The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1988 - 1998 GMT400 Chevy & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 03-05-2018, 08:13 PM   #1
speedygonzales
Registered User
 
speedygonzales's Avatar
 
Join Date: Jan 2006
Location: Smithfield, VA
Posts: 1,359
First hand experience with changing to the NBS MC BUSTED

Yes folks I started that post back in 2013. I thought at the time I was onto something. I wasn't the first to do the MC change.

Let me cut to the chase first before I give you a little back story so if you don't need the back story you don't have read it.

You only need to bleed the ABS system.

TO DO THIS:
Bleed the brakes like normal.
Do or have done the ABS Automated Bleed Procedure
Bleed the brakes one more time like normal.

When DONE, the brakes are like new, better than anything else.

Back story.
So after doing numerous bleeds (the standard way) using new fluid and being sure to remove all the old fluid.

Changed the Master Cylinder (MC) to the New Body Style (NBS) AKA GMT800. and thought wow I'm on to something. Changed the front calipers to 2 piston style and the rotors to slotted. Eh was OK.

Oh yeah changed the hoses to braided style. NOPE none of this compares to running the automatic bleed procedure. I didn't even do it right and it still was like my old brakes were back.

Summer of 2017 I bought my son a 1984 GMC K1500. I noticed his MC was the exact same one that came on our trucks from the factory. BUT his truck would snap your neck if you pressed the brake too hard.

Read that again, the 1984 had the same MC as our trucks. So what is the difference?

I was convinced it was our ABS. But how? It had to be causing a restriction. His works fine, ours seems like crap. That has to be it. I wanted to make short intermediate lines to test it by jumping around the ABS module but you know how that goes. Life goes on and good intentions.

So fast forward to a few days ago and I'm chiming in a brake problem and guy there says you can't just bleed a problem away. You have to get the "procedure" done.

It doesn't seem to make sense to anyone else either but there are post after post after post stating if you don't do it you don't get your brakes back. Several others said they had it done and damn if they don't have their brakes back to normal.

I told a guy I doubt it but I would try it. So I pulled out the Solus and checked and sure enough there it is in front of God and everybody. The Automatic Brake Bleed. Never thought to look for it cause I was sure I didn't need it. How could that have an effect on our normal brake operation???

Now I did not do the actual correct operation YET. By that I mean I did not bleed the brakes first, run the ABB and then bleed again.

I ONLY RAN THE ABB. I did not bleed them first and after, YET, but holy crap what a difference. The old brakes are back.

So I got the old brakes back and I haven't even done the correct procedure.

So here's what happened during the procedure. You have the vehicle running and your foot on the brake pressing it. It does something to cause the brake pedal to go all the way down. Then it works it's way back up and it goes down and up and does this a few times and then the pedal ends up like it started. Took it for a ride and holy crap.

IN the next few days, cause of weather in VA, I'll do a full bleed, run the ABB again and bleed once more and I'm done chasing the problem down.

For what it's worth I did NOT discover the solution, I'm merely bringing it to everyone's attention.

If you have to have this done at a service center of some sort, ask the tech if this has been their experience. It sure would be nice to put this issue to bed once and for all.

Good luck to you all. Oh and if you're in the Hampton Roads area, you can stop buy any time I'm home for help. Not after 9 PM though.
__________________
99 Z71 (98 body style)
Pride and joy
speedygonzales is offline   Reply With Quote
Old 03-05-2018, 08:39 PM   #2
Tom
driving is in my blood
 
Tom's Avatar
 
Join Date: Dec 1999
Location: Mesa AZ
Posts: 4,790
Re: First hand experience with changing to the NBS MC BUSTED

Congrats, but you single experience isn't enough to be conclusive. I've done the scan tool bleed. It didn't change anything. The NBS master did.
__________________
-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: stock
-CBR600F4i, CBR600RR, CBR1000RR, and standup skis
DISCLAIMER: I cant spell for the life of me.
Tom is offline   Reply With Quote
Old 03-06-2018, 10:55 AM   #3
speedygonzales
Registered User
 
speedygonzales's Avatar
 
Join Date: Jan 2006
Location: Smithfield, VA
Posts: 1,359
Appreciate the heads up.... I think.

Quote:
Originally Posted by Tom View Post
Congrats, but you single experience isn't enough to be conclusive. I've done the scan tool bleed. It didn't change anything. The NBS master did.
Quote:
Originally Posted by speedygonzales View Post
So fast forward to a few days ago and I'm chiming in a brake problem and guy there says you can't just bleed a problem away. You have to get the "procedure" done.

It doesn't seem to make sense to anyone else either but there are post after post after post stating if you don't do it you don't get your brakes back. Several others said they had it done and damn if they don't have their brakes back to normal.
Sorry but I think you have it backwards. Your single experience isn't conclusive. Perhaps you missed the part where I said I read SEVERAL people have done this.

And I don't recall you chiming in with the fact that this didn't work for you before now on the original NBS MC thread or did I miss something?

In addition to that, I haven't read anyone that said the NBS MC made the brakes the best they could be. Better yeah, great not so much.

I'm sticking with the fact that not only mine but SEVERAL others have brought theirs back with no parts change by doing this.

We might agree to disagree and that's fine. That's what the BB is all about. But everyone has to agree that when troubleshooting any problem. The least expensive option should always be explored first. For most people that's going to be a "bleed" then an "automatic bleed procedure" then a last "bleed".

My evidence concludes your experience is the exception not the rule.
__________________
99 Z71 (98 body style)
Pride and joy
speedygonzales is offline   Reply With Quote
Old 03-06-2018, 01:10 PM   #4
Keith Seymore
Senior Member
 
Keith Seymore's Avatar
 
Join Date: May 2009
Location: Motor City
Posts: 7,416
Re: First hand experience with changing to the NBS MC BUSTED

Quote:
Originally Posted by speedygonzales View Post

Summer of 2017 I bought my son a 1984 GMC K1500. I noticed his MC was the exact same one that came on our trucks from the factory. BUT his truck would snap your neck if you pressed the brake too hard.
When you say "...exact same one that came on our trucks..." do you mean by part number? or do you mean it visually appeared to be the same?

K
__________________
Chevrolet Flint Assembly
1979-1986
GM Full Size Truck Engineering
1986 - Present
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/
Keith Seymore is offline   Reply With Quote
Old 03-07-2018, 03:40 PM   #5
83GMCK2500
Registered User
 
Join Date: Sep 2009
Location: Western WA
Posts: 1,455
Re: First hand experience with changing to the NBS MC BUSTED

Quote:
Originally Posted by Keith Seymore View Post
When you say "...exact same one that came on our trucks..." do you mean by part number? or do you mean it visually appeared to be the same?

K
I'm curious too, I know that visually the MC on my '83 K20 looks like the one on my '96 K3500 & '97 K1500...it was my understanding that the old ones have a stepped bore and the ones on the ABS trucks had a continuous bore.
__________________
Devin

1983 GMC High Sierra 2500, 4x4, RC/LB, 400 S.B., SM-465, NP-208, Corporate 10 bolt & 9.5" 14 bolt
1996 GMC Sierra SLE 3500 DRW, 4x4, EC/LB, Vortec 454, NV-4500, BW-4401, AAM 925 & AAM 1050

My Introduction with my '83s History
New Daily, the '96
83GMCK2500 is online now   Reply With Quote
Old 03-07-2018, 07:34 PM   #6
Tom
driving is in my blood
 
Tom's Avatar
 
Join Date: Dec 1999
Location: Mesa AZ
Posts: 4,790
Re: Appreciate the heads up.... I think.

Quote:
Originally Posted by speedygonzales View Post
Sorry but I think you have it backwards. Your single experience isn't conclusive. Perhaps you missed the part where I said I read SEVERAL people have done this.

And I don't recall you chiming in with the fact that this didn't work for you before now on the original NBS MC thread or did I miss something?

In addition to that, I haven't read anyone that said the NBS MC made the brakes the best they could be. Better yeah, great not so much.

I'm sticking with the fact that not only mine but SEVERAL others have brought theirs back with no parts change by doing this.

We might agree to disagree and that's fine. That's what the BB is all about. But everyone has to agree that when troubleshooting any problem. The least expensive option should always be explored first. For most people that's going to be a "bleed" then an "automatic bleed procedure" then a last "bleed".

My evidence concludes your experience is the exception not the rule.
Basically, your finally accepting that you should a bleed as its supposed to be done before swapping parts. Most people, myself included, do the procedures correctly before changing out parts. That's my point. No, my single experience is indeed not a conclusion. I did not state anywhere that you cannot change brake pedal feel via proper bleeding procedures. I am merely stating that a single persons results, mine, yours, joe bob's, is not the end all to a particular problem. Even with a properly bleed system, I still felt the feedback wasn't where I liked it, I'm sure there will be others who feel the same.
__________________
-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: stock
-CBR600F4i, CBR600RR, CBR1000RR, and standup skis
DISCLAIMER: I cant spell for the life of me.
Tom is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 12:41 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.
Copyright 1997-2013 67-72chevytrucks.com