Confused about brake upgrades for 93 K1500

[1998_K1500_Sub]

can bypassing my ABS help with pedal?

On my 1998, I've got (what I think is) fantastic pedal feel, with ABS still in the system.

YMMV. It may depend on the model year, IIRC there were different ABS units used through the GMT400 run. Of course it depends on the condition of the brake system, proper matching of components (e.g., quick-take-up MCs matched with low-drag calipers), proper bleeding of the ABS / lines / etc.,... I'm just repeating what's already known.

@Schurkey comes to mind when I think of ABS, perhaps he'll comment.

 

[1994rcsbLS]

On my 1998, I've got (what I think is) fantastic pedal feel, with ABS still in the system.

YMMV. It may depend on the model year, IIRC there were different ABS units used through the GMT400 run. Of course it depends on the condition of the brake system, proper matching of components (e.g., quick-take-up MCs matched with low-drag calipers), proper bleeding of the ABS / lines / etc.,... I'm just repeating what's already known.

@Schurkey comes to mind when I think of ABS, perhaps he'll comment.

thanks! for what its worth, i dont have stock dash setup. so no lights would be operating and i dont mind at all. truck isnt daily driven. doesnt need inspections, so if i can get away with deleting ( if worth it and helps brake better, im all in ) lol

 

[HotWheelsBurban]

On my 1998, I've got (what I think is) fantastic pedal feel, with ABS still in the system.

YMMV. It may depend on the model year, IIRC there were different ABS units used through the GMT400 run. Of course it depends on the condition of the brake system, proper matching of components (e.g., quick-take-up MCs matched with low-drag calipers), proper bleeding of the ABS / lines / etc.,... I'm just repeating what's already known.

@Schurkey comes to mind when I think of ABS, perhaps he'll comment.

Burbs got better brakes than the 1500 pickups did though. Only 3 times I had problems with the brakes on the Burb not working well. When the master cylinder was bad, when we first got it, got that fixed and new wheel cylinders and that was back to normal. When the brake hose collapsed and locked the caliper up, replaced hoses, calipers and pads, back to normal. And the brakes on the Burb actually worked fine last August when that Hyundai pulled out in front of us; just that she was too close to avoid hitting! BTW she admitted fault and we did have the green light and right of way.

 

[Schurkey]

I have a JB5 system, after reading this( thankfully ) im gonna hold off on doing the nbs swap. I just got my ford 9" setup with disk brakes and stainless lines. going to get that in and re visit. question though....
can bypassing my ABS help with pedal?

Only if there's something wrong with the ABS. "Something wrong" could include actual failures such as stuck solenoid valves, or it could be as simple as air trapped in the system because it's never been bled with a scan tool since the truck was built.

It's nuts to disconnect the ABS "just because". FIX the ABS, if in fact there's something wrong with it...and we're not even sure of that at this point.

First Guess: What's wrong with the pedal is a combination of the hateful 254mm rear drums which you're getting rid of, and--maybe--master cylinder/sticky calipers.

 

[1994rcsbLS]

Only if there's something wrong with the ABS. "Something wrong" could include actual failures such as stuck solenoid valves, or it could be as simple as air trapped in the system because it's never been bled with a scan tool since the truck was built.

It's nuts to disconnect the ABS "just because". FIX the ABS, if in fact there's something wrong with it...and we're not even sure of that at this point.

First Guess: What's wrong with the pedal is a combination of the hateful 254mm rear drums which you're getting rid of, and--maybe--master cylinder/sticky calipers.

I dont even know if it works at all. i just have the super spongy brake pedal. and on a truck that has a lot of go go juice i dont like not being able to stop if a dummy pulls out in front

 

[Schurkey]

BLEED THE BRAKES including the ABS unit USING A SCAN TOOL to activate the ABS valves, thereby removing air from the ABS unit itself. Use the real-live instructions from the service manual. This will amount to a total fluid flush, 'cause you're gonna run LOTS of fluid through the system. Be prepared. Don't half-ass this.

Adjust the rear brakes.

See what happens.

What ABS unit is on that truck, anyway?

 

[pressureangle]

So, continuing on; '94 K2500 diesel with JD6 brakes. I'm not unhappy with them, factory hydroboost; I'll rarely tow and nothing heavier than a motorcycle trailer. Still, I have 18" wheels and 33" tires- the rotors appear very small, this is my first 6-lug truck. It isn't perfectly clear but is it as simple as ordering JD7 calipers for the front to improve the system? I've rebuilt the rears, with 'stock' cylinders. Is there an 'easy' rotor diameter upgrade? (not asking 'cheap' just easy).

 

[Schurkey]

So, continuing on; '94 K2500 diesel with JD6 brakes... ...It isn't perfectly clear but is it as simple as ordering JD7 calipers for the front to improve the system?

The JD7 calipers have larger pistons...which is good. But the JD6 calipers are low-drag which requires the Quick Take-Up master cylinder. You would not need--and probably should not continue to use--the QTU JD6 master.

Seems to me there's issues with the JD7 pads grinding on the rotor. I don't remember details. Maybe I'm hallucinating.

I'm guessing you'd need a larger-diameter-bore master from a JD7 truck, and then larger-diameter rear wheel cylinders to keep the brakes balanced front-rear.

I upgraded my '88 K1500 from JN3 to JB6, but that's all standard GM parts intended to go together. Using JD7 calipers on small-diameter rotors with 11.x drums in back is something GM didn't do. At least, I don't know about any such application. "Real" JD7 had 12.5" rotors and 13" rear drums. So you're kinda on-your-own for figuring out how to keep the system balanced.

I've rebuilt the rears, with 'stock' cylinders. Is there an 'easy' rotor diameter upgrade? (not asking 'cheap' just easy).

Not that I know of. Maybe someone else has ideas.

I'm thinking that you'd maybe convert to the GMT800 front discs, which requires some ball-joint shenanigans. Not "easy". Might be "cheap" if you grab all the needed parts from the Treasure Yard.

 

[pressureangle]

The JD7 calipers have larger pistons...which is good. But the JD6 calipers are low-drag which requires the Quick Take-Up master cylinder. You would not need--and probably should not continue to use--the QTU JD6 master.

Seems to me there's issues with the JD7 pads grinding on the rotor. I don't remember details. Maybe I'm hallucinating.

I'm guessing you'd need a larger-diameter-bore master from a JD7 truck, and then larger-diameter rear wheel cylinders to keep the brakes balanced front-rear.

I upgraded my '88 K1500 from JN3 to JB6, but that's all standard GM parts intended to go together. Using JD7 calipers on small-diameter rotors with 11.x drums in back is something GM didn't do. At least, I don't know about any such application. "Real" JD7 had 12.5" rotors and 13" rear drums. So you're kinda on-your-own for figuring out how to keep the system balanced.


Not that I know of. Maybe someone else has ideas.

I'm thinking that you'd maybe convert to the GMT800 front discs, which requires some ball-joint shenanigans. Not "easy". Might be "cheap" if you grab all the needed parts from the Treasure Yard.

Hmm. I just had the wheels off for new shocks, and noticed the brake pads touch the rotor hat just enough to keep the rust fresh. I wonder if this has already happened.
I'm keeping an eye out for a G80 rear axle, seems the FF are easier to find than the SF, though again I'm sort of navel-gazing here not really needing more brakes (but I also believe you can never have too much brakes) I see GMT800 brakes for sale in the forum, what's the ball joint story? I have what I need to ream the taper myself- can the control arms be swapped, or ball joints changed?

 

[kylenautique]

My 98 silverado 1500, I have a 2500/3500 hydroboost and master cylinder, 3500 front calipers, and the GMT800 10 bolt rear disc brakes on my stock 14 bolt rear end. I've also deleted the ABS only because it failed. The front brakes are tied together with a T, and the rear brakes have a wilwood adjustable proportioning valve. 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. The most expensive part was the rear axle spacers to adapt the GMT800 disc brake backing plates.