Help bleeding HCU on a '91

[aclerok]

Hello,

I'm a new member to the forum but have been reading your posts for several months when I run into issues. First I would like to say thank you; I have picked up many tips from you all that have saved me a lot of money.

Now for my question. We bought our explorer used years ago and it has always had a soft/spongy brake pedal. We've since replaced the front pads/rotors, rear drums/pads, MC, power booster and still have this problem with the pedal. From reading through the posts on this board I have found that the reason for this pedal (given what we've already done to the brake system) is most likely from trapped air in the HCU for the RABS.

I know you need the T90P-50-ALA to cycle the solonoids and be able to bleed this unit, but I am having no luck finding one (or anything else that would work). I did actually run across one on eBay, but they want $250 dollars for it! For that price I'll deal with the pedal.

I've seen in other threads that there is something made by Thexton that should do this, but I cannot find out what part this actually is. I've also read that someone made their own homebrew that cycled the solonoids as well.

Does anyone have any info or tips for me on this? Is there perhaps a code reader out there that will also cycle these?

Thanks,
Dan

Update:

I've done some more reading and it seems that if you have RABS, then you do not have and HCU.

Any suggestions as to why I could be having this low pedal?

 

[dartman]

bleed master

It sounds like you said you replaced the master cylinder. Did you bleed it before you put it on.If not,try having someone pump brake pedal & hold & loosen lines one at a time at the master. Be sure to catch brake fluid as it damages paint. Then bleed system again--farthest wheel away from master first then work towards master .Your abs valve should be a manual one--no pump built in so you should be able to bleed the brakes this way.

 

[aclerok]

Dart,

Thanks for the input. We did a bench bleed on the master before putting it on, so I don't think that that is the problem.