New brake lines in, bleeder questions

[HiHoeSilver]

My 2000 Z71 was drums, but it was OBS. I don't think I've seen them on an NBS.

 

[Rocket Man]

My 2000 Z71 was drums, but it was OBS. I don't think I've seen them on an NBS.

I guess that's why they list rear drums and rear discs for 2000. I didn't even realize there was a 2000 OBS. Live and learn.

 

[Randy Whistler]

Went and looked, my 2000 LS has discs on the rear as well. From what I understand, it is NBS, so that might explain something. It was very confusing when I first tried to figure it out. . . .

Now I just have to see if it's single or dual pistons, yank them off and get the new ones. Sounds pretty simple after everything I went through with the brake line!

 

[PG01]

2000 was first year of nbs except for z71, escalade, denali etc....those were still obs...im 99.99% sure of that.

 

[HiHoeSilver]

2000 was first year of nbs except for z71, escalade, denali etc....those were still obs...im 99.99% sure of that.

And the Tahoe limited.

 

[bsamole]

1999 Tahoe 4x4 8mm rear drums 10mm front disc.

 

['99_Tahoe LS 4WD - AZ]

Hey, all, I'm so sorry to jack this thread, but I have run out of places to post this and I think this might be the best place. This has to do with upgrading the rear drums on my 1999 Tahoe 2-dr 4WD to discs...a job I had done last week.

So, here is the list of the things I did, in order, to my Hoe reference to its brakes:

1. Upgraded the front discs to Powerstop with bigger rotors and calipers (2014)
2. Converted to the Hydro-boost braking system (hydraulic instead of the old vacuum) (2015)
3. Installed a rear drum to disc conversion kit (last week - July 2018)
4. Upgraded all of the old rubber brake lines to braided steel lines

Now, here is the issue I am having. The shop that installed the rear discs could not get them to bleed. They stated they would need a specific hand-tool computer to instruct the ABS system to bleed the brakes. They stated they did not think the new rear brakes were "grabbing" and it was "a hydraulic problem, not a fluid problem." So I had the truck towed to my local dealer, as I was afraid to drive it (I did get in and stepped on the brakes while the engine was running and the pedal was mushy and went close to the floorboard, and the red BRAKE light was lit on my dashboard.

So, I went to my local Chevrolet dealer and they were able to bleed the brakes. They stated there was not enough pressure/fluid going from the ABS module/EBCM to the rear calipers and there was nothing else they would or could do. They did suggest I go to a local speed shop (Lopers) to see if they would install an automatic proportioning valve to get more pressure to the rear disc brakes.

So, I went to Lopers and they said the dealer was full of shit and they would have to entirely remove the existing ABS system from my Tahoe and "re-plumb it" to the tune of about 2000 dollars. Yikes!

So, here is my question: I have to believe there is an easier fix to this than what I am hearing. For example, in 1999, Chevy had disc brakes all the way around on the OBS Suburbans and 3/4 ton and larger pick up trucks, with four-wheel ABS and I have to assume they worked fine and got pressure/fluid.

So, basically, what my system is now (with the exception of the stock EBCM and ABS module/pump) is what was in a 1999 OBS Suburban or 3/4 ton or larger pick-up truck. Is it just a matter of upgrading my EBCM and ABS module (I have a Kelsey-Hayes system) to what is in the 1999 Suburban / 3/4 ton truck? Or am I fu**ked? I need info and options, brother. Please help!!!!!

 

[CountryBoy19]

Hey, all, I'm so sorry to jack this thread, but I have run out of places to post this and I think this might be the best place. This has to do with upgrading the rear drums on my 1999 Tahoe 2-dr 4WD to discs...a job I had done last week.

So, here is the list of the things I did, in order, to my Hoe reference to its brakes:

1. Upgraded the front discs to Powerstop with bigger rotors and calipers (2014)
2. Converted to the Hydro-boost braking system (hydraulic instead of the old vacuum) (2015)
3. Installed a rear drum to disc conversion kit (last week - July 2018)
4. Upgraded all of the old rubber brake lines to braided steel lines

Now, here is the issue I am having. The shop that installed the rear discs could not get them to bleed. They stated they would need a specific hand-tool computer to instruct the ABS system to bleed the brakes. They stated they did not think the new rear brakes were "grabbing" and it was "a hydraulic problem, not a fluid problem." So I had the truck towed to my local dealer, as I was afraid to drive it (I did get in and stepped on the brakes while the engine was running and the pedal was mushy and went close to the floorboard, and the red BRAKE light was lit on my dashboard.

So, I went to my local Chevrolet dealer and they were able to bleed the brakes. They stated there was not enough pressure/fluid going from the ABS module/EBCM to the rear calipers and there was nothing else they would or could do. They did suggest I go to a local speed shop (Lopers) to see if they would install an automatic proportioning valve to get more pressure to the rear disc brakes.

So, I went to Lopers and they said the dealer was full of shit and they would have to entirely remove the existing ABS system from my Tahoe and "re-plumb it" to the tune of about 2000 dollars. Yikes!

So, here is my question: I have to believe there is an easier fix to this than what I am hearing. For example, in 1999, Chevy had disc brakes all the way around on the OBS Suburbans and 3/4 ton and larger pick up trucks, with four-wheel ABS and I have to assume they worked fine and got pressure/fluid.

So, basically, what my system is now (with the exception of the stock EBCM and ABS module/pump) is what was in a 1999 OBS Suburban or 3/4 ton or larger pick-up truck. Is it just a matter of upgrading my EBCM and ABS module (I have a Kelsey-Hayes system) to what is in the 1999 Suburban / 3/4 ton truck? Or am I fu**ked? I need info and options, brother. Please help!!!!!

Have you checked part numbers and diagram for various brake system components? IE., is your abs module the same as what is in the vehicles that came with 4 wheel discs?

 

[Randy Whistler]

As mentioned along the way in this thread, I had to replace my line from the ABS module under the driver side, and had to replace both calipers on the rear axle - neither bleeder would unscrew - break, yes, but not unscrew. I should note that, while running the new brake line, the ABS and master cylinder both did not hold their water, and had to be refilled when the line was in.

Once the calipers were replaced, bleeding was not a major issue. No reengineering, etc. Since yours is somewhat modified, this may not help much, but bleeding the lines and calipers weren't anything special, exciting or unusual.

I know this may not help any, but as long as the lines were in good shape, I've never had any major brake bleeding issues on any vehicle.

 

['99_Tahoe LS 4WD - AZ]

As mentioned along the way in this thread, I had to replace my line from the ABS module under the driver side, and had to replace both calipers on the rear axle - neither bleeder would unscrew - break, yes, but not unscrew. I should note that, while running the new brake line, the ABS and master cylinder both did not hold their water, and had to be refilled when the line was in.

Once the calipers were replaced, bleeding was not a major issue. No reengineering, etc. Since yours is somewhat modified, this may not help much, but bleeding the lines and calipers weren't anything special, exciting or unusual.

I know this may not help any, but as long as the lines were in good shape, I've never had any major brake bleeding issues on any vehicle.

Thanks very much for this, Randy....very helpful! I now have the correct ABS module, MC and reservoir as well as the right hydrobooster and hydrobooster pedal ready for install. I'm going to have them installed next week and I think this should do the trick!