Brake Problem - RT 05C210P

[Floorman]

80 grit sounds doable. I'll probably cut up some used 80 grit screens and use solid block pad and do it by hand. They only offered one semi metallic that I saw for the '02 Chevy RT. There were three different choices however for the ceramic. I once put a aftermarket super stop pad on the Silverado that ate the rotor. A good friend at the time, a retired Chevy mechanic just shook his head and said "You didn't call me. AC Delco from now on" Thanks for your help and advice.

[peteco]

Originally Posted by booster

A note to all of this that is probably worth stating.


As mentioned, the transfer layer of pad material is critical to stop pulsing.


To get the transfer layer in place, you need bare metal rotors that are either new or sanded to remove all old material on them. You also need new or sanded pads so they will bite will with fresh material showing.


You also need to do the recommended break in procedure, which is usually a series of progressively faster hard stops without coming to a complete stop. When you can just start to smell hot brakes is a good indicator of being done, I have found. Once done don't stop until the brakes are cooled back down or they will imprint. Same is true at the bottom of a mountain road, so the brake temp check stations they have sometime are not really good idea to stop everybody and risk imprinting the brakes.


We had a member here recently that had juddering, even with good pads, that started well into the life of the pads. He was able to fix the problem simply by sanding the rotors and pads and doing a break in procedure. It is suspected that lots of very light braking and sitting may have contributed to transfer layer not being cleaned and refreshed by the pads during harder stops.

I am the member Booster is referring to. I made a new post describing what I did to stop the juddering, along with a few other brake related items.

https://www.classbforum.com/forums/f...tml#post141432

[Crackerjack]

My concern, with my 2007 GM 3500 chassis is simply the "feel" of the brake pedal. Stops are very smooth and controlled - but the brake pedal always feels like I could keep on pushing it to the floor. I have never locked the brakes up to prove I could do so - and I therefore have never sensed that point where I felt the brakes were getting ready to lock. I'm so accustomed to controlled braking that I have a certain timidity with respect to braking hard. My vehicle's GCVR is 12,400 lbs. and her scale weight is 8,400 lbs. in travel mode. With only 70,000 miles on the odometer this is, otherwise, perhaps the best driving vehicle I have ever owned - including my 2003 GMC 3500 diesel dually crew cab 4wd long bed, as well as several other motorhomes and late model cars. Any comments on the vacuum boosted brake system???

[JohnnyFry]

Yes, the pedal feel different. This is largely due to the fact that the brake booster is powered by the power steering pump instead of the more common vacuum booster.

[booster]

Long pedal travel in the Chevies has been brought up several times on this forum.


Bottom line is that they pretty much all have that "too much travel" feel to them, and we really haven't found a cure that would not increase pedal effort by quite a bit.


I have checked our travel and it is right at what the factory service manual says it should be.

[Crackerjack]

Wow! I've never heard of the booster being powered by the power steering pump. Thanks for the information - and for letting me know I'm not alone with respect to the pedal "feel."

[booster]

Originally Posted by Crackerjack

Wow! I've never heard of the booster being powered by the power steering pump. Thanks for the information - and for letting me know I'm not alone with respect to the pedal "feel."

It is called Hydroboost and is powered by the power steering pump instead of engine vacuum.

[Crackerjack]

I mentioned my 2003 GMC 3500 diesel above. Supposingly it should have had the hydraulic booster also - but the brake "feel" was entirely different from my current 3500 van chassis.

[Sensfan]

Originally Posted by booster

There are a lot of discussions on this forum about this topic so a search for them might help out.
Bottom line is that the issue has been tracked down to the use of ceramic pads by GM in the heavy vans. They are not a very good choice for heavy vehicles in general. It has to do with the material transfer to the rotor to give a surface that heats evenly to prevent distortion at high temps, but no need to understand that completely.
We have seen good results from several combos of pads and rotors. The most important is to get top end semi metallic light truck brake pads. Personally, I like the Hawk Performance ones, which we and several others on this forum use. Others have used Raybestos, Bendix, and other good brands. They are often called police, ambulance, super duty, extreme duty, or other terms and will be considerably more expensive the the lowest price semi metallic pads.


The latest information would indicate that the rotor selection is not as critical as once thought, with even OEM GM rotors working well. Any high end, not drilled or slotted, will work well with good pads.
Of course, any combo can be made to fail if you get them hot enough so you need to drive to protect them by downshifing and not riding the pedal on steep declines, but with a good combo you will not get juddering pulsations and just start lose braking power once they get even hotter.
Keeping the brake fluid clean, and preferably Dot4, will keep the fluid from boiling at too low a point. If the fluid boils, the braking goes away nearly completely and that is not where you want to be on a steep downhill.
The brake juddering is a relatively easy, although not real inexpensive, fix based on what we have seen in results from actual users on this and the Yahoo forums.

Non- Class B question please.
After 21,000 miles, my 2017 Volvo front brake pads are getting close to the end of their life-cycle, with 3-5 % left). The brakes have always worked well with no vibration.
Could metal pads provide more braking longevity than the OEM ceramic pads?

BTW .. you are 100% correct. When I started driving hills “manually" as a common practice about 7 years ago; the brake juddering problem on my 2012 RT Ranger disappeared and did not return. The original brakes now have more than 90,000 miles/130,000 kms.

[booster]

Originally Posted by Sensfan

Non- Class B question please.
After 21,000 miles, my 2017 Volvo front brake pads are getting close to the end of their life-cycle, with 3-5 % left). The brakes have always worked well with no vibration.
Could metal pads provide more braking longevity than the OEM ceramic pads?

BTW .. you are 100% correct. When I started driving hills “manually" as a common practice about 7 years ago; the brake juddering problem on my 2012 RT Ranger disappeared and did not return. The original brakes now have more than 90,000 miles/130,000 kms.

Probably not, as ceramic are pretty much known for long life and semi metallic for good stopping power and heat handling.


I was actually quite surprised when I decided to test a set of Hawk High Performance Ceramic pads in my 5000# Buick Roadmaster wagon to replace the semi metallics that were always in it, and I had replaced with very good ones recently. I just wanted to get rid of the dust if possible after I got a nice set of wheels for it. The feel and stopping power of them was very close to semi metallic to the point most would probably never know the difference. Per Hawk about all you give up with them from semi metallic is about 300 degrees of high limit temp and that is not an issue on the Buick like it is in a our van. I don't know how well they will wear, but the semi metallic looked to be a 30-40K mile life based on current wear.

[TX-Trek]

Ditto on training oneself to use manual control on the auto trans for declines. We've had about 4 days of mountain driving and I'm happy with the severe duty semi-metallic pads on the van. But that is combined with using the engine to keep downhill control.

Incidentally I typically install a magnafine filter on the low pressure return side of power steering systems and have done so on the hydroboost return side line in the van.

[Floorman]

Didn't take the new to me '02C190P on the 2600 mile road trip to Colorado from Bishop as I had not had time to get in a good shakedown cruise after recent improvements to the entire front end including brakes. I took instead the 2010 Chevy 2500 HD and it got a work out going up and down multiple 12,000 foot passes. The 2010 has the 6.0 engine and the 6 speed trans with push button lock on any of the 6 speeds. It was perfect to control speed going down the grades. If I had been aware of the difference between the 4 and 6 speed transmissions, I think I would have opted to look for and purchase a 2010 RT. I totally agree that speed control with the power train going off these high passes is vital to preserve the brakes for when you have to stop and I have hope that I will be able to learn how to adequately shift the '02 RT to control downhill speed as well as I was able to do in the pickup.

[Sensfan]

... If I had been aware of the difference between the 4 and 6 speed transmissions, I think I would have opted to look for and purchase a 2010 RT. I totally agree that speed control with the power train going off these high passes is vital to preserve the brakes for when you have to stop and I have hope that I will be able to learn how to adequately shift the '02 RT to control downhill speed as well as I was able to do in the pickup.[/QUOTE]

We are fortunate to own a 2012 RT Ranger 3500 and are spoiled by the performance of our 6.0/6 speed transmission.
Engine braking is definitely worth practising; however, I would not try it without a RPM monitor.
You could start with small hills then work your way up, I mean down ... lol.

[Floorman]

Gotten used to the tachometer in the PU. It would be a good addition in the 02 RT

[Sensfan]

Originally Posted by Floorman

Gotten used to the tachometer in the PU. It would be a good addition in the 02 RT

For sure.
I also use the RPM for climbing hills. With the cruise control on, I lead hills by increasing it by a couple of hundred, then manually dropping the transmission down. I continue to monitor, which may or may not result in additional manual tweaks or gear changes during the climb. I have gotten quite good at “hearing” the RPM increases or decreases during the climb, which really helps keep the RPM in the sweet spot. The gas-saving game is to simple: try not let the Cruise Control kick in on the hill.
Approaching the top of the hill, I upshift as needed.

[TX-Trek]

Originally Posted by Floorman

Gotten used to the tachometer in the PU. It would be a good addition in the 02 RT

Totally agree. The rpm display in the cluster when manual shift is selected (2010) is a big help. I can monitor rpm and gear selection at the same time.

You guys probly know but I had to learn the hard way. Just because the road has been level for a while doesn't mean it won't suddenly change. I got caught out in "D" in a significant decline. By the time I got stopped at the side all 4 wheels had light smoke coming off the brakes along with hot pad smell. I checked them all with a laser temp gun, obviously hot but luckily not hot enough for damage. Waited an hour for them to cool. Since then as we're traveling in any terrain I leave it in M6 - fine for regular travel but able to downshift if needed.

[Floorman]

Like to think there has been an evolution of driving skills all these decades on the road. Just when you think you know it all then there's forays into the Rockies and the Canyon lands. Getting the engine rpm on the flats in that "sweet spot" holding mph allowing the vehicle to almost glide along is a step in evolution when you come to appreciate the machine. I'll admit to kissing the steering wheel after many miles of hill and dale let alone the adventure of Colorado passes and the vastness of Canyonlands. Thanks for the comments. Good Roads

[booster]

Originally Posted by Floorman

Gotten used to the tachometer in the PU. It would be a good addition in the 02 RT

Put in a Scangauge or other monitor. Scangauge will give you trans temps, water temps, rpm, and a lot of other items in real time.

[Floorman]

Thank You B. Looks like the new ScanGauge III is the perfect solution. Here's the link and only available at this time direct from ScanGauge. https://www.scangauge.com/products/p...scangauge-iii/

I'll post a review at some point