The socket thing will be dependent to a large degree on how much lead in they have on the bolt entry side. Some mine had more chamfer than the flange of the bushing was wide, so would have bent the flange. I did have a spark plug socket that had been ground flat on the end and it worked much better, but as I mentioned earlier, I stopped early with socked and used a 1/4" punch to go around and around and focus on the tight spots.


That rotor looks relatively new, as there doesn't appear to be any step on the inside of the diameter from past turning. I use a 60 or 80 grit Scotchbrite pad on an angle die grinder to rough it up. you want fairly rough and random direction scratches. You have to be sure to get all of the old brake pad residue off so can take a lot of sanding. It is a pain to do by hand and is much better if you use a sanding block with the coarse paper on it so you can see what is high or low or residue. Also watch for small blue/black spots showing up, which are hard spots in the cast iron and can cause thumping. I just give them a tiny hit with a grinding stone to put them below the surface. Not all rotors are prone to it, but some can get really bad with them.

[Roadtreker357]

I just ordered the Hawk pads, from Walmart of all places. HB322Y.717, Hawk and Amazon say this is the correct pad for the Chevy 3500 (they don't mention front or back). Walmart says it is the wrong pad. We will see.

FYI. Amazon had delivery May 3. Walmart was $10 less per pair and with home deliver Wednesday. Also, Hawk has a $10 rebate until the end of May.

Asking again, do I need to remove surface rust from existing rotor (or otherwise sand/prepare the rotor surface) before Hawk break-in?

[booster]

Originally Posted by Roadtreker357

I just ordered the Hawk pads, from Walmart of all places. HB322Y.717, Hawk and Amazon say this is the correct pad for the Chevy 3500 (they don't mention front or back). Walmart says it is the wrong pad. We will see.

FYI. Amazon had delivery May 3. Walmart was $10 less per pair and with home deliver Wednesday. Also, Hawk has a $10 rebate until the end of May.

Asking again, do I need to remove surface rust from existing rotor (or otherwise sand/prepare the rotor surface) before Hawk break-in?

The front and rear are different pads, the part numbers should be in the other thread you linked earlier IIRC.


I addressed rust earlier on the hub and rotor locating surface, the bracket under the small slides, etc. You don't have get all the rust off entire rotor, just the contact/locating areas and the outside diameter of the braking surface so the pads will go in easily. Knocking off any loose rust on the rest is always a good idea to keep it from getting under the rotor or pads while putting it together.

[Roadtreker357]

Thanks for the clarification on rust, Booster. I guess your earlier comment got lost in my mind.

Next is to remove the other caliper and get it ready. Then wait until April 20 for all the parts to arrive

BTW, I checked my maintenance record and it was these slide pins that were lubed by me, 2 years ago, with the Synthetic Permatex that is advertised for metal to metal only, but elsewhere for pins. Since the bushings were not mushy or swollen, I came out OK. After this project, it will be even better.

[Roadtreker357]

Originally Posted by booster

I highly doubt that the pads are original at 168K miles and still that thick, so they likely have been replaced at least once. The rotors also are unlikely the originals, but would have to look to see if they are identified on them. The pads do seem to show numbers, so that could be checked possibly to find out what they really are.

I am rereading this entire thread and summarizing all the good information this forum has provided. The quote above just caught my eye. All parts are OEM. I bought this RT used in 2008 when it was 9 months old, so I doubt the original owner had brake work done. I have never replaced the rotors or pads. the unused pads are what has kept me from getting better pads. The grease issue was the straw that broke the camels back.

BTW, I down shift a good bit, mainly due to poor brake performance for quick stops and even some stop signs on down slope. This probably contributed to the longevity of the pads and rotors. Last time I looked at the rear pads they looked similar to the front.

[booster]

Originally Posted by Roadtreker357

I am rereading this entire thread and summarizing all the good information this forum has provided. The quote above just caught my eye. All parts are OEM. I bought this RT used in 2008 when it was 9 months old, so I doubt the original owner had brake work done. I have never replaced the rotors or pads. the unused pads are what has kept me from getting better pads. The grease issue was the straw that broke the camels back.

BTW, I down shift a good bit, mainly due to poor brake performance for quick stops and even some stop signs on down slope. This probably contributed to the longevity of the pads and rotors. Last time I looked at the rear pads they looked similar to the front.

That is pretty interesting to me, as those parts look like 20-30K mile parts. The lack of ridge on the OD of the rotors is a sure giveaway. Rears I would say very possible as those tend to last a long time. I have been trying to find, for years, someone who could modify the Hydroboost module to put more braking on the rear as I think it is a simple spring or valve adustment, as the factory would almost certainly have it set up to handle an empty van, so very light braking in the rear. I have not found anyone who even attempted it for an offroad vehicle and GM has made lots of these units. My guess it that you could probably put as much as 50% more braking or more on the rear compared to what it has now, which would certainly help braking.


It makes one wonder if there may be some issue with the front system on your van, perhaps air in the lines or a bad hydroboost module. If there is air in the module itself, you need a analyzer like a Tech2 to cycle the module while you bleed them and pretty much nobody ever does that unless there is a problem. No way to do other than an line bleed at home AFAIK which will not get air out of the module. The very poor braking you describe doesn't really sound like what many others, including us, experienced. The big problem was downhill hot brake juddering, not overall stopping ability in normal driving. Going to the Hawk pads did reduce our pedal effort a bit, but hot a big deal at all, though. Having similar wear front and rear would kind of also support that idea I would guess as we have at least 2 to 1 ration of front wear to rear wear. The OEM ceramics wear well, but your pads look like ours did at 20K miles.

[peteco]

I was shocked at how little wear was on the original front pads when I changed them to the Hawks at 50k miles. I still have the pads: 0.42" of pad. I had poor braking as well. I am easy on brakes and downshift on big inclines. So Roadtreker's experience is similar to mine.

Regarding brake proportioning; it makes sense more rear braking would help on our heavy rear load Roadtreks. Not sure anyone would offer such a system though, due to liability.

Anxious to see how his new brakes work for him.

[Roadtreker357]

I have never had the judder in all the Rocky Mountain driving I have done, pulling a utility trailer with motorcycle. One time in the past year, however, on a level surface I felt a little judder for a short period.

I have changed the brake fluid several times, by myself. Maybe there is some air. I guess I need to get the DW to do the pedal pushing and holding while I do the bleeding to watch the flow through the tubing.

The brakes will stop the vehicle but the pedal effort is more than I am accustomed to. When I get in another vehicle, i generally at first brake way too much until I remember I am not in the RT.

[Roadtreker357]

Originally Posted by peteco

Anxious to see how his new brakes work for him.

I will surely let y'all know. Don't hold your breath, however. Job won't be completed until the end of the month and no trips until virus season is over, Brake pad conditioning is not really a good test, but I might have something to report then.

[peteco]

Originally Posted by Roadtreker357

I have never had the judder in all the Rocky Mountain driving I have done, pulling a utility trailer with motorcycle. One time in the past year, however, on a level surface I felt a little judder for a short period.

I have changed the brake fluid several times, by myself. Maybe there is some air. I guess I need to get the DW to do the pedal pushing and holding while I do the bleeding to watch the flow through the tubing.

The brakes will stop the vehicle but the pedal effort is more than I am accustomed to. When I get in another vehicle, i generally at first brake way too much until I remember I am not in the RT.

I change brake fluid every 2 years. I use a mityvac hand pump vacuum to suck the fluid out the calipers. I use a gallon to thoroughly flush the system. The final step is to do a pedal pump/hold/bleed on all 4 calipers. That final step produces the most solid pedal.

[booster]

Originally Posted by peteco

I was shocked at how little wear was on the original front pads when I changed them to the Hawks at 50k miles. I still have the pads: 0.42" of pad. I had poor braking as well. I am easy on brakes and downshift on big inclines. So Roadtreker's experience is similar to mine.

Regarding brake proportioning; it makes sense more rear braking would help on our heavy rear load Roadtreks. Not sure anyone would offer such a system though, due to liability.

Anxious to see how his new brakes work for him.

Yep, liability is a big deal for sure, and there may also be lawsuit threats from GM or the manufacturer of the systems. Usually, even with those things, the offroad guys are doing it anyway, so kind of odd. You can get an adjustable proportioning valve for nearly any non ABS pressure controlled system, so definitely different.



I think your van is also a 2006? As I mentioned, I didn't see big change in normal braking with the change in pads on our 2007. I wonder if things changed a bit after 2006, as they did do a refresh in 2007 the year. Drive by wire, different steering gear, etc. We are seeing the same front to rear ratio, it appears, on the Hawk pads that we did with OEM, where the fronts looked to be at about 2/3 left and rears looked new when I changed them. I am not a big engine braking person in general, and only really do it if the van will run away in the higher gear and require lots of braking input, so that may make a difference. We did use lower gears on the Smoky Mountain parkway and Skyline drive however, as there were lots of curves to slow down for also. I don't recall downshifting on the Eisenhower when we have gone down it either way. The old axiom of "brakes are cheap, but transmissions are expensive" seems to be imprinted in my driving habits for some reason, and that is fine unless you over heat the brakes and die

[Roadtreker357]

"The old axiom of "brakes are cheap, but transmissions are expensive" seems to be imprinted in my driving habits for some reason, and that is fine unless you over heat the brakes and die "

My saying has always been that I would rather be along the side of the road with a bad transmission, instead of along the side of the road ready to go to the morgue.

[Bud]

My 05/04 Express Van brakes are seemingly happy and have never been touched, Nothing with the brake system, but only 115K miles. Transmission is happy too, but changed the fluid once.

Plenty, more than enough brake pad front and back at 110K miles, not checked since. I sense some $'s will be needed sooner rather than later, maybe 5-10 years from now? OK, maybe I exaggerate a little about the later.

Oh, plenty of western US mountain miles. I downshift a LOT and drive like an old man. I sure have enjoyed brakes though - Porches, Corvettes, motorcycles.......

Bud

[Roadtreker357]

I have been looking at various YouTube videos today to see if I could pick up any more nuggets of good information. In the last video viewed, when pressing the caliper pistons inward he first pinched off the fluid line and cracked open the bleeder. This was done to ensure no fluid backed up through the ABS module. According to this person he has seen this (more than one time) mess up the ABS module so fluid will no longer flow to that caliper when the brakes are applied. He says this is specific to GM and not an issue with other brands.

If you have the stomach for foul language, this is discussed starting at 20:15 and ends about 27:00.

Wondering if any on this forum have seen this happen and if there is any truth to this issue.

https://www.youtube.com/watch?v=IJuYUYtM4OM

[booster]

Originally Posted by Roadtreker357

I have been looking at various YouTube videos today to see if I could pick up any more nuggets of good information. In the last video viewed, when pressing the caliper pistons inward he first pinched off the fluid line and cracked open the bleeder. This was done to ensure no fluid backed up through the ABS module. According to this person he has seen this (more than one time) mess up the ABS module so fluid will no longer flow to that caliper when the brakes are applied. He says this is specific to GM and not an issue with other brands.

If you have the stomach for foul language, this is discussed starting at 20:15 and ends about 27:00.

Wondering if any on this forum have seen this happen and if there is any truth to this issue.

I didn't look at the video, but was this a hydroboost vehicle or vacuum booster?


I have never heard of this issue, but I will try to get a look at the factory service manual and see what it says about it.