How to: NBS master cylinder swap for firm brake pedal

[nomad]

then comes the variable steering issue.

Actually EVO isn't an issue at all, you simply remove the EVO selonoid, install a standard PS pressure union/valve (easy find in a junk yard) use a pressure hose from a 96 (or the one included with my kit) and your good to go.

I dumped EVO some time back, easy mod.
Dan

 

[SunlitComet]

or you use the delete kit.

 

[nomad]

Thanks to the forum members who PM's me wanting to purchase the Hydroboost,

Retorq was first on the draw with the cash, congrats to him as he got a really nice unit at a steal!

 

[MarkD51]

OK folks, just a quick re-hash, as I'm a new dumb guy here.

Vehicle is 1997 Tahoe LT, 5.7ci.

To do the NBS Master Cylinder swap, I need 1 new NBS (2002 Tahoe for say) Master Cylinder, and 1/2"-9/16 Threaded Adapter, and that's it?

I don't need a 2002 3/4 ton surburban MC, the 1/2 ton is the correct part to swap onto the 1997, correct?

I've never liked the brakes on this truck, they got a little better after upgrading to Stillen larger 3/4 ton Calipers, Slotted stock size Rotors, 3 Stainless Brake Hoses, and better Ceramic Pads, but recently my brakes have gone to total hell.

Might need a Booster, not sure just yet, will have to check-test.

I'm going to take my truck soon for this brake service, do a good bleed, but might consider the MC Swap as well.

Will a brand new NBS MC from Oreillys-A-Zone be fine, or do I have to run to Chevy for such?

Sorry for being a pain, and will appreciate you folks educating me.

At this point I don't think I'll need a Hydroboost conversion, just would like making my brakes work as they used to, and a bit better from the pathetic stock set-up.
Thanks folks, Mark

 

[nomad]

MarkD51,
My suggestion to you is to read as much as this thread as you can stand. The answers to all of your questions are here. Many have completed this mod and have been pleased, others have not.

IMHO I have tried the NBS MC and was not pleased with the results, many here will tell you the NBS will give you a firmer pedal, that is absolutely true, but if you have a properly working brake system in your Tahoe you will find the original factory setup will actually stop in a shorter distance then a system using the NBS system.

Another issue, the NBS system was based on rear disc brake technology and the piston sizes are different then the obs mc, this results in more pressure to the rears where you will find them locking up before the fronts. True the ABS will try to compensate for this and work ok on a dry surface. But in the rair or snow look out!

Another complication is the ABS system, unless you can have someone exercise the ABS system in coordination with a pressure bleed you will never achieve correct braking.

Finally and again my opinion the only true and effective solution to the Tahoe's (burb and Yuk) lackluster brakes is a retrofit to a Hydroboost system. I have not heard one bad review of this upgrade. These are usually found on 3/4 ton burbs and trucks and tahoes with diesel engines. It is some extra work but you wont find better braking system for your truck! This was a final mod I was working on when I sold my Tahoe.

In answer to your original question if you choose to experiment with an NBS check with Oreilys, the part number you need is: nmc2881, used in a Silverado (2000-02) 1/2 ton. You will also need a 1/2 in to 9/16 adapter for the front line of the MC. Here are 3 part numbers:AGS #BLF-26C , Edelman #258306 or Weatherhead #7912. This will allow you to go from OBS to NBS MC without having to change lines or re-do flares.

One last suggestion, take your Tahoe somewhere you can do some braking tests and do some panic stops. Measure the results before and after. You might be surprised. A firmer pedal does not necessarly mean a faster stopping truck!

Good luck!
Dan

 

[MarkD51]

Hello Dan, Thank you for your reply.

Yes, I've must've combed through over 200 responses, and comments on this topic here, and all the additional links others have provided, going into Hydroboost, and basically every other mod under the sun, like rear Discs, pads, rotors, bleeding, brake hoses, etc.

I would've thought, that like some seem to claim, that the NBS Master Cylinder retrofit is thought to be able to push a greater volume of fluid, thus a better efficiency, and more effective positive braking as a result?

I would imagine, if one spent the money, on some huge Brembo, or SSBC 13" Rotors, 4, or 6 piston front Calipers, that yes, braking performance should no doubt be much better but of course at a very high cost. I know well such large Rotors will not be compatible with stock wheels, just not enough clearance.

I'd like better brakes, but not at $3K to $4K for such.

I want to go bigger custom tires, and wheels, but right now, the most important thing to address is very bad brakes on my Tahoe.

I've previously mentioned some mods I have done, and the truck only has 39,800 on the Odo, but I of course know, mileage don't mean a thing, the truck is pushing 17 years of age, and like anything, time takes its toll.

I'll be studying some more, to decide whether such meager investments to the Brakes are a worthwhile expenditure.

Thank you very much again. Would indeed like hearing more forumite's comments on such. Mark

 

[SunlitComet]

As long as you just changed the MC and not sucked in air to the controlled abs passages any air from installing the MC will bleed right thru the abs to the wheels. If the abs cycles with air passing it to the wheels Then it will take more steps to get it out. In fact service manual says if you bench bleed the mc and are only replacing that alone then bleeding of all the brake lines in not needed. While the nbs has a firmer feel is an illusion because you are fighting the smaller wheel cylinders compared to disc brakes. If you want instant super duper response with little effort and some serious inertial force the hydro-booster with a JB8 booster and MC. with all other components being in good condition I would not put loose item in the seat and slam on the brakes. Mind you will have a higher risk of being rear ended if always waiting till the last minute to apply the brakes because the feel so right. Some vehicles can't slow at the same rate. That is why you see people steering to the side when someone slams the brakes.

 

[Nak]

What he said!

 

[nomad]

...I'd like better brakes, but not at $3K to $4K for such.

I want to go bigger custom tires, and wheels, but right now, the most important thing to address is very bad brakes on my Tahoe...
Mark

Based on what you said in your reply Hydroboost is your best option, you can easily (with a little work) track down a complete unit in a salvage yard and complete the retrofit for under $400.00 and if you go to a upull and pay much less then that.

Considering you wish to go to larger tires this will also provide the additional force needed to stop the extra kenetic energy they produce. Check with any good 4x4 center that does upgrades and they will tell you hydroboost is the only way to go with huge tires and wheels.

I recently posted with pictures exactly what you need to do a full conversion in this thread.

Keep us posted with your project!
Dan

 

[MarkD51]

Based on what you said in your reply Hydroboost is your best option, you can easily (with a little work) track down a complete unit in a salvage yard and complete the retrofit for under $400.00 and if you go to a upull and pay much less then that.

Considering you wish to go to larger tires this will also provide the additional force needed to stop the extra kenetic energy they produce. Check with any good 4x4 center that does upgrades and they will tell you hydroboost is the only way to go with huge tires and wheels.

I recently posted with pictures exactly what you need to do a full conversion in this thread.

Keep us posted with your project!
Dan

I deeply appreciate you folks advice, and help.

Re-reading all the posts again, I see you folks have given wise advice, the NBS MC will probably not be the way to go. I surely don't wish to sacrifice a firmer pedal feel, for longer stopping distances.

My brakes were actually working pretty decent with the Stillen larger Calipers, Slotted Rotors, and Stainless Braided Hoses. Then last summer getting the AC fixed, my brakes went to shit in a handbasket.

I almost ran the damn mechanic over pulling into the shop.

Something has gone bad, and I'm not sure at this point, could be a booster, could be a MC, or could be air in the system? The Stillen Calipers look to be in great shape, but are they setting up? Same with the back wheel cylinders, and I have adjusted them (I have 11" drums)

The same shop wants to charge me $75 minimum for a Bleed, and I don't know what sort of bleed they'll do? Maybe one guy in the cab, and another at the wheels, and I gather this is not optimal.

I might be willing to at least first spring for a Power Bleeder Kit, with Tank, but I am going to have to find the adapter plate that will fit onto that stupid large OBS MC rectangular Resovoir Cap?

I see Summit sells these power bleeders, anyone know which is the correct model I need?

I'd just be happy getting my brakes back to the way they used to work for the time being. Right now, I don't trust driving the truck at 30mph.