Eliminating brake booster, AKA non-power brake conversion

XR4Ti / Sierra / Sierra Cosworth Discussions - Questions, problem resolution, general talk, technical tips and modifications.
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by merkurdriver »

timxr8 wrote: These ABS setups have been used on many cars and still work exceptionally well. Jags, Mercedes, Cadillac,
Sierra Cosworth,

:cheers
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by John V »

merkurdriver wrote:
timxr8 wrote: These ABS setups have been used on many cars and still work exceptionally well. Jags, Mercedes, Cadillac,
Sierra Cosworth,

:cheers
Yeah well dem Crossways Injur-nears din't know sheeeeeeut!


Re: Eliminating brake booster, AKA non-power brake conversio

Postby drdanteiii » Fri Jan 02, 2015 1:07 pm

xrattiracer wrote:the scorpio master is not hydroboost (hydraulic, driven from the power steering pump) but rather electric..




oh dear god. I can definitively say that I want nothing to so with an electronic brake booster. hahaha.
Always makes me worry when I see people laughing at excellent ideas---and its clear they have no idea what they're laughing at.
Last edited by John V on Mon Jan 05, 2015 12:10 pm, edited 1 time in total.
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by drdanteiii »

John V wrote:

Oh well, thtas a shame as the Scorpio booster (eletric motor runs the hydraulic pump which charges the pressure accumulator is very simple, normal ABS stuff, just skip the poncy ABS crap) it works brilliantly..

I haven't asked, and you haven't bothered to say WHY you want to go dual masters.. But the EASIEST thing is to copy what Ford themselves did:
Thanks for the all the info and pictures.

Actually, I don't believe I said that I wanted to go dual master necessarily. I want to eliminate the vac booster to clear the valve cover on the mod motor swap. I'm not against going to dual masters, but its certainly not a requirement. I'd actually prefer a single master (dual circuit) with an adjustable proportioning valve.

right now the brake system is 100% stock.
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by timxr8 »

You could also go with a tandem master cylinder and pull the remote booster from an 80's jaguar. Then you can mount it anywhere. Same booster as the Scorpio/Sierra.
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by klork »

What john V posted was basicly what i did. Except I didnt modify the stock pedals. I went with a set of tilton pedals I also switched to a hydraulic clutch at the same time. I hated the cable clutch.
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by John Brennan »

I know it's been beaten to death, but reading threads like this always underscores the point that the XR4Ti should have gotten the same braking system the Scorpios/Cossies got, even as a running change. If you're not going to improve a car during the model's life, don't expect sales to improve, either.

What I wonder in re these braking units is are they still available new, and for anything resembling a reasonable price, or do we have to deal with used parts? As brilliant as any design may be, when the parts are a quarter of a century old, it doesn't inspire the greatest confidence. You have to be able to rely on your brakes, especially if you're going to drive the car "in anger."
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by boost_is_fun »

John Brennan wrote:You have to be able to rely on your brakes, especially if you're going to drive the car "in anger."
For sure. I lost my brakes while driving 35mph, it was not a fun experience. When I can afford it, I will at least be replacing my drums with some discs.
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by Ed Lijewski »

Rarely does an NOS Scorpio ABS pump unit appear FS and typically at lots more Benjamins than a standard Merkurista wants to pay. Someone here from So. Cal. reported having his unit rebuilt and was pleased with the result and cost, but he didn't share details on that.

I have a Scorpio and two '88 XRs. Categorically in my experience one XR has an even slightly firmer and better brake pedal response than does my Scorpio (which has no malfunctions per the two MIL lights, currently). My other XR with higher mileage could benefit from an ew master cylinder which are no longer available in remanned form; new late model XR MC units cost ~$200.

My Scorpio with ~150K has had ABS/MC issues with the pressure accumulator and fluid pressure switch. Occasionally a new accumulator is available on Amazon or elsewhere for ~$100+; new pressure switches are equally rare and more dear--the last I saw on Ebay was offered at over $300. I bought a new NOS accumulator and was surprised to find on install that it didn't hold pressure as well as my old accumulators. The accumulators are filled with nitrogen which apparently can leak through the internal diaphragm over long periods of time.

Used accumulators and pressure switches can be pulled out of cars in junk yards that used the same Teves ABS/MC system, but you won't know if they're good until you install them. Note also that those Teves units have different physical packages (pump body, fluid reservoir, accumulator placement...) from the Scorpio unit so they're not an easy drop in to an XR.

Junkyard-ing to keep an OEM Scorpio unit working fine is worth the effort; but it isn't for swapping and maintaining into an XR.

A regularly serviced and properly equipped XR disc/drum system works fine for me. Oh, and I have two spare Scorpio ABS/MC units which I have no need for or intent to install into my XRs.

It's just a fad. Like swapping discs for rear drums. IMNSHO. :BS

YMMV 8)
Last edited by Ed Lijewski on Fri Jan 23, 2015 8:24 pm, edited 1 time in total.
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by boost_is_fun »

I just have a hatred for drums after a spring pulled loose when I was trying to replace the wheel cylinder, and cut my finger open. The old brake fluid that dripped into the cut was no bueno as well. I just like the simplicity of discs.
Last edited by boost_is_fun on Sat Jan 24, 2015 5:07 pm, edited 1 time in total.
Connor
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by Ed Lijewski »

You don't get better braking from disco-ing the XR rears , NOOB.

But saying and repeating it does make you believe it, just as Goebbels said.

If you disagree, please find comparative objectively verifiable statistics to share here.

YMMV 8)
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by boost_is_fun »

Ed Lijewski wrote:You don't get better braking from disco-ing the XR rears , NOOB.

But saying and repeating it does make you believe it, just as Goebbels said.

If you disagree, please find comparative objectively verifiable statistics to share here.

YMMV 8)
Alright, I'll edit my post to say I just like the simplicity. As stated above I just despise drums because of all the springs and crap on them.
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by John Brennan »

Fuggetaboutit, Connor. The overwhelming majority of us automotive enthusiasts understand the improvements afforded by discs over drums, which is why no serious road car has had them for probably over thirty years, and why they have been absent from any serious form of racing for well over half a century. The Earth is still round, and the Sun isn't rising in the West. :wink:
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by xrattiracer »

for those of us that have significantly raised the power output of the engine and improved the suspension, the stock brake system is no longer adequate regardless of the condition it is kept in.
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by John V »

Ed Lijewski wrote:You don't get better braking from disco-ing the XR rears , NOOB.

But saying and repeating it does make you believe it, just as Goebbels said.

If you disagree, please find comparative objectively verifiable statistics to share here.

YMMV 8)


So oh wise one who has spent a whole lifetime working at the forefront of automotive design, tell us then just why do manufacturers use discs brakes in general, and rear disc in particular...PLEASE! :notworthy

Oh massa I'z all prostrate on the ground in da dirt just holding my breath in joyous anticipation of your deigning to share with us the truth, the reality, the deep inner secrets to us who are so deluded and lead us back to the light of your wisdom :notworthy ...
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Re: Eliminating brake booster, AKA non-power brake conversio

Post by Mike McCreight »

Ed will take us all there, and never once use the clutch.
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