99 and older Suburban K2500 wide brake drums - corrosion.

[staatsof]

I've looked and a lot of articles on the rear brake conversion to discs and so far I think I'm going to pass on that approach. This is for a vehicle that's driven a lot around town and used as our only snow vehicle so the lack of protect via splash guards for thos kits has me saying no. Also, they're all dependednt on that could of year hard to find caliper off an Eldorado.

With that in mind my rear drums and backer plates are real mess on this vehicle . I don't know yet if I can turn the drums, they've been done at least once already but amount of corrosion on the outside is horrific. I plant on new backer plates which I may coat with POR 15 paint. I'll also be putting in all new brake hardware, a new drop sown hose in SS braid as well as a stainless on axle line. But where I can clean up the old drums or have to put on new ones I would still like to be able to prevent corrosion on the outside of them. I know painting them is frowned upon due to the reduction of heat dissipation but is this really that big a deal on these trucks. I currently have Porterfield shoes which are hardly used after more than 10 years so I know this thing hasn't been right for a long time. They just don't stay in adjustment but after a lot of reading I think I've learned much more about that.

Any thoughts out there on all of this.

 

[Twisted Steel Performance]

You could consider a Ceramic Thermal Dispersant coating on the drums, that would provide better cooling along with corrosion protection ..

If your drums have been turned once that you know of it would be a good idea to purchase new ones, new drums and the coatings would mean you would have new brakes for a very very long time AND no more rusted drums....

If you want to go the cheap way out and use your drums, purchase a couple gallons of "Phosphate acid" at Home depot or Lowes, soak the drums a few days, it will remove all the rust...

 

[Twisted Steel Performance]

This is what the coating looks like on a rear disc for our trucks... it is a lifetime coating....

 

[WarWagon]

I adjust the rear drums every other oil change - aka 6000 Miles or so. (Every oil change when new.) Did I mention adjustment of the automatic "never ever will self adjust period" adjusters is the only way to get the rears to "do something?" Maybe if you slam brakes in reverse to where the front wheels lock up for 50x in a row...

Use the expensive $100 shoes Aka Raybestos or Wagner. Makes a big difference on the rear drums actually doing something. @RockAutoLLC has them for about 1/2 the over the (above) parts counter cost.

If in doubt just replace the proportioning valve.

New drums like anything else have quality issues. Put the drum on backwards and spin it to make sure it's true and round, yes new out of the box do this test!

Drum diameter of a turned and worn drum won't match the new shoe very well. (Noise and longer wear in time.) So I do recommend new drums to start with - again don't go with the low bidder. Because of the weight I recommend going local to get these as shipping returns are a heavy PIA.

Conversions are out there as you see on here and some don't need the Eldorado caliper. It's all in what you want as @Big T has gone all out to stop on a dime.

 

[staatsof]

I should mention a couple of very big limitations first. I cannot work the vehicle myself for something like this. There are some restrictions about that where I live and ... with a vehicle as heavy as this I don't have all the tools required so ... I need to take it to my local mechanic with everything ready to go so the having new brake drums coated is probably my only route if I'm going to keep the drum brakes.

This is what the coating looks like on a rear disc for our trucks... it is a lifetime coating....

View attachment 53552

View attachment 53553

The salt here is incredible. My Suburban is in the shop today getting a new steering box and some other front suspension work so I was inspecting what else I want to replace. I should have taken photos of the backer plates and drums so that you could see what we're up against here, it's just brutal.

You see a lot of SC on the roads in SC?

 

[FellowTraveler]

On the topic of POR 15 this paint does not have any UV inhibitors and should only be used as a base coat with a better quality paint over it like Eastwoods chassis encapsulator which is resistant to UV radiation.

In today's world even radiator and heater hoses can be had w/UV and ozone inhibitors, then there are many types of water based clear coatings gloss and mat w/UV blockers that can be applied to all rubber components.

 

[Twisted Steel Performance]

I should mention a couple of very big limitations first. I cannot work the vehicle myself for something like this. There are some restrictions about that where I live and ... with a vehicle as heavy as this I don't have all the tools required so ... I need to take it to my local mechanic with everything ready to go so the having new brake drums coated is probably my only route if I'm going to keep the drum brakes.


The salt here is incredible. My Suburban is in the shop today getting a new steering box and some other front suspension work so I was inspecting what else I want to replace. I should have taken photos of the backer plates and drums so that you could see what we're up against here, it's just brutal.

You see a lot of SC on the roads in SC?

No I don't see that much salt, but I do apply the coatings for people all over the US. This coating has passed the 6500hr salt spray test from the manufacture, that is continuous spray.. It surpasses any paint on the market, even zinc plating...

 

[staatsof]

I adjust the rear drums every other oil change - aka 6000 Miles or so. (Every oil change when new.) Did I mention adjustment of the automatic "never ever will self adjust period" adjusters is the only way to get the rears to "do something?" Maybe if you slam brakes in reverse to where the front wheels lock up for 50x in a row...

Use the expensive $100 shoes Aka Raybestos or Wagner. Makes a big difference on the rear drums actually doing something. @RockAutoLLC has them for about 1/2 the over the (above) parts counter cost.

If in doubt just replace the proportioning valve.

New drums like anything else have quality issues. Put the drum on backwards and spin it to make sure it's true and round, yes new out of the box do this test!

Drum diameter of a turned and worn drum won't match the new shoe very well. (Noise and longer wear in time.) So I do recommend new drums to start with - again don't go with the low bidder. Because of the weight I recommend going local to get these as shipping returns are a heavy PIA.

Conversions are out there as you see on here and some don't need the Eldorado caliper. It's all in what you want as @Big T has gone all out to stop on a dime.

I'd like a more reliable and easier to service setup than the 13 x 3.50 drums I have in the rear but I kaven't seen any conversion setups for sale that also have adequate Ebrakes. I do hear about utilizing other OEM parts to accomplish this. It's pretty daunting for someone not very familiar with all of the truck mechanicals, I'm a sports car guy, to pour through with any certainty as to what will fit and what will work. Perhaps not for some of you guys but then you live, eat and breath this stuff whereas I'm just a visitor so I don't have the background maybe you can just assumed to have?

It took me a couple of days to figure out that my Suburban has a 14 bolt G80 full floating rear axle but does not require removal of the hubs to pull the drums off. AFAIK there's only one vendor out there that has a kit for that and he doesn't even have the Eldorado calipers currently. Not that I want them anyway and I'd like a splash guard/backing plate for these brakes.

So what I'm trying to uncover is whether there is a way to use factory parts from other GM vehicles that my mechanic can bolt one WO a lot of fabrication save perhaps new brake lines/hose and Ebrake cables as well as some trimming or modification of some OEM backing plates?

Or does any solution require a lot of axle swapping, fabrication and welding?

Thanks

 

[staatsof]

No I don't see that much salt, but I do apply the coatings for people all over the US. This coating has passed the 6500hr salt spray test from the manufacture, that is continuous spray.. It surpasses any paint on the market, even zinc plating...

One of the vendors, within 80 miles of me, offers these sorts of coatings but says a thick powder coating would be better for corrosion protection which is my primary concern. That will hurt the thermal issues of course but I'm not so sure that's as big an issue for me at this point. There isn't going to be a lot of hauling the race trailer anymore for me.

 

[THEFERMANATOR]

If you have the drums that slide over the hubs, it is possible to upgrade to the mewer discs. There was a company making the adapters for them, but last I checked they were out of business. I just redid my rear brakes and I'm kicking myself for not going to discs. For what I spent doing everything, I think disc would have been cheaper. And I don't like the single piston conversions out now either. I need to dig into it deeper, but I believe Dodge used rear discs that may swap onto our trucks. Worst case scenario is you cut the current backing plate mount off, and have a new larger flange welded on to hold the new style e brake and caliper mount in place onto your axle. I regret not digging into this furthur when I did mine as my shoes are being slow to bed in, and I used new drums, shoes, wheel cylinders, everything but backing plates was replaced, and it felt like I had air in them for the 1st 50 miles. Could set the ebrake and have awesome pedal, but as soon as I released it, it was soft again. It didn't help I fooled around and got the wrong brake booster either that provides way to much assistance, but that is easily remedied.

 

[staatsof]

If you have the drums that slide over the hubs, it is possible to upgrade to the mewer discs. There was a company making the adapters for them, but last I checked they were out of business. I just redid my rear brakes and I'm kicking myself for not going to discs. For what I spent doing everything, I think disc would have been cheaper. And I don't like the single piston conversions out now either. I need to dig into it deeper, but I believe Dodge used rear discs that may swap onto our trucks. Worst case scenario is you cut the current backing plate mount off, and have a new larger flange welded on to hold the new style e brake and caliper mount in place onto your axle. I regret not digging into this furthur when I did mine as my shoes are being slow to bed in, and I used new drums, shoes, wheel cylinders, everything but backing plates was replaced, and it felt like I had air in them for the 1st 50 miles. Could set the ebrake and have awesome pedal, but as soon as I released it, it was soft again. It didn't help I fooled around and got the wrong brake booster either that provides way to much assistance, but that is easily remedied.

Putting the parking brake on until they are just about to touch does help but ... I had to do new pads up front last winter, I've been using Porterfield F & R for years now, so at the same time I got a set of rebuilt Cardone calipers that are powder coated and whatever pads my mechanic could put on quickly as we needed the car in a hurry. The rears could not be bled because he was afraid that the bleeder screws would just snap off. I now have SS ones on the front and some ready for the rears when I replace those cylinders.

The corrosion on my rear backer plates is just grotesque at this point.

My pedal is soft and braking performance is impressively awful as well right now. I'm about to pickup my Suburban after it got a front end frame welding repair, new upper ball joints, new tie rods, Pittman arm, new steering box (Amazon has them for $5 from Cardone after rebate), and I had the the entire power steering system/hydroboost treated with Seafoam and thoroughly flushed. So up next is dealing with the rear brakes.

I hope it all works better when I pick it up. I was having a real issue with the steering not self centering after the welding and upper ball joints were replaced. It was tight and if you took off your hands in a turn it would just keep going in that direction. I'm not confident as yet that we found the silver bullet but today after it comes out of the alignment shop we'll learn more. The first shop is very experienced in working on big trucks but they diagnosed it as a stiff steering gear box. We found slop but not stiffness so we dug some more. I'm hoping the new alignment shop will spot any issued with the previous alignment though the toe was completely off after the new tie rods. Perhaps the castor was off. Nothing we did this time around should have affected that.

As everyone is aware the brakes on these vehicles suck but mine sucked more of late and I suspect it's in the rear cylinders or perhaps that prop valve? Perhaps some air got into the rear circuit somehow? It shouldn't have but it's good to check and be certain. I do have a brake pressure gauge to measure what pressure is reaching the calipers and cylinders but with the bleed screws frozen in the rear I have to replace them before I can test the system.

Nothing but fun of late ...

I saw your suggestions for the rear drum brakes. I think I already have the equivalent of the HD shoes but I could put the bigger cylinders in. I may just replace the prop valve at the same time. After 19 years it may also be time for a full new brake hardware kit, new backer plates and drums. That's actually much more than one of those disk conversion kits but their rear calipers with an integral parking brake leave me unimpressed plus there's no backing plate.

The rest of the vehicle is more than good enough as a hauler and winter driver. The interior is almost mint leather.

 

[WarWagon]

Keeping the rears adjusted is a PIA. But this keeps them working and the pedal high. Sub it out to your mechanic with oil changes. Not hard, but, if snow or slush... I would sub it out rather that lay in that.

Firm brake pedal would require better, like 2 or 4 piston, calipers. Because after the brake hose flex the calipers flex.

4 wheel disc stops faster than obsolete drums. Otherwise some upgrades you can do to the drums while you are there.

 

[Twisted Steel Performance]

The conversion kit i bought has a separate caliper for the parking brake.

 

[Twisted Steel Performance]

TSMMFG.NET

 

[staatsof]

Keeping the rears adjusted is a PIA. But this keeps them working and the pedal high. Sub it out to your mechanic with oil changes. Not hard, but, if snow or slush... I would sub it out rather that lay in that.

Firm brake pedal would require better, like 2 or 4 piston, calipers. Because after the brake hose flex the calipers flex.

4 wheel disc stops faster than obsolete drums. Otherwise some upgrades you can do to the drums while you are there.

Yes I've seen the wheel cylinder upgrade ideas. I already have high performance shoes and I guess I could change the prop valve but I have to get those ugly old drums off to do either of those and that'a job for my mechanic for a lot of reasons. It probably means a full rebuild of the rear brakes including new backing plates. That's probably over $1K and I suspect that will bring only minor improvements. I've just never had great luck getting the rears adjusted properly. I think that probably takes two people for about 1/2 hour and up on a lift. I suspect if one guy just takes a stab at it then it sucks. Like everything it's a struggle to get people who work on your cars to really do it well.

A disc conversion solution that would work for my requirements would probably be best and perhaps cheaper. I haven't found one yet. They're all focused on off road activities.

 

[staatsof]

TSMMFG.NET

I've already seen their stuff. Thanks.

 

[Will L.]

As long as we are spending your money here, you’re in a rusty area? How are your brake lines? I hate throwing parts at anything- except brake systems. Can not be too sure with brakes. Maybe new brake lines at the same time as proportioning valve?

Totally would get disks on there pricey on day one but long term cheaper, pads last longer, and off corse way better stopping.

No way would I spend more money on drum brakes for anything except my ‘43 Willy’s. That rig stays stock.

Call brembo directly. Excellent customer service when I delt with them in the past. Maybe they have a kit.?
What’s wrong with the kits mentioned above?

 

[staatsof]

As long as we are spending your money here, you’re in a rusty area? How are your brake lines? I hate throwing parts at anything- except brake systems. Can not be too sure with brakes. Maybe new brake lines at the same time as proportioning valve?

Totally would get disks on there pricey on day one but long term cheaper, pads last longer, and off corse way better stopping.

No way would I spend more money on drum brakes for anything except my ‘43 Willy’s. That rig stays stock.

Call brembo directly. Excellent customer service when I delt with them in the past. Maybe they have a kit.?
What’s wrong with the kits mentioned above?

I've already answered that above. The only brake line that concerns me is the one across the rear axle that has the spiral protection wind on it. The undercoater missed that one and it doesn't look too hard for me to replace myself. Supposedly InLine has that piece in stainless. Stainless is such a PITA to work with though. I have another car with some very unusual brake and clutch plumbing in very tight quarters that I'm using Cunifer (copper/nickle) tubing on because it's so easy to bend and it's corrosion proof. Perhaps they can make that piece with the same tubing and add the SS spiral wrap on it?

 

[WarWagon]

I've already answered that above.

Well more than one of us has missed it then. @Will L. is sincere in asking why you don't think the kit would work and I sincerely have the same question. What are we missing?

I'd run the kit in a heartbeat and IMO it' almost in the $budget. Esp. because I Fing HATE obsolete drums and the way you can't "feather" the kickback from them when coming to a complete hard stop. One floor jack, jackstands, with the front wheels blocked I spin the rear tires while under the truck and snug "click-click" the adjusters up with a screwdriver through the backing plate till I hear them start to drag. I have it down to 10 min flat. Faster with help to spin the tires.

Perhaps we are outright dismissing one concern for the following reasons: Snow/water/rain/dirt on the rotors is no real concern if you dry the brakes by applying them early. Slotted rotors for the rear help get wet road spray off the rear brakes as water does reduce their ability to work. If wet road spray is concern #1 then you have no choice but to stay with rear drums and good luck drying them out after being submerged. Frankly wet disc brakes stop better than typical out of adjustment to the point of useless "dry drums". Because the rears do dry off, start to work, and do surprise remind those of us from "dry" areas when it rains. I drive a Dodge now and part of the reason is GM's inability to get a working parking brake on 1999MY+ 1/2 tons, initial bad dust shield design causing rapid rear rotor wear, and going back to Obsolete technology rear drums in 2005 on 1/2 ton pickups. And those 2005 drums didn't even have cooling fins on them. Guess what GM replaced under warranty for me after the first time I used the pickup as a pickup and put the parking brake on? Yep, warped drums.

The OEM drum in hat 4wheel disc parking brake is pure garbage for some years esp. the 1/2 tons with the one piece shoe. So the above kit appears to have 2 separate parking brake options that are better than the OEM design for a parking brake. The kit looks to be strong enough to call the parking brake "also" an "Emergency Brake" where the drum in hat designs really aren't. Rust where you are at... I don't see a real difference in rust out time between it failing anyway never mind the frozen parking brake cables where one wouldn't use a parking brake in freezing weather for fear that the can stay on from ice locking up the brake cable. Maybe coating the components would buy you some time.

 

[THEFERMANATOR]

I believe his concern was the parking brake. That said, those same kits for our trucks are sold to Dodge owners, and several who bought them said they yanked them off and went back to drums because the parki,g brake was horrible, and poor rear braking performance because they couldn't easily find a different proportioning valve to go in the kelsey hayes abs unit for 4 wheel disc brakes.