Hello all, a few days ago my brakes became very soft on my '97. They feel firm when you first brake but then the pedal fades to a few inches from the floor. I replaced the master cylinder yesterday thinking that was the problem, and it made no difference. Spent today bleeding the brakes with no improvement. Cant find any leaks and the brake lines look fine. The truck has the 4wheel ABS. Any ideas or help greatly appreciated. Thanks.

pat

1997 F150 5.4 Lariat
1987 F150 5.0 Lariat

 

If your new master cylinder isn't internally leaking, then I suspect your ABS module is bad.

edit: Welcome to the site!

 

the rubber lines to the calipers break down with age. They may not blow out, but they expand when pressure is applied to the pedal.

 

Do you have 4whl ABS? If yes, you likely have a bad HCU. AndersonS is correct.

 

I checked the brake lines and didnt see any expansion with the brakes applied. The truck does have 4 wheel abs. How much are the HCU's and is it a Ford only part? I'm not seeing any online anywhere. Love the site and I appreciate all the help!!

pat

 

I just visited my local Ford dealer. The HCU is $959, and that doesnt include the electric unit on top.

 

If you're not opposed to the idea, there are a TON of 97-03 F-150's in the salvage yards. I don't know the prices of those parts, but it's probably less than $959. My local salvage yard has a nice return policy too.

 

http://www.ebay.com/itm/F150-ABS-Mod...2194d1&vxp=mtr

You will, of course, need to confirm part number and fitment.

I bought one from this seller. The transaction went perfectly.

 

Thanks guys, I wasnt having any luck on ebay typing in "HCU", but I typed "ABS pump" and found a few. I'm gonna find a used one, $959 is to rich for me.

 

post up the part number I'll see if I can find it..

 

YL34-2C346-AA. That was for my '03. I don't know if the '97 had the same part.

PS - the one on eBay I referenced is $211 or best offer. Brand new factory part.

 

Not to hyjack, but on a side note.... has anyone ever deleted the HCU and just ran the lines from the master cylinder to the brakes? What would happen?

 

Rock auto has a ABS control module for 70 bucks modulator for 128. I'd look there..

 

You'd have an ABS light on the dash and full control of the brakes, but no steering during a panic stop.

 

The control module is the electronics and magnets that run the HCU, not the HCU. The modulator is for rear ABS only, I believe. But perhaps that is a solution.