Chevy brake update

[booster]

We finally got into some tougher conditions, so were able to get a better test of the Hawk brake upgrade we did a few years ago. Not the Rockies or Pikes Peak, but the Skyline drive, Blue Ridge Parkway, and especially the Smoky Mountain Parkway were pretty good. Intentionally worked them hard a couple of times to the point of being able to smell them, and got no fade or pulsating to that point. Looks like it is a big improvement over the stock parts.

[AK49er]

Good news booster. We lost a caliper in WA state and had it replaced only to have that one freeze up also. Might have to look into Hawk brands soon.

[peteco]

Can you give us the part numbers and source. Thanks.

Pete
2006 RT210P

[booster]

Front rotors HUS8659

Front pads HB322Y.717 The Y is the compound code for the LTS pads

Rear pads HB494Y.670 The Y is the compound code for the LTS pads

These are for our 2007 with the semifloating rear end. They don't make rears for it, but the OEM rotors in the rear seem to be doing just fine

I think there is a very good possibility that most of the gain that is achieved with brake upgrades is from the pads, rather than the rotors, along with a good bedding process when installing them. The Chevy ceramic pads that come with the van are nice and clean on the wheels, but don't do much else very well, I fear.

[peteco]

Thanks for the info. I didn't realize the OEM pads were ceramic. My understanding is that ceramic is not for heavy duty applications.

[peteco]

Just curious. How did you select the Y compound code? I see they have a P code that is supposed to have better stopping power and wear but worse noise and dust. This is according to their catalog.

Pete
2006 RT210P

[booster]

Originally Posted by peteco

Just curious. How did you select the Y compound code? I see they have a P code that is supposed to have better stopping power and wear but worse noise and dust. This is according to their catalog.

Pete
2006 RT210P

Here is a link to the catalog online that describes the parts in a bit more detail. In it they say not recommended on lighter vehicles (one ton and under) on the street, which I confirmed by calling them. What they said was that they were a lot like the very high performance race brakes, that need to be hot to work well (I had race pads in a hotrod once, and I can agree they were scary until you got them hot), so they didn't consider them good on the street except on heavy trucks. Since I haven't used the severe duty ones, I can't confirm that, though.

http://www.hawkperformance.com/sites...ATALOG_WEB.pdf

It is interesting that they only show the P compound available for the front, and the vans already have to much front brake on them IMO. The higher friction material would make it worse.

[peteco]

Thanks for the clarification and for researching it deeper than I probably would or could.

I am thinking I will try just the pads as my rotors seem fine and they are a bigger job to change than just the pads. The pads show little wear (at least 0.20 inch of pad remaining) but I am easy on the brakes. I have 64,000 miles on the vehicle and there is no vibration when braking, it just doesn't slow down like I would like it to do in a hard stop situation.

Pete
2006 RT210P

[peteco]

I just finished upgrading to the Hawk brakes: front rotors and pads, and rear pads. It took a while as I do brake jobs infrequently, so I have to relearn the finer points.

One finding was that the rear caliper pins were almost completely dry. I will add this to my maintenance plan.

Another finding was that all the brake pads were barely worn at 64,000 miles. I attribute this more to GM's design than to my easy driving habits. I think these "hard" pads lead to poor braking performance, which I hope the Hawk pads remedy.

The most difficult part of this job is bleeding the brakes to get a firm brake pedal. I have a Motiv pressure bleeder that works fine but it never quite got all the bubble out after bleeding 3 qts of fluid through the system. The pedal is not as firm as I would like. I have done the pad burnishing procedure that Hawk recommends. I will report my braking results after a few weeks on the road.

I also greased the hubs and will report my experience in the hub thread:

viewtopic.php?f=12&t=2417&p=24265#p24265

Pete
2006 Roadtrek 210 Popular

[booster]

Originally Posted by peteco

I just finished upgrading to the Hawk brakes: front rotors and pads, and rear pads. It took a while as I do brake jobs infrequently, so I have to relearn the finer points.

One finding was that the rear caliper pins were almost completely dry. I will add this to my maintenance plan.

Another finding was that all the brake pads were barely worn at 64,000 miles. I attribute this more to GM's design than to my easy driving habits. I think these "hard" pads lead to poor braking performance, which I hope the Hawk pads remedy.

The most difficult part of this job is bleeding the brakes to get a firm brake pedal. I have a Motiv pressure bleeder that works fine but it never quite got all the bubble out after bleeding 3 qts of fluid through the system. The pedal is not as firm as I would like. I have done the pad burnishing procedure that Hawk recommends. I will report my braking results after a few weeks on the road.

I also greased the hubs and will report my experience in the hub thread:

http://www.classbforum.com/phpBB2/viewt ... 265#p24265

Pete
2006 Roadtrek 210 Popular

I have always thought our brake pedal was a little soft and with a bit more travel than it should be, but it passes all the specs in the service manual, so it just may be a bit different than we are used to.

We did notice that the pedal seemed a bit softer after the brake change, but it also firmed up a bit after more use. It appears that those huge pads need a bunch of use to get fully flattened out to the rotor. After our trip though the mountain parkways, where we worked them very hard, they got a bit better yet.

A couple other things made incremental improvements. A good bleeding the first time we changed the brake fluid (before the brake change) got us a little better, as I got a bit of air out of the rears. I have never had great success with power bleeders, probably just me, because I would get a little air back in around the bleed screws when closing them. I was always by myself so I couldn't leave it pressured up well, and it was a cheap bleeder. I went back to the old pump, hold, open two person routine now and haven't had problems. I think part of it is if you do have any air, the first burst out of the bleeder when you crack it, will squirt differently than if there is not air, so you know when you are done. We didn't run the van when we did the manual way. I always use Dot4 Castrol LMA fluid, but that shouldn't have any effect on feel or travel.

I did change the Hydroboost fluid last year, and that did make a difference in feel and needed force, both for the better. I went with Redline synthetic power steering fluid, but they now recommend their D4 auto trans fluid, which I am going to go to this year. It has a bit higher viscosity at high temp than their ps fluid, and both are much better at high temp than the GM stuff. It is interesting that in cold areas like here in Mn, GM says to go to their thinner ps fluid, which would make it worse (they have some low temp issues with the standard ps fluid). The Redline is much thinner at cold temps, so there should be no issue with it. Even with the Redline ps fluid, I noticed an immediate reduction in pedal effort, as it is probably holding a little more pressure at the relief valve. The power steering pump also got a bit quieter. I would guess the ps fluid is running significantly cooler, also, based on touching the reservoir. From what I have read about Hydroboost, they need regular fluid changes, and should be done at or before the fluid starts to darken, if you want long life. I have no long term experience with them, so can't speak to that.

I think you will find the pedal to firm and raise for a while as the brakes fully seat. The bedding is more a concern with material transfer, but I would bet you still don't have 100% contact, I know I didn't even after about 6K miles (easy ones), so I just started using them harder If you have been bleeding a bunch, you probably have all new fluid so that is good, but you may want to do a quick manual bleed to see if you get any air squirts. Changing the Hydroboost fluid to a good synthetic is a good idea, I think. I really like Redline for gears and gear type pumps, but I am sure there are other good choices also.

By the time you get to 10K it will probably be pretty nice, although the changes are so slow that you may not notice unless you think about it. I still wish ours had a bit higher pedal, but I like the feel and force, which does not change as they heat up like the stock pads did.

[peteco]

Thanks. I drove about 4 hours after bedding the pads and can already tell the brakes are better. Like you, the pedal travels further than I would like but it works.

I had changed the Hydroboost fluid when I removed the steering box to replace the Pitman arm last year. The system is a bit noisier than before. Maybe I should flush and put a higher quality fluid in.

I forgot to mention that as part of the bleeding process I tried to activate the ABS system by putting the vehicle in drive while it was raised. The drive wheel spins while the other wheel does not, and this is supposed to activate the ABS. This was recommended on other sites to pump the old fluid out of the ABS circuitry. I could not hear any ABS system activation so I don't know if it worked or not. One reason to do this was I had replaced the fluid in the summer and it appeared that the fluid had become contaminated.

Anyway, I guess I have the brake system as best as possible, short of taking it to a dealer, and that is a crapshoot on whether they will do it any better than I have. They are supposed to have a system to activate the ABS pump as part of a brake fluid change.

Pete
2006 Roadtrek 210 Popular

[booster]

Originally Posted by peteco

Thanks. I drove about 4 hours after bedding the pads and can already tell the brakes are better. Like you, the pedal travels further than I would like but it works.

I had changed the Hydroboost fluid when I removed the steering box to replace the Pitman arm last year. The system is a bit noisier than before. Maybe I should flush and put a higher quality fluid in.

I forgot to mention that as part of the bleeding process I tried to activate the ABS system by putting the vehicle in drive while it was raised. The drive wheel spins while the other wheel does not, and this is supposed to activate the ABS. This was recommended on other sites to pump the old fluid out of the ABS circuitry. I could not hear any ABS system activation so I don't know if it worked or not. One reason to do this was I had replaced the fluid in the summer and it appeared that the fluid had become contaminated.

Anyway, I guess I have the brake system as best as possible, short of taking it to a dealer, and that is a crapshoot on whether they will do it any better than I have. They are supposed to have a system to activate the ABS pump as part of a brake fluid change.

Pete
2006 Roadtrek 210 Popular

I went through the ABS cycling thing also, and there appears to be almost no way to make it work at home. The only ones I saw that were successful were in the north and took them out on the icy roads to get them to cycle, bleed, repeat. I talked to a half dozen GM dealers about the flush with cycling and they all looked at me like I was nuts, so I just kind of gave up about that part. The only time ours has ever cycled was when the wheel bearing seized.

[tlillard23]

years later, how's everyone like Hawk brakes? I love Hawk brake pads for racing, didn't see these pads were available when i was shopping...

I went with Power Stop Z36 Truck & Tow Brake Kit Part Number K6561-36 . I am unimpressed, cold braking is sketchy and after bed-in it was easy enough to overheat the brakes to the point if felt like they released, or faded to zero braking *I've read elsewhere of people having this problem - might not be the brake pads fault. 07 chevy roadtrek

I use a Chinese tech2 for the abs bleed process. runs the pumps and valves automatically. I think most tuner/obd devices have abs bleed too. pretty sure hptuners has it?

[booster]

Originally Posted by tlillard23

years later, how's everyone like Hawk brakes? I love Hawk brake pads for racing, didn't see these pads were available when i was shopping...

I went with Power Stop Z36 Truck & Tow Brake Kit Part Number K6561-36 . I am unimpressed, cold braking is sketchy and after bed-in it was easy enough to overheat the brakes to the point if felt like they released, or faded to zero braking *I've read elsewhere of people having this problem - might not be the brake pads fault. 07 chevy roadtrek

I use a Chinese tech2 for the abs bleed process. runs the pumps and valves automatically. I think most tuner/obd devices have abs bleed too. pretty sure hptuners has it?

Our Hawk pads have not had any issues at all and perform very well.


I have a Tech2 also but haven't tried it on the van for the ABS bleed to this point. I think it my need some upgrade for the later year but not certain. I have not run across it in the HPtuner program, but haven't looked closed for it either. The HP does not allow you to force sensors and controls like the Tech2 so it may not have the bleed capability.

[peteco]

Amazon has the Hawk front brake pads at a good price now. I bought a couple weeks ago at $99. Now $95. Most other places selling for $138. May be a year or 2 before I need new fronts but stocking up now at this price.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[mkguitar]

I see the price has been bouncing around the past week.


The front seems accepted to be an advantage on the Chevy express, how about the rears, I don't see a part # on the hawk lookup


I've not had problems but pretty sure I'll swap to the hawks ( for the front at least) the next time

[booster]

Originally Posted by mkguitar

I see the price has been bouncing around the past week.


The front seems accepted to be an advantage on the Chevy express, how about the rears, I don't see a part # on the hawk lookup


I've not had problems but pretty sure I'll swap to the hawks ( for the front at least) the next time

IMO, you should always have the front and rear as identical in material as possible to maintain the front to rear balance. Different brands and styles can have very widely varying friction characteristics and heat handling.


The exception would be if you are trying to intentionally change the front to rear bias, then you would possible try different pads end to end.

[mkguitar]

Rear part number/application didn't show for me on Hawk's website.

[booster]

Originally Posted by mkguitar

Rear part number/application didn't show for me on Hawk's website.

I do remember that the PN was hard to find and maybe they have been discontinued.


The part numbers for front and rear are in several of the Chevy brake threads I have started. I will see if I can dig them out.


On edit: Found them.

Front pads HB322Y.717 The Y is the compound code for the LTS pads

Rear pads HB494Y.670 The Y is the compound code for the LTS pads

[mkguitar]

Thanks Booster.