1995 F350 7.5l EFI dually crew cab.

ABS light has been on since I've owned this, and due to weather , etc. , finally getting to a issue. A major issue.

The ABS light is on constantly.


What I have done : To date, two VSS sensors installed ( newest one yesterday ) with a new connector soldered in.
While I had the rear off the ground, got out my borescope and had a look see.
No teeth or damage recorded on the tone ring. Peering in from the fill plug side and also with bore scope found no damage to any of the gearing.

Read up on the how to pull codes and the only one I got, 12 flashes , is apparently there is a loss of hydraulic fluid, somewhere which does NOT jive with hands on eyes on thorough inspection- meaning, none of the four show any sign at all of any leakage. Zero loss seen. MC remains at the same level its been since day one.

117,600 original miles on tis.
I've found no breaks on the wiring, so far( getting behind the left saddle tank is a bugger) and so I am told and confirmed, ther is one main connector on left frame rail buried behind left tank.

So-!...seems like if there was a loss of fluid, I'd seen the damn stuff by now but after a year of getting this on the road, driving it, seems unlikely I'd be losing fluid when it remains the same.

Anyone happen to have some insight on this?

IT's got gremlins living in the wiores I beleive and even after putting out cookies and water, they haven't left.

 

Probably the ABS, um, hydraulic valve thingy on the frame below the gas pedal has deteriorated internally. It's not a cheap item, but if everything else is good, it's the only thing left. Read up on what it does and how it operates and it's failure fits your symptoms.

 

Did all that to include this bit.

RABS Code 12 Pinpoint test.pdf

All testing completed and I got nothing.
Float works. Proved that out by keeping it under and then looking at I/P. Once released, went off.

That module from external view doesn't appear to be faulty.
Helper turned the key while I had my hand on it feeling and listening to it cycle. Once as it should.

No LED for 3rd brake light- read up on that as well.

Net gain of zero.

Down over, 2nd and 16.

 

That file link is just a shortcut to the Downloads folder on your computer. When I hover over it I see this at the bottom of the window:



Not to call you out or anything. I don't know how to upload document files either. ¯\_(ツ)_/¯

 

not to call you out....gee...thanks.

Try this then.

 

The correct term is, ABS module.

 

Ah, ok. Learned something new.

 

Code 12 is generated when the anti-lock electronic control module detects that the brake fluid level in the brake master cylinder reservoir is low for one or more seconds during an anti-lock stop. It can also be generated by a short in the stoplamp circuit. Possible Contributing Base Brake Component/Vehicle Wiring Concerns Low brake master cylinder reservoir fill level Fluid leaks in vehicle brake system Worn or damaged fluid level switch, or fluid level switch circuit shorted to ground Brake master cylinder reservoir float that sticks in the bottom of brake master cylinder reservoir or does not float Damaged diode/resistor element in red brake warning lamp circuit Damaged ignition switch Ground short in Circuits 512 (T/LG) or 531 (DG/Y) Damaged anti-lock electronic control module


Learning only stops when the biologics cease.

 

Issue, resolved.

Secret kept.

 

Since for some reason you won’t say and based on

“Float works. Proved that out by keeping it under and then looking at I/P. Once released, went off.” from post #3

I’m going to say a new master cylinder fixed it.