kylenautique
I'm Awesome
Hi Everyone! This is my first post, but I have been wrenching on trucks since I was in my early teens. So, you have a GMT 400 truck, but the brakes are somewhat crummy... You have some options. This is what I did to make my 98 k1500 truck stop amazing.
First thing... Make sure all the little things are set up properly. Replace your pads with good pads. I use Powerstop z36 brake pads. Make sure your rear brakes are in good condition and adjusted properly. Its not a bad idea to adjust them every time you change your oil. Stainless Steel Brake lines make a difference! Replace the worn out stock rubber lines. These trucks are getting old, so its worth the money.
Second Step... The master cylinder. If you replace it, you MUST bench bleed it. Some of these trucks can be upgraded to the NBS master cylinder. Its very simple to do and requires one $6 adapter from autozone. Google the GMT400 NBS master cylinder upgrade. My truck however cannot use this. I have the JB6 brake code with the 14 bolt rear end. I was not able to get good pressure.. I think this mod only works with JB5 brake codes.
Third Step... The ABS unit. There is lot controversy on this. Trucks Prior to 95 have a rear only ABS unit. When they fail it can mimic a bad master cylinder. The simple way to resolve this is to remove it and just connect the lines together with a combination valve or adjustable proportion valve. 95 and up is a totally different beast. You have two parts to this system. The built in combination valve and the 4wheel ABS unit. You pretty much need a GM Tech2 scanner or Snapon scanner to bleed the system properly. If the ABS is failing, you can pull the fuse and it becomes a regular combination valve. In my case on my 98, the combination valve started sticking so my hydraulic brake side of the system was problem. No one really services these units and there are no parts available. The two options are, replace it with one from the junk yard, or delete it completely. I opted to delete it. Use this video for the fittings needed
You simply T together the front lines and install a adjustable proportion valve for the Rears. You will be amazed at actually how awesome your truck stops. These trucks have amazing brakes, but I can almost guarantee if you did my Steps 1 and 2, if you still have issues, its going to be the ABS unit. They get gummed up from old Brake fluid. Remember these trucks are getting old, so some systems are going to fail. For me, I have driven many older vehicls without ABS, so I'm not a driver that needs it. If you are 17 years old and reading this, you may want to find a replacement ABS unit. All depends on drivers skill ABS is a good system, but I always find my self disabling it. If you rely on ABS and are not used to driving a truck without it, I don't recommend it
4th Step... You can install a hydrobost unit. Google this as well. To sum it up, 94 and older use a different pedal and hydroboost compared to 95 and up. Make sure you match this up, or you will be drilling your pedal. Hydroboost provides over twice the clamping force of a vacuum booster. For my 98, I don't feel I need this. Keep in mind hydroboost is amazing, but if your power steering pump fails or you get a leak while driving... you have 3 brake presses before you loose all braking ability.
So that's the trick everyone. These trucks can stop great. I have a 6" lift and 33" tires. I stop on a dime now. My next modification is to replace the rear drums with disc brakes.
First thing... Make sure all the little things are set up properly. Replace your pads with good pads. I use Powerstop z36 brake pads. Make sure your rear brakes are in good condition and adjusted properly. Its not a bad idea to adjust them every time you change your oil. Stainless Steel Brake lines make a difference! Replace the worn out stock rubber lines. These trucks are getting old, so its worth the money.
Second Step... The master cylinder. If you replace it, you MUST bench bleed it. Some of these trucks can be upgraded to the NBS master cylinder. Its very simple to do and requires one $6 adapter from autozone. Google the GMT400 NBS master cylinder upgrade. My truck however cannot use this. I have the JB6 brake code with the 14 bolt rear end. I was not able to get good pressure.. I think this mod only works with JB5 brake codes.
Third Step... The ABS unit. There is lot controversy on this. Trucks Prior to 95 have a rear only ABS unit. When they fail it can mimic a bad master cylinder. The simple way to resolve this is to remove it and just connect the lines together with a combination valve or adjustable proportion valve. 95 and up is a totally different beast. You have two parts to this system. The built in combination valve and the 4wheel ABS unit. You pretty much need a GM Tech2 scanner or Snapon scanner to bleed the system properly. If the ABS is failing, you can pull the fuse and it becomes a regular combination valve. In my case on my 98, the combination valve started sticking so my hydraulic brake side of the system was problem. No one really services these units and there are no parts available. The two options are, replace it with one from the junk yard, or delete it completely. I opted to delete it. Use this video for the fittings needed
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You simply T together the front lines and install a adjustable proportion valve for the Rears. You will be amazed at actually how awesome your truck stops. These trucks have amazing brakes, but I can almost guarantee if you did my Steps 1 and 2, if you still have issues, its going to be the ABS unit. They get gummed up from old Brake fluid. Remember these trucks are getting old, so some systems are going to fail. For me, I have driven many older vehicls without ABS, so I'm not a driver that needs it. If you are 17 years old and reading this, you may want to find a replacement ABS unit. All depends on drivers skill ABS is a good system, but I always find my self disabling it. If you rely on ABS and are not used to driving a truck without it, I don't recommend it
4th Step... You can install a hydrobost unit. Google this as well. To sum it up, 94 and older use a different pedal and hydroboost compared to 95 and up. Make sure you match this up, or you will be drilling your pedal. Hydroboost provides over twice the clamping force of a vacuum booster. For my 98, I don't feel I need this. Keep in mind hydroboost is amazing, but if your power steering pump fails or you get a leak while driving... you have 3 brake presses before you loose all braking ability.
So that's the trick everyone. These trucks can stop great. I have a 6" lift and 33" tires. I stop on a dime now. My next modification is to replace the rear drums with disc brakes.