ABS Master Cylinder / Pump Assembly

[john keefe]

Yes, more beef, but not necessary.

Depends on how much TQ you're throwing at the rear. A decently built 5.0L will be more TQ than Ford allowed/expected with the 2.0L RS, for which they spec'd the beefier, Porsche 108mm setup (not just to accommodate larger CV's). I'd suspect that if simply re-drilling the 100/105mm stock stubbies would have worked, the Ford bean-counters would have pushed that rather than, God forbid, pay a little more for the 108's.

[Ed Lijewski]

It occurs to me that full fluid flushing should help prolong service life of MC seals. I've not done a truly full system fluid flush on either of my Scorpios. Closest I've come to that is a full front or full rear manual flush following a caliper exchange.

But those flushes were done mostly to bleed air using a vacuum pump or gravity flow.

Earlier this year I bought a pressure bleeder; boy does that work better. I used it on a Scorpio after replacing a rear caliper, and on a XR after installing a new master cylinder. I ran enough fluid through the XR to flush it completely but IIRC on a Scorpio I may have lazed out and just bled/flushed the rear.

FWIW, a pressure bleeding alone I assume won't completely flush the ABS pump/accumulator but it will put fresh fluid in the brake lines and fluid reservoir. Any system that bleeds down somewhat overnight would benefit from fresh reservoir fluid.

The research on MC retrofitting is valuable and aporeciated. (I have two full ABS units each of moderate mileage to swap in if/when necessary but after that...?).

YMMV

[my8950]

Earlier this year I bought a pressure bleeder; boy does that work better. I used it on a Scorpio after replacing a rear caliper, and on a XR after installing a new master cylinder. I ran enough fluid through the XR to flush it completely but IIRC on a Scorpio I may have lazed out and just bled/flushed the rear.

Which did you purchase? Part number and/or link?

[Ed Lijewski]

This one:

https://www.amazon.com/Motive-Products- ... 2557&psc=1

I paid less, something a bit over $30 IIRC, by accepting the offer discount on the item for signing up for Prime, which I dropped before the end of the free trial month. (I avoid or shed as many recurring parasitic money sucks that I don't need as possible.)

YMMV

[brokencase]

It is easy to flush the brakes. Start by taking a turkey baster and suck out as much fluid out of the reservoir as you can. Then top it off with fresh fluid.

The rears will "power flush" automatically if you crack the rear brake bleeders slightly and keep the master topped off (do each rear individually).
You turn the key on and the ABS will pump it all out.

The fronts can be flushed with a speed bleeder or having an assistant pump the brakes, again top off the fluid in the master.

I did this in 2016 and I will do again in Spring 2022! I go by the darkening of the fluid in the master.

[Ed Lijewski]

The rears will "power flush" automatically if you crack the rear brake bleeders slightly and keep the master topped off (do each rear individually).
You turn the key on and the ABS will pump it all out

The SM says-

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20211221_145645_copy_858x1080.jpg (204.57 KiB) Viewed 10951 times

-the pedal must be depressed with the pump running and held for fluid to flow through the rear system. It implies there are two people, one depressing the pedal and holding it and the other then tightening the bleed screw to prevent air being sucked into the caliper.

That"s why I've not done it that way as I work solo.

Are you saying the pump when running will move fluid through the rear lines without the pedal being depressed? I don't understand how that's possible.

And, if with the pump running and pedal depressed fluid flows only to the rear calipers that suggests the ABS only operates on the rear wheels. My single experience braking extremely suddenly actuated the ABS which seemed to work on front and back wheels.

Confusing.

YMMV

[Ed Lijewski]

How to check the accumulator video:

https://youtu.be/Lum5ceALGNI

YMMV

[brokencase]

I think I read somewhere on this forum (or perhaps in the old archives) regarding the utilization of the ABS pump to push the fluid out on the rears.

This is the method I used. I did the rears and then i conventionally bled the fronts.

You don't let the pump run very long, and you only crack the rear bleed screw slightly.

[Fresh Air Inspector]

Hello All,

The January 2022 issue of Hemmings Motor News (the thick one with all the cars for sale), has an article on page 46 about converting a Buick Turbo Regal from the 'Powermaster' (aka Teves II electric/hydraulic), brake master cylinder over to a standard vacuum servo master cylinder. It is a 3.5 page article with lots of pictures. They use a dual diaphragm servo and a 2 port master cylinder, no ABS from what I can see. The conversion is very simple as a company called Kirban Performance has produced a conversion kit.

Apparently these systems are referred to as 'Problem Master' by the vehicle owners.

Although not applicable to a Scorpio the article is interesting none the less and does highlight that others are considering this type of conversion.

I don't have an update on my conversion. I have all the bits except the master cylinder which isn't scheduled to arrive until early January. One initial challenge I see is the push rod that connects the servo to the brake pedal. The Mustang servo I have uses the typical 'pivot bolt' (13mm / 1/2"), hole to match the one in the pedal arm. Need to investigate how this issue can be solved.

For those of you celebrating Christmas, enjoy your time with family and friends where possible in these Covid times. All the best for 2022.

[asifahmed]

Hello all

This may be of interest to owners: a potential replacement ABS pump ??
https://www.ebay.ca/itm/224032231590

ABS Pump Replacement.jpg (31.9 KiB) Viewed 10792 times

I have ordered one to examine and will post pics when it arrives.

Regards
AA

[brokencase]

FWIW, I purchased a used Crown Vic ABS/traction control unit with the associated connector. I put a watch on one on ebay and the seller gave me an offer I couldn't refuse. This will sit on the shelf until that day comes when my Teeve system fails.

I will probably adapt a Crown Vic master cylinder to a compact aftermarket dual vacuum servo. I will 3d print a connector to plug into the existing abs harness connector to bring the relevant wires out to the engine bay to connect to the Crown Vic unit. I'll then run another brake line to the rear in order to have individual lines to each rear wheel.

That's the plan...

[asifahmed]

ABS Pump OEM VS Replacement-1.jpg

(624.58 KiB) Not downloaded yet

Hello all

A follow-up attached are pic of the potential replacement pump vs OEM Scorpio.
Replacement longer o/w seems to match up!??

[asifahmed]

More pics ..too large to attach so here's a link
https://drive.google.com/file/d/1hRZ2fp ... sp=sharing
Regards

[Fresh Air Inspector]

Hello All,

Long overdue follow-up, life and too many projects got in the way. In fact, we've only managed to put less than 1200 km (~750 mi), this year.

First, the responses and views to this thread have been fantastic, a good indicator of a healthy forum, plus we need options to our dwindling spare parts supply.

I had to pull the plug on the planned conversion to a 'standard' brake servo set-up. All the parts I needed were ordered late last year. I received the servo and proportioning valve by the end of December but the master cylinder was a 'backorder' item until I cancelled it in May.

In the meantime I replaced the Accumulator with a known good one and then cleaned / tested all the related brake and ABS replays. System is now working properly with both warning lights extinguishing within ~15 seconds.

Question - does anyone know why Ford did not follow the standard DIN pin out architecture for the relays under the passenger side dash pad? The relay socket are easily 'modified' latter on to allow the use of standard replays. Note; the picture below is from my 1988, I believe the relay colour coding may have changed for 1989.

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Hope it helps,

[brokencase]

Probably because that allowed them to sell their own spares.

However I must say the relays have been pretty reliable over the years. In the early years when one could find a Scorpio in a breaking yard, there were those of us who would yank every darn relay we could grab off a junked Scorpio.
I got a box of them. I think I only replaced one.

On the other hand relay socket contacts are prone to corrosion.