2nd gen brake master cylinder

[KidVermicious]

2nd gen guys - what's the difference between a master cylinder from a truck with ABS and a truck without ABS? And if I'm picking through a yard with no internet, how do I quickly identify trucks with ABS and trucks without?

 

[SV_Dude]

According to the mc's available on advanceauto.com, they don't specify with or w/o abs. I could be wrong but I think that the ABS is transparent to the mc. I think that the ABS is controlled by a computer or some other hydro module that is in between the calipers and the mc.

 

[KidVermicious]

According to the mc's available on advanceauto.com, they don't specify with or w/o abs. I could be wrong but I think that the ABS is transparent to the mc. I think that the ABS is controlled by a computer or some other hydro module that is in between the calipers and the mc.

That would be cool if that was the case. They're listed on Rockauto as with or without ABS, but they're all generic pics that tell me NUTHINK.

 

[helo-mech]

Yeah the ones I have ever messed with have the ABS module aft of the MS. The MS lines would run to a seperate housing controlled by the ABS computer.

I'm sure there are some that are integrated but I have never seen them.

 

[SV_Dude]

I'm pretty sure that the ABS is controlled by some component after the mc. I think you're safe in finding any 2nd gen mc.

 

[KidVermicious]

Yeah the ones I have ever messed with have the ABS module aft of the MS. The MS lines would run to a seperate housing controlled by the ABS computer.

I'm sure there are some that are integrated but I have never seen them.

I'm pretty sure that the ABS is controlled by some component after the mc. I think you're safe in finding any 2nd gen mc.

So there's not a separate line running to the ABS module?

 

[SV_Dude]

Once again, I could be wrong... but... In the earlier ABS vehicles I think that the brake lines coming from the mc all went to an abs module, then to the calipers.

 

[KidVermicious]

Schweet. That'll make scrounging much easier.

 

[fourwd1]

The early ABS uses a separate actuator and actually uses pressure from the Power Steering system. The ABS sensor is mounted on the rear diff.

 

[SV_Dude]

The early ABS uses a separate actuator and actually uses pressure from the Power Steering system. The ABS sensor is mounted on the rear diff.

So how was the ABS integrated with the braking system?

 

[KidVermicious]

The early ABS uses a separate actuator and actually uses pressure from the Power Steering system. The ABS sensor is mounted on the rear diff.

So how was the ABS integrated with the braking system?

That's my question too. Is there a different master cylinder with an extra line for the ABS actuator? If so, could I just plug it? Or are the MCs identical?

 

[fourwd1]

Both the brake lines and the PS lines pass through the ABS actuator. The 2 fluids don't mix , the ABS actuator just uses the pressure, like the PS gear box does.

That's why you have to bleed the brakes on an ABS equipped truck with the engine off and running.

 

[KidVermicious]

So the MCs are the same. Thanks fourwd, your encyclopedic knowledge of these rigs is always amazing to me.