and when I shut the truck down the pump (I think- sound coming from where 6 or so brake lines go into a mechanism on driver side) was making a clicking/whinning noise. It didn't stop until I disconnected both batteries. The lights came on about half way home and at the same time.

I looked at the brake resevoir and it was a little below the add line. I connected the batteries for a second and the sound started instantly.


HELP..... What could it be? What should I do? Thoughts....

 

i think the booster is vacuum fed, does your idle or rpm position effect it?

 

my 98 is hydro boost, but it may have just been from low fluid level, but since it was low you might inspect for leaks. or at least check brakes for wear.

 

You will probably have to scan it for the ABS codes.

 

It's probably the ABS controller or CAB (Controller Anti Lock Brakes), it's the brains of the ABS system and is the black box on top of the HCU or (Hydrallic Control Unit) the part with the six lines and a small motor. Instead of disconnecting the batteries you can pull a fuse dedicated to the ABS.

To repair you need to replace the CAB with a new one then you need a DRB III scan tool to set the pinion factor (so it knows what rear end the truck has) and tire size. The CAB has four screws hoding it down and can be easily seperated from the HCU. There are a few plungers between the two but no fuild will leak out.

 

BTW the exact same thing happened to my 04 and I repaired it myself.

The hard part is getting the scan tool. If you have a friendly dealer you could swap the part and let them set the pinion factor or you could rent one from SPX Miller Tool.

 

Any Idea how much the CAB is?

Is it alright to drive it around without a fuse in the ABS?

Thanks

 

You won't hurt anything with the fuse pulled, just no ABS but that's not working anyways.

I'm just guessing but maybe $250. The link is a parts source and it says about $330 but I think that's the whole tamale which would entail a system bleed (DRBIII needs to be used again for that to cycle the plungers to get air out of the HCU and then you bleed the brakes a second time.

BTW a system bleed is a good idea anyways and through research I found out it should be done on a regular basis, the interval would depend on the type of fluid used.

https://www.trademotion.com/partloca...98&catalogid=1

 

I hate ABS so maybe I'll just leave it out and drive as normal!!!!!

 

Might not be a good idea 'cause the rear could lock up and swap ends on you on slippery surfaces.