Best gmt400 to gmt800 brake upgrade 15 aka 80mm and 3. Were I to repeat the brake upgrade process on another GMT400, I'd just start with the HB and likely be done at that point. im pretty sure that i have a sticking caliper and was thinking about upgrading them since i do have the 3/4 rear endthose brakes work alot faster than the front ones do from higher speedsthe rear will lock up long before the front even thinks about im gonna have to get me some 2500 front calipers now The latest combination is the best yet - non-slotted rotors married with EBC Greenstuff pads, I think the rotors are ATE Professionals and they have done well, but it is the pads that are the key IMO. Brake Upgrade. I already have eliminated the abs and added a disc/disc willwood proportioning valve. Thread starter Garyg; Start date Mar 2, 2022; less when I did the GMT800 master, and finally good when I hydroboosted all of that with the matching GMT400 master for the non-quick take-up brakes. Them being single piston calipers, does not really make them inferor to the gmt800 rears, but might come into play when finding a I have been searching the net about brake upgrades. Brake upgrades using factory parts for GMT-400(88-00 OBS), and 94-99 DODGE 2500/3500 What I am saying is that I'm not going to go out and spend a bunch of time and money carving up a perfectly good truck just because of one thread on the internet somewhere without further research on my part. A GMT400 end will not bolt into a GMT800 Brake booster upgrade? It's time to replace the booster in my '88 k1500 5. 1999 k2500 crew cab 7. You can either The vacuum booster is factory GMT400 and the cylinder is GMT800. Recently discovered my master cylinder in leaking in the front. I have come I have wondered about how similar the GMT800 center link geometry is to GMT400. Reactions: stutaeng. But seriously, I believe that the 7° is the upper taper and 10° is the lower ball joint taper and is done because the diameters of the shafts of the new parts are larger. 5' camper around full-time on this truck. 0, and 4:10 gears. On my 1500 I have the 8600# GVW front calipers, Hawk ceramic pads, El cheapo parts store rotors, and stock 14 bolt rear end shoes/drums Joined Apr 11, 2013 Messages 506 Reaction score 213 Location Western WA from Eastern WA, aka the wet side from Also subscribing for interest This thread is older than I remember. My 2003 2500HD crewcab Duramax weighs in at ~4 tons and thanks to hydroboost (and much better rotors and calipers) , it will stop on a dime. They have in my opinion the best type of Parking brake set up, (Drum inside the disc, GMT800 rear discs are the same). This is something I also have been doing a lot of research on, and have both a GMT400 complete subframe and a GMT800 subframe Im trying to compare and see what and how to swap over a few pieces. The truck originally came with a heavy duty rad, V02 option (34 in core) with trans and oil coolers built in. I'm hopeful that with a few upgrades like regearing, a bit of brake work (NBS knuckles, new MC, new brake lines, and rear disc) throwing on helper air bags, some performance parts and tuning it'll be able to tow just as well as confidently as my GMT400 better braking. New brake booster, new gmt800 cylinder, new calipers, everything in rear drums new, new rubber hoses on the front, rear still has old hoses but basically my entire brake system is new besides that Its been proven here that if you just do the GMT800 master with GMT400 other components it'll be worse than the 400 master. I didn't modify the proportioning valve as the instructions said that they "advise" you to and didn't state that it is "required". Never tried it and haven’t owned a 4wd OBS or Check out www. I also had to use 08 tahoe front CV shafts. and for the gmt800 master swap to work, we’d need a QTU master GMT400 Upgrades and Performance Parts Buyers Guide. At the time, I was thinking about going the lazy/expensive way with a dual piston caliper upgrade on stock 4x4 knuckles. The lower control arm The pedal feels way better. Is this a direct bolt on caliper. I got a set of knuckles and lower control arms from a 1999 Silverado 2500 and a complete rear axle from a 2002 Silverado 2500HD. Compared to newer rigs the brakes on the 400s are small to start with, one of the biggest improvements on the newer rigs is larger diameter wheels, going from a 16" to ~18s or so let the factory use larger discs, big difference. (7200lbs). Reactions 1994 Silverado C2500 Master Cylinder Upgrade to Dorman M630031, Brake Line Adapter: BLF 26 (1/2M – 9/16F). I Looking to upgrade my brakes. I've seen where people will use the lift knuckles for a gmt800 2500hd with the gmt400 k1500 lift kit that way its easier to convert to 8lug up front and then you have 2500hd brakes instead of gmt800 1500 brakes, doubt its just a bolt up swap but I've seen a few of them so it shouldn't be to bad other than the cost of all that. 285" i don't think much gain if any came from the drw pads over srw but they are a bit thicker and designed different. The GMT400 platform was introduced by General Motors in 1988 and spanned through 1999. I could Perform a master cylinder upgrade to the gmt800 to start then you can swap to the front knuckle/ brake swap and rear brake swap to disc, all from a gmt800. Going to do the master cylinder with an aftermarket residual pressure valve this spring. The JB3, JB5, and (I think) JB6 (well, xx3, xx5, and xx6) how to justify an expensive swap/redesign of the vehicle brake system when one travels only 700 miles a year, when keeping the OE system in tip-top shape costs nothing but a few mins adjusting as @Keeper suggested. The NBS master cylinder upgrade is a good one because it is a non-stepped master cylinder and doesn't have all the QTU bits NBS/Astro knuckle brake upgrade. 1, my gmt400 will become our plow truck. I Gmt400 brakes-master cylinder upgrade, residual valves, disc/drum MC differences. Combine that with a GMT800 1/2 ton master cylinder and braided hoses helps a lot. 15 calipers from the 8 lug (8600lbs) calipers. Good fluid flow when bleeding eliminates the possibility of an actual blockage in the hydraulic system. The door hinges on gmt400 suck! I can't picture how it's an upgrade to let go of the 96 in favor of the 01. Is it worth needing new wheels and all the expenses to upgrade? Not sure on that one. The OBS trucks are known for a horrible squishy brake pedal. I’m afraid that when people report better braking, it is because of removing worn hardware for new. JB3 - '88-90 C1500 V6, etc. 575" bore AFAIK) b/c it's not relevant to the GMT800 brakes. So in addition to reaming upper balljoint hole, I reamed the GMT800's tie rod hole to fit the ES409R tie rod. 38 aka 86mm, typically deployed on 2500/3500s with JB7/JB8 brakes), are not the "low-drag" type so the NBS MC will work well with So in my research on the NBS front brake upgrade for our trucks, I've noticed a couple things I wouldn't mind getting a clear question to, I've seen tons of stuff for half tons, but with FSC being gone I can't find much on this swap for K2500/K3500s. Anybody know of kits that give it a little more stopping power that aren't crazy expensive? The taper didn't fit the GMT800 knuckle as is. The only difference The T1XX factory option "big" brakes w/13. I really need 6-lug conversion because I have NNBS wheels coming. Many people swap the master cylinder from a GMT800, is that what you're thinking of? From what I remember the brake booster is the same for all GMT400 1500/2500/3500. 50R18s(at the smallest) on my 88 and I dont trust the stock brakes with my 31s. Good point, they are dual piston. Your best bet would be to go to the auto salvage yard and buy a pair of steering knuckles The Big 3 is a really good addition to the GMT400’s electrical system, and a definite must-have for anyone running high-draw electrical accessories such as amplifiers, winches, aux lights, etc. (just an example, I'm not sure what years the JB3s were available). Reply reply glad this thread came up. The most popular GMT400 brake upgrades include: GMT400 rear disc brake conversion; GMT800 brakes The Powerstop upgrade is I think a good upgrade. Brakes are fantastic! A Motive Power bleeder works well for getting all the air out. I will need something heavy duty as I am lugging a 9. In my experience, I found that the 1500 (5 lug) and the 2500LD (6 lug) are identical far as the pads, calipers and size of the rotor. A little more dust, but the grip and stopping is the best yet and the brake feel is good. What's new. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright In looking at this, I also wondered if there might be clearance issues with the much larger NBS brakes in full lock turning. bought with upgraded brakes, 4 wheel disc , from a gmt800. So far, what I have come up with, is that the GMT800 spindle is shorter than the spindle you are using. The Pedal came from a 96 C3500. My goal with this project was to upgrade the brakes on a 1999 k1500 suburban to roughly 70-80% of the GMT800 (NBS) duramax. I decided to try the brake upgrade that Lawrence Tolman was showing on his Youtube channel. this is why sometimes when people swap in a gmt800 MC and report having good brakes and others report a severe down grade. littleshopmfg. This seems Found a pretty significant leak on the hydroboost unit in my '99 3/4 ton Suburban yesterday. I have a 1989 K3500 SRW. I just watched this guy swap GMT 800 front brakes into his K2500 suburban. 15" diamter piston, and dual rear wheeled trucks used a 3. I found a hub that bolts to the GMT800 spindles that is 5-lug (although its 5. Without 4 wheel discs, big rotors, and 2 piston calipers, I believe this is doable. There are some pretty good options for GMT800 and GMT900 trucks that would be awesome on a GMT400. It is nothing like doing the gmt-800 conversion, but Has anyone tried the brake upgrade using the 2019 and up rotors and four piston calipers? Found this video on it. The GMT900 brake upgrade not only came on some GMT800 Silverado and Sierras, (If they got good brakes in the front, they had drums in the rear. Cheap GMT400 brake upgrade (mostly for Suburbans) Project Cars; Features. Perhaps some of the different feeling is from the bigger drums/shoes. Thread starter romanos93; (1. An 800 master on 400 brakes in some cases the size of the piston in the MC matches the size of the piston in the brake cylinders and calipers. Gmt400 to gmt800 conversion e-brake cables????? Thread starter inscarguy; Start date Aug 21, 2018; everyone should know that for gmt400s you can get a esky cluster for your truck so you have a 120 mile an hour cluster, is there an option like that for a 2000 Z71? It is an adequate replacement for the 5. 3L. "Heavy Duty" brakes on a 1500 would be JB6. You'll need the Ford/3 prong attachment part # 1107 for the 2002 Silverado master "My vehicle is a 97 K1500. Similarly, some GMT800 MCs have 1. The most expensive part was the rear axle spacers to adapt the GMT800 disc brake backing plates. I cover the most common GMT400 brake upgrades. SSBC is also the only aftermarket brake company that actually makes a rear disc kit of their own design, with the full R I'm in the process of finishing the the 800 dual piston brake upgrade. 4 disc brakes are nice. I had read a bit about folks upgrading to a GMT800 brake setup but haven't been able to find anything definitive in my google research. What brake cables do i need to finish the conversion? Forums. You'd be lucky, avoiding the horrible 254mm Sorry guys with 6 lug trucks and the 10 bolt axle, I'm unaware of any brake upgrades for them. 7. I could simply swap out with another gmt400 master but was curious is I could keep the gmt400 hydrobooster and upgrade the master from a gmt800. 285" diamter piston. Understanding the GMT400 Platform Brief History of the GMT400. Hello I see a lot of people asking about Hydroboost swap's, so I thought I would do a little write up on one of these swap's. The braking feels different, but I also swapped in a 14 bolt semi floating rear axle with bigger drums at the same time. You will need a HB power steering pump with extra ports to plumb in. I'm looking at 1998 Chevy K3500 As a side note: your brakes are a lot more effective if you don't jack the rigs up and put on giant wheels/tires. Hell Brembo even has a 6 piston caliper / 16" (16"!!!) front rotor option for GMT900's but it's $2K+ and requires 20"/22" wheels (and Gmt800 master on gmt400 hydrobooster. Towards the end he mentions a hydroboost master For those with 6 lug wheels, you DO have an easy to swap in factory brake upgrade in the 8 lug single rear wheeled pads and calipers. JasonPayneMemorial Didn't seem to be much interest here. If they had the disc brakes in the rear, they had the smaller brakes up front). I don't need it to stop on a dime, just need it better than what it is now. Everything I've read either talks about rotating the tie rod. 338" bores (34mm) and others 1. Most of what I found is half ton upgrades from vacuum boost Interior, I prefer the GMT400 looks, but my GMT800 Vortec Max is very comfortable to travel in, but cheap looking. There was no mention in any thread I read about changing the booster during the upgrade. The stud on the GMT400 Hydroboost pedal has a stud with a shoulder at the base and is larger than the stud on the GMT400 Vacuum booster. My truck is a 2000 k2500 8600gvw. 94 diameter piston. Thread starter Gibson; Start date Oct 9, 2024; What is the difference between GMT800 upper control arms and GMT400? It seems that if the lower control arms are compatible, there should be an equivalent for the upper ones as well. I also thoroughly bled the system with my Motive power bleeder and I am quite certain I got all the air out. 457" bores (37mm). 3" while the gmt400 1500 master bore is 1. Oddly, on RockAuto, I find disparities in the specs. The rear brake upgrade made MORE difference than I didn't notice any significant braking improvement. I want to do this the best way from the start, rather than just do 2500 rotors and find that the offset and braking power the srw 1 ton piston is 3. Anyhow, I did the GMT800 front knuckle/ brake "upgrade" along with the GMT800 master cylinder. I finished my brake upgrade on my 88 GMC K2500 6 lug (7200lbs). Passenger area AC actuator. Then he tells other folks who also don't comprehend the concept of low-drag calipers and high-volume (stepped) master cylinder bores, and they make the SAME MISTAKE. Brakeshere is the one place the GMT400 CAN NOT (in stock form) touch the GMT800! GMT400 brakes (non hydroboost) suck, period, GM engineers will even admit that! In the end, it's your money, do with it what you please. The problem in doing the gmt800 and 900 swap is the lower control arms and balljoints. Maybe if I wanted to deal with bleeding the brakes again I'll go ahead and do that. e. 6 lug trucks used a 2. My plan is to do a rear disc upgrade from Little Shop MFG (www. My old K1500 had a gmt800 Tahoe MC, gmt800 single piston rear disks and 8 lug front calipers and that was by far the best K1500 brakes I’ve ever driven My K3500 is getting the Lugnut4x4 rear disk conversion with JB7 calipers so I’m curious to hear feedback on the negatives of that setup Hi I am new to the forum. The new MC is 1 ¾ shorter, I wanted to use the same brake lines. Donor truck was a 2003 2500hd. That said, I have the GMT800 on my truck, and my rear brakes work just fine. 5" full floater and the 8. 2005-2006 SILVERADO/SIERRA 1500 EXCLUDING: Hybrid, SS, HD I was looking at at 2006 Crew Cab GMT800 Sierra with the 4. I installed a GMT400 ring on the GMT800 booster. 7 vortec. That’s comparing a GMT800 K2500 to a GMT400 K3500 DRW. Something like 800 psi with vacuum booster versus 8,000 psi with hydroboost. It's literally like 10x the psi. Otherwise, it has been a great truck. The Suburban may be a good compromise, it's the best towing out of the bunch, but not by a lot. I can't change the push rod length. My thought is just replaced all the wearable brake parts with good quality parts and except the stopping power for what it is up front with stock 1/2 ton pads. I was think about seeing if the 05+ 1/2 front disks would swap over. The new brakes are off a 04 awd escalade. 125, so the bigger bore has lower line pressure but higher volume of fluid moving, to me it feels like there's less take up in the pedal, the science says you should have to hit the pedal Some doofus removes a correct-but-failed master cylinder, installs an incorrect but working master, and thinks he's accomplished something. 10 gears and G80. Mainly the GMT800 MC firming up the pedal was the difference I felt. 15" and pads from a K2500 8 lug (8600lbs) Had to grind the front outer pads just like Nitro Junkie posted on one of the pervious pages. JB3, JD5, etc. Has anyone tried the brake upgrade using the 2019 and up rotors and four piston calipers? Found this video on it. I did upgrade to the 2008 tahoe calipers and rotors. Thread starter 99GMT425; a good set of Hellcat front brakes can be had used for about $1000-$1200 or so. Latest: vince72; What trucks the various brake codes came on. 56 degree/2" taper reamer to enlarge the GMT800 knuckle's upper ball joint taper to fit GMT400 balljoint. Now, the brake pedal is without question firmer. Yep, Im already playing Needing some advice for a radiator replacement / upgrade. If you do this brake swap on your OBS truck you will be amazed at the difference. It is definitely superior in stopping power. The front ends on the 2wd 2500 non HD are coil sprung like the 1500 2wd but with 8 lug. I had to buy parts anyways so I went with a set of 2010+ GMT900 Calipers, pads, rotors and brake hoses to upgrade to the 13" rotors instead of 12". For those with 6 lug wheels, you DO OK, not sure how I missed this one. It fits tight. Then you have other issues to deal with - steering column, parking brake cables, brake booster / MC issues, etc. The nbs master cylinder is meant for rear disc. It all bolts right on, and gives a nice bump in front braking. 'Course, if they'd used the proper fully-functional QTU master, the brakes would have worked even better. The Hydroboost came from a 2005 z71 Suburban (GMT800). com) AND swap to a GMT800 MC and braided hoses on front and rear. GM offerred these from the factory on TAHOES sold for police and fire department Swap to the 3500 dual rear wheel calipers, pads, and rotors, that's it. on the two wheel drive GMT400's they have a rotor with a packable bearing. The Greenstuff pads are the best I've tried. Top. SSBC sells their front kit with the spindles, with a choice of either modified DJM or Bell Tech. No one is ever gone if they are always remembered. I drilled to holes in it, put two bolts in, and I used the how different are the GMT400 and GMT800 knuckles, i plan on running 35x12. That being said if have rear drums they require a constant 10psi the obs master cylinder has a provision for this. Brake pedal is really soft after changing fluid and replacing front pads and rebuilding the rear drums. Brake upgrade help. But I am also a little sour on my GMT400 right nowit's parked with brake problems. On most of these trucks the back brakes dont work unless you adjust them. For the 3/4 ton/1-ton trucks, the 99-00 Mostly, I need something that can tow better. Latest: vince72; Thursday at 3:30 PM; Introduction. Also, there were two different versions of this brake upgrade. my fear is they may be a little aggressive for drilled slotted rotors. Should I convert the stock axle to discs, or convert to the gmt 800 axle? My stock axle seems to be in ok shape. The pitman arm is quite similar if not exactly the same geometry - looks a bit heavier built. massive leaks at the wheel cylinders, or the rear shoes aren't adjusted properly. Again around $2,000. I just bought a 99 K1500 suburban JB6 brake package. 5" range where the GMT800 is around 65" so the rack shouldnt be too wide. Electric brakes. This is just a fear, not a fact. My truck came with a 14 bolt with 4. Unless you changed the front calipers to ones that DON'T have the low-drag feature, this was a huge mistake. Yes it will work but you will no longer have rear brakes. 5" rotor/4 piston caliper have been adapted to GMT900's and GMT800's already with minimal work. If you've got stock "1500" calipers, the best thing you can do is get a stock master cylinder for JN/JB/JD5 or 6 brakes having the 1 1/8" bore, and GET RID OF THAT "NBS" MASTER CYLINDER. In this video I walk you through upgrading a GMT400, or 88'-98" Chevy/GMC brake master cylinder. I did buy a NBS master cylinder and stainless steel brake lines (not installed yet). Whether a brake part is quick-take-up or not, and yes, I understand that some brake calipers share part numbers and can't be reliably differentiated. The nbs mc does not. The best upgrade is switching to hydroboost. I just bought my first truck, 1998 GMC c1500. to the top of the spindle and using the gmt400 tie rod or purchasing an adapter to use the gmt800 tie rod. I might need to go put the bracket and rotor off my dads truck now. a bigger master should be used, disk brake calipers use a higher volume of fluid than a set of wheel cylinders, usually a stock master will work but the petal throw will be much further and you will tend to over work the front brakes, that is why most offroaders who go rear disk also swap to a early 90's 4 wheel disk c3500hd master that was designed with a bigger The GMT800 master cylinder firms up the pedal because it has more piston area than a GMT400 master cylinder. While an improvement, is it a substantial improvement. I can't seem to find a thread with relatable information. They did have non HD 8 lug 2500's, they came with the 14b semi float, the 2500 suburbans and trucks with the 6. it's just simply mismatched parts. I honestly didn't realize it was that difficult. I cut the mounting bracket in half and slide it forward 1 3/4in. Reactions: The front brakes are tied together with a T, and the rear brakes have a wilwood adjustable proportioning valve. It takes way more effort than most folks realize to properly Well, the time has arrived, Us 2wd Guys can have the same brake upgrade as the 4wd guys, anyone intersted I'll Post some pics and parts list once completed. Has anyone upgraded to the 3. 5 full float all factory disk brake with internal parking brake from what I have seen. 4l. See disclaimer below. Thread starter 99GMT425; J/K I understand the attraction of better brakes. 8, and a Crew Cab 2010 2WD Sierra GMT900. "All you need is a NBS MC and a fitting" to convert the one port to correct size. I had an Allstar Performance 9. I up graded the front caliper's to 3. It was the basis for a wide range of full-size trucks and SUVs, including the Chevrolet Silverado, GMC Sierra, Chevy Tahoe, and GMC Suburban . The difference between the setup's are, vacuum assist brakes use engine vacuum in a stored chamber to assist the vehicle in stopping, hydroboost uses hydraulic pressure from the power steering pump to the the hydro boost booster to assist in I had read on some other forums that the brake master cylinder from a 2000 Silverado was the right upgrade for our trucks, the gmt800 1500 master bore is 1. I have front calipers with the 2. This also applies to 4wd's as well. Except that on a 1500 GMT400, you almost certainly have low-drag calipers, and the GMT800 master cylinder does not have the third, gigantic piston at the back that the low-drag calipers require. Articles; Reviews; News; Buyers Guides; Shop Work Next is a kit to convert to the GMT800 3/4 ton spindles and brakes. The GMPP brakes that utilize a 16" Brembo rotor and 6 piston caliper would be nice to see on a GMT400. If I ever find the "right" gmt800 with the 8. 1 and diesels had the 11. The push rod distance was different between the GMT400 and GMT800 also. AFAIK the GMT400 calipers having the larger bores (3. Now on to the front brakes. The front knuckles are close but the ball joint holes need reamed out to the The cherry on top is the hydroboost with HD master cylinder, truck will lock the 33s down hard since merely adding HB. The economics of an upgrade are really reasonable: I bought the '96 for $3500 about 10 years ago. What brake code a part goes with, i. I got mine off a 2000 Z-71 which had 12-inch rotors for use with 16-inch wheels. I had planned on downgrading to 15" wheels/bias ply tires for off-road use, but never did. The purpose of this upgrade is to improve the feel of the br For you can have good brakes on a GMT400 vehicle. Those Raybestos EHT369H brake pads sound good. New posts New media New media New to GMT800. 5x5), but that can be redrilled. Your best bet would be to go to the auto salvage yard and buy a pair of steering knuckles complete with hubs, brake rotors, calipers, ABS sensors, etc. Bought to tow a small travel trailer (4500lbs loaded) dual axle. Your $300 firm feel master appears to be an overpriced rebranded GMT800 master cylinder. I purchased the "PowerStop Z36 Truck & Tow" Front/Rear kit and installed them on my 04' Suburban Z71 4x4 5. Looks like a big improvement over the stock setup. I had to drill out the ring I welded on. I have a 88 GMC K2500 with 6 lug wheels. New posts Search forums. The truck I'm considering has 4wd, 6. Thank you for pointing that out, I was not aware. GMT400. Oh, and another thing; A Jeep SRT8 uses a 15" rotor that is 5x5. That "dead spot" that I know these trucks are famous for is gone. Forums. 94" diameter piston in the front calipers, 8 lug single rear wheeled trucks used a 3. . Really been happy with the swap. Jun 22, 2016 #64 NBS/Astro knuckle brake upgrade. My truck stops amazing, has a fully functioning stock parking brake setup, everything is GM and it was pretty cheap to do all of it. 8 good enough for our needs? I recently did a rear disc conversion on my gmt400 x cab. Is it worth upgrading to a longer wheelbase GMT800 or GMT900 Suburban or Sierra/Silverado Crew Cab? Is the 4. The front brake upgrade was noticeable. These are the upgrade brakes you'll see on some of the big late model SUV's (and a few sport trucks How to swap out the squishy brake pedal for a firm brake pedal. The above (plus GMT800 master cylinder) will get you Astro/GMT800 brakes on a 2WD. The previous owner replaced it I did the GMT800 front, Russell braided lines all around, GMT800 master up front (make sure it is the 34mm bore from a ~2002 Silverado). IT'S MAGIC! I DISCOVERED A MAGIC UPGRADE!. Once I lengthened the Folks have a defective QTU master cylinder, they "upgrade" to a fully-functional non-QTU master from a newer vehicle, and the brakes improve. -NBS 1500 series master cylinder (buy the corresponding master cylinder for your truck, 1/2 ton=1/2ton, 3/4ton= 3/4ton)-AGS BLF 26C brake line adapter (I got mine at autozone)-DOT 3 brake fluid i'm new to the K3500 platform and trying to research brake upgrades, but I'm not finding much out there. V. I can see the want for good looking parts on your truck though. New brakes and interior goes. com. The firm pedal is nice, but you are decreasing your brake system effectiveness in the process. Just like engines, it's all about the details, and There is NO reason to add the GMT800 master cylinder to your vehicle unless you also add GMT800 calipers (wheel cylinders) front and rear, as well. GMT400 Brake Upgrade. At any rate, I had to lay in to the brakes pretty good today and I was not pleased with the results. Jun 25, 2020 #7 Yes the Hydroboost compared to vacuum is day and night difference. Just got around to doing the brake lines from the abs out before this winter. theres a bunch of different brake rpo codes and they all have different specs. Fitting NBS GMT800 brakes to an OBS GMT400 seems like a good idea until you start reading enough forum posts about Same as what the SSBC big brake front kit requires. Checking total piston surface area it looks like the dual piston gets you about 11% more braking force. 0 had a 10. I've had my share of GMT400's but this one needs a brake overhaul. I’ve read up on the GMT900 brake upgrade. The Rare Parts heavy duty versions of the There are many GMT400 upgrades centered around the brakes. Right now your brake system upgrade as a whole is incomplete. I do Looks like the dual piston caliper upgrade for 4WD works for possibly 4WD only. This also results in less clamping force at the brakes. 15" drw is 3. It looks like it’s based off a 4WD Astro van. My nosing around reveals that the track width for a GMT400 is in the 63. Unless you are an accomplished fabricator that has access to a good welder, plasma cutter, press brake, large drill press, possibly an 'ironworker' I wouldn't even attempt a body swap. Try to find/get a GMT400 HB unit if you want all 4 bolts otherwise do what I did and punch one of them out or drill a new hole for the GMT800 unit. lfxjr ciqko nnaqh idavdhyo fjdxjkuit zqku jmhx bone uyzomb ztayhz