Do these brakes need to be computer bleed? cant get a great pedal..the pedal goes low and the abs kicks on..got some air out of right front then they were better...now they seem to be low again.

Then you still have air in the system. Did you do any work to it recently?

But yes, the ABS pumps need to be turned on via a high end scantool such as the SnapOn'* or GM Tech2'* and activate the bleed procedure.

Or, if you have access to a gravel parking lot, you can get some speed and slam on the brakes to activate the pump. This takes a couple of tries, rebleed, rebrake etc.

These trucks are known to have a low pedal feel. Abs activation could be a wheel speed sensor issue causing the abs to activate. A good way of telling for air in the system is to pump the brake pedal and if it always fall to the floor at all times, its a sure bet.

the kelsey hayes are just incredibly hard to get the air out of. you can use a scanner if you have it but you can get a decent petal, unless you have issues with the master, you have to do it like this;

take apart the rear drums and free and lube the adjusters then adjust them out so the drums just barley fit,

turn the key on, then bleed in the normal manner,

take it out on the road and jam on the brakes so abs activates a few times. repeat step 2,

if you dont have decent brakes repeat both. it wont be perfect or like it was at this point, you have to drive it a bit to allow the bubbles to work out and the rear adjusters to work in. it took a few weeks of non daily use before mine felt normal after i replaced the lines and master cyl

they have been bled many times..still low..how does slamming on the brakes activate the pumps and then what?

Slamming on the brakes will cause the ABS to activate. Once it activates it will move air through the system. Then you can re-bleed and get more air out. You may have to bleed it several times and EACH wheel. Make sure you don't have a brake fluid leak anywhere.

It is possible that you need a new master cylinder...

ok I will try it.

you have to have the key on too. sometimes people do it with the engine on, but i never needed to go that far