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#76 |
driving is in my blood
Join Date: Dec 1999
Location: Mesa AZ
Posts: 5,726
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Re: First hand experience with changing to the NBS master cylinder WOW!
I'm confused. You didn't have less braking power with the original booster and NBS master. You just needed more pedal effort, which is the entire point of the swap. You changed the master cylinder to get a firmer pedal, then changed the booster style to get a less firm pedal? Sounds like you just needed a correctly functioning OBS master and 10.75" booster to begin with... Your diaphram research and pictures are excellent btw!
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-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me. |
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#77 | |
Registered User
Join Date: Apr 2014
Location: Colorado
Posts: 25
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Re: First hand experience with changing to the NBS master cylinder WOW!
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Finally, good brakes!!! ![]() |
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#78 | |
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![]() Join Date: Aug 2011
Location: Vancouver, WA.
Posts: 64
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Re: First hand experience with changing to the NBS master cylinder WOW!
Quote:
I don't know for sure if I had a correctly functioning OBS master and booster. No leaks, tested ok. I do know that the truck didn't brake very well at all. From what I read that is a common complaint of owners of these trucks. I think it's a fair assumption that the standard brakes on these trucks were not adequate for alot of owners. There were 3 different brake options on 1/2 ton trucks. Good-better-best. Good wasn't very good IMHO.
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'88 K1500 Scottsdale 5.7 TBI, 5spd MG5 |
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#79 |
Registered User
Join Date: Apr 2014
Location: Colorado
Posts: 25
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Re: First hand experience with changing to the NBS master cylinder WOW!
Red, how much thicker was the dual diaphragm booster? I was wondering how much I'd have to move the brake lines where they attach to the MC...
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#80 |
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![]() Join Date: Aug 2011
Location: Vancouver, WA.
Posts: 64
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Re: First hand experience with changing to the NBS master cylinder WOW!
I didn't have the presence of mind to measure but if memory serves about 2". There was plenty of slack in the brake lines coming up from the frame to make the connections. I imagine factory used same lines irregardless of the booster option.
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'88 K1500 Scottsdale 5.7 TBI, 5spd MG5 |
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#81 | |
driving is in my blood
Join Date: Dec 1999
Location: Mesa AZ
Posts: 5,726
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Re: First hand experience with changing to the NBS master cylinder WOW!
Quote:
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-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me. |
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#82 | ||
driving is in my blood
Join Date: Dec 1999
Location: Mesa AZ
Posts: 5,726
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Re: First hand experience with changing to the NBS master cylinder WOW!
Quote:
![]() Quote:
__________________
-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me. |
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#83 |
Registered User
Join Date: Apr 2014
Location: Colorado
Posts: 25
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4wd. Not just helped, this was like my moby dick. I've had this truck since new and really enjoyed everything else about it but was always disappointed with the brakes / options for improvement available. I was to the point that I didn't even want my family in the truck on the highway, i was afraid of a collision.
BTW, Just picked up some stuff for the rear brakes, hopefully it'll be even a little mo' betta! ![]() |
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#84 |
Registered User
Join Date: Jan 2006
Location: Smithfield, VA
Posts: 1,501
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So what type do I have?
Ok I have JB5 system and lookup says they are 6400 Lb.
Here's a picture http://i1371.photobucket.com/albums/...g?t=1403961476 Only thing I see is the "DA" sticker. So what do I have? And how do you figure it out? I didn't see anything that explains the types of diaphragms. How does the types relate to the RPO code? I see JB8 says 10000 Lb ![]() I found this on a bulletin board JB5= front disc 11.86X1.29 rear drum 11.15X2.75 Vacuum-Double Diaphragm JB7= front disc 12.50X1.54 rear drum 13.00X2.50 Vacuum-Double Diaphragm JB8= front disc 12.50X1.54 rear drum 13.00X3.50 Hydraulic-Hydro-Boost But how do you get part numbers for these boosters. Then there is this: http://www.oreillyauto.com/site/c/de...1305&ppt=C0066 It says it's 10.75" and used for JB5,6&7???? I don't get it. Do I want the one that is 13" x 2.5? Do you look for the booster from a 1 ton truck? Last edited by speedygonzales; 06-28-2014 at 09:45 AM. |
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#85 |
Registered User
Join Date: Apr 2014
Location: Colorado
Posts: 25
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Re: First hand experience with changing to the NBS master cylinder WOW!
Hey Speedy
I have JB6 brakes and believe I have the single diaphragm booster...With an HA sticker on it Vacuum-boosted: JB5 = Power Brakes, Disc/Drum, 6,400 lb JB6 = Power Brakes, Disc/Drum, 7,200 lb JB7 = Power Brakes, Disc/Drum, 8,400 lb JB8 = Power Brakes, Disc/Drum, 10,000 lb Hyrdaulic-boosted: JD5 = Dual Power Brakes, Disc/Drum, 6,400 lb JD6 = Hydraulic Power Brakes, Disc/Drum, 7,200 lb JD7 = Hydraulic Power Brakes, Disc/Drum, 8,400 lb JF9 = Hydraulic Power Brakes, 4-Wheel Discs I believe the JB7 called for the larger DD booster you linked to. There is also a SMALLER DD booster available... Is that what you have on your JB5's? |
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#86 | |
Registered User
Join Date: Jan 2006
Location: Smithfield, VA
Posts: 1,501
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Haven't got a clue
Quote:
Now above you say JB8 was vacuum but all the information I saw was it was Hydro. If it is vacuum, I want it. |
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#87 |
Registered User
Join Date: Apr 2014
Location: Colorado
Posts: 25
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Re: First hand experience with changing to the NBS master cylinder WOW!
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#88 | |
Registered User
Join Date: Apr 2014
Location: Colorado
Posts: 25
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Re: Haven't got a clue
Quote:
JB8 76 88 BRAKE SYSTEM,HYD PWR DISC/DRUM So they were hydro-boost systems installed from 1976-1988. Sorry about that other RPO lookup, I got that from another post online. |
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#89 |
driving is in my blood
Join Date: Dec 1999
Location: Mesa AZ
Posts: 5,726
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Re: First hand experience with changing to the NBS master cylinder WOW!
Yes all JB8's were hydroboost. I have the JB5 and have the dual diaphram stamped 'HA' like rockauto said I would. Not sure where the single diaphram is used....
__________________
-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me. |
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#90 |
Registered User
Join Date: Jan 2006
Location: Smithfield, VA
Posts: 1,501
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Re: First hand experience with changing to the NBS master cylinder WOW!
So is the JB7 really 13" and if so, how do I find it?
Or should I just try making a slightly longer intermediate rod? |
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#91 |
Registered User
![]() Join Date: Jul 2006
Location: Ozark, MO
Posts: 4,887
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Re: First hand experience with changing to the NBS master cylinder WOW!
Did the MC upgrade, and bled the whole system. Pedal feels great, although overall braking effectiveness is pretty much the same. I would like to add the dual-diaphram booster, 3/4 ton calipers and Powerstop drilled and slotted rotors.
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'20 Silverado Trail Boss ~ '17 Tahoe ~ '79 K15 Sierra Grande ~ '76 Blazer 2wd ~ '71 Cheyenne swb ~ '55 Pontiac Safari ~'50 3100 bagged ~ '80 Wife ~ Late model kids
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#92 |
Registered User
Join Date: Apr 2014
Location: Colorado
Posts: 25
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Re: First hand experience with changing to the NBS master cylinder WOW!
Upgrading from a single diaphragm booster to a DD should make a noticeable difference. The 3/4 ton calipers should take advantage of your new MC as well. Just remember the 3/4 ton pads will rub your rotor hat, so either use 1/2 ton pads or grind down the metal backing plate on the 3/4 on pads.
I liked my powerslot rotors (not drilled though), hope they treat you well! |
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#93 |
Registered User
Join Date: Apr 2014
Location: Colorado
Posts: 25
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Re: First hand experience with changing to the NBS master cylinder WOW!
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#94 |
driving is in my blood
Join Date: Dec 1999
Location: Mesa AZ
Posts: 5,726
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Re: First hand experience with changing to the NBS master cylinder WOW!
I've had a couple sets of 3/4ton pads on my 98 that also has the larger piston 3/4ton calipers and 1/2ton rotors, never had a rubbing issue.
__________________
-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me. |
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#95 |
Registered User
Join Date: Jan 2006
Location: Smithfield, VA
Posts: 1,501
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Re: First hand experience with changing to the NBS master cylinder WOW!
Nope never found anything
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#96 |
Registered User
Join Date: Feb 2013
Location: NC
Posts: 37
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Re: First hand experience with changing to the NBS master cylinder WOW!
Just did this on my truck and the results were great. After I did it though, I was doing some reading online and the "store bought" version of this upgrade from SSBC shows the adapter going in the rear port and reversing the brake lines.
http://www.summitracing.com/parts/ssb-a0463 instructions... http://ssbrakes.com/attachment/63706...ction%20Manual Any ideas? |
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#97 |
Registered User
Join Date: Apr 2014
Location: Colorado
Posts: 25
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Re: First hand experience with changing to the NBS master cylinder WOW!
You may be referring to the design change on the NBS brake circuits being flipped F/R?
With our trucks using the step bore master the front circuit had to use the forward portion of the cylinder to drill the stepped bore ( can't put a bigger bore bit thru a smaller bore hole) Since the nbs uses the same bore size for both circuits, the engineers chose to reverse the layout, but they should operate identically. |
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#98 |
Registered User
Join Date: Apr 2014
Location: Colorado
Posts: 25
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Re: First hand experience with changing to the NBS master cylinder WOW!
Hey Speedy,
Since we dusted off this thread I thought I'd mention that the nnbs trucks added an electric vacuum pump to the brake systems. I plumbed one up to see if i could feel any difference... |
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#99 |
Registered User
Join Date: May 2009
Location: Motor City
Posts: 9,199
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Re: First hand experience with changing to the NBS master cylinder WOW!
I apologize for not thinking of this sooner: I have the brake system release charts from the brake engineer for the '74 and '87 trucks C/K/R/V squarebody versions.
While not totally germaine (I do not have the corresponding GMT400 versions) it will give you an idea of the proliferation and the way the components are structured and named (by part number and broadcast code). I don't see the "DA" coded booster on here but you can imagine where it would go. One of the ways you would find the corresponding part number for the "DA" booster would be finding a chart like this and working backwards. For your entertainment: ![]() ![]() ![]() ![]() ![]() ![]()
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Chevrolet Flint Assembly 1979-1986 GM Full Size Truck Engineering 1986 - 2019 Intro from an Old Assembly Guy: http://67-72chevytrucks.com/vboard/s...d.php?t=342926 My Pontiac story: http://forums.maxperformanceinc.com/...d.php?t=560524 Chevelle intro: http://www.superchevy.com/features/s...hevy-chevelle/ |
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#100 |
Registered User
Join Date: Apr 2014
Location: Colorado
Posts: 25
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Re: First hand experience with changing to the NBS master cylinder WOW!
Thanks, that's pretty sweet. Wish we had them for the 400/800's !
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1988-1999, brakes, mushy, obs |
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