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Discussion Starter · #1 ·
After having 2 NEW MCs fail I am looking for an alternative. Has anyone used this unit from Jegs or another vendor.. :confused:

Jegs Brake Booster...

Thanks... :D
 

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Discussion Starter · #2 ·
ttt
 

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Discussion Starter · #4 ·
OldGuy... Yes, but they were new and not re-built. They both lasted about the same time, 2 weeks. then started sucking massive amounts of air into portion of MC that controls the back brakes. I ran 3 liters of fluid trying to clear the problem... :eek: At that point I said enough was enough. Two weeks is just stupid... The Jegs unit is made by Stainless Steel Brakes Corp. so the quality is there. Tristate is making me some new lines and a adjustable prop valve setup. This should solve several problems including being able to get at the MC res. I am also replacing the wheel cylinders with NEW ones from Motocraft...
 

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Chris,
I have been following your posts on your brakes.
Have you made sure your M/C pushrod is going straight into M/C throughout full travel?
Make sure it is not binding and pushing to one side, causing premature failure of M/C internals.
Just a thought I had.
Jack

[ May 25, 2004, 12:19 PM: Message edited by: stremboli ]
 

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Discussion Starter · #6 ·
Jack,

Used enlarged original hole in FW. Everything looked like it lined up OK. Pedal is smooth. I believe the angle changes slightly as the pedal goes in, but this is normal… Thanks for the thought… I am totally stumped by this one. The SSB unit from Jeg’s looks like a good solution. I will keep your thought in mind as I do the install this weekend and let you guys know how it went…

Thanks…

Chris
 

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Chris, I meant the hole in the M/C that the rod goes in. If is not going in straght throughout pedal travel, it will push the M/C piston radially in the bore. This could cause it to wear prematurely. The rod should be centered thru all travel and not hit the side at all or it will push the piston sideways. I saw this during my build before I had the pedal mod done.
Good Luck
Jack
 

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stemboli makes a good point

Cobra Earl had this issue and always had poor brakes (though no failures) and he wrote about how he had corrected it.

I was in the build phase right then, so looked at the geometry (see drawings of this) I definitely had side binding of the pushrod (Whitby adjustable PR).

I altered the pedal pivot point (per Norcal website) and made sure while the MC was dry that I had true tracking -it is an arc, but can be kept centered - and full pedal travel.





BTW I have the std Jeep MC , without booster and it has worked fine.

hope this helps.

Rick

[ May 25, 2004, 08:32 PM: Message edited by: Zulu ]
 

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I used Jeep MC with the mustang pushrod that has the offset. The straight pushrod looked like it was not parallel with the MC and by pushing in on the pedal it looked worse. By offsetting the pushrod down, it looked like the travel would be closer to parallel. I don't have everything hooked up yet, but the geometry looks better.
 

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If taken from the donor, everything lines up just as it did from the donor, from pedal to pedal box to arm to booster to MC to dist. block. THAT is why I chose to go the donor booster route. If it stoped a car that weighed 1000 lbs. heavier just fine, it shouold have no problems stopping the roadster. Nothing to second guess, no alignment issues (except the frame mods :D ) everything works JUST AS IT DID IN THE DONOR.
 

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I Have a SSBC MC on my '66 Mustang. It's been there for about 10 years now. The outside looks a little rusty. But the inside still looks new. I would recommend thier parts to anyone.
 

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Discussion Starter · #12 ·
I am going on what Rickster said. My booster is in the same hole (slightly larger) that came from FFR to mount the MC, minus booster. If I have a misalignment it is due to the frame for the pedal box being welded in the wrong place (Mr. Pink knows all about this…), BUT it will be to the booster and not the MC. The alignment between the booster and the MC is absolutely guaranteed to be perfect due to the not-optional mating of the booster and the MC… being that they are both stock …!!!

That is what is so troubling… I know the MC is running in perfect relationship with the booster, yet it is still failing, twice…

When I change out the system this weekend I will set up a level and square to get a read on the relationship of the hole in the firewall and the position of the pivot on the brake pedal to the booster. I have come to distrust the brake system which, in it’s self, is a really big problem. I am fairly sure however, that this relationship (booster) is not critical…

The part from Jeg’s will solve an additional problem, that of not being able to access the filler to add fluid. Another PITA… Thanks everyone, I really appreciate all the feedback…

[ May 26, 2004, 12:13 PM: Message edited by: Chris L. ]
 

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I can't say that I fully agree 100% with Rickster.

The mounting of the Pedal Box and the firewall alignment may be as much as 3-5 deg out (Both vertically as well as horizontally), my pedal box did not just bolt up without a little persuasion (and many threads here confirm others had same issue). The angle of the MC is set by the strong steel FW part (cannot change unless using spacer that is wedged), and the Pedal box is light weight pressed steel and can be moved side to side. Also using 1 , 2 or 3 spacers also changes things (I have one spacer). Lastly the MC to Pedal box is not exactly 180 in line, the Thick FW is not perpendicular to the struts that the Pedal box bolt to, close but not 90 deg.

We also optionally choose - many of us - to do a pedal modification for more power on manual brakes (you probably have not done this because of booster) all of which changes the total geometry. Understanding the variables helped me resolve my alignment issue.

So saying that it is exactly the same as the Donor is not 100% accurate, BUT it is similar enough to guess it should work without too much hassle.

long winded yes , but I am an engineer. :D

Rick
:D
 

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Discussion Starter · #14 ·
ZULU,

Please check my edited post above. It can't be the MC alignment...!!! BTW, I am also an engineer (EE)... :eek: :eek: :eek:

[ May 26, 2004, 12:40 PM: Message edited by: Chris L. ]
 

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Engineer here too.....Zulu has a point though. I was considering the above statement as if the firewall had already undergone modifications to get things aligned up properly, and unstressed prior to installation. This is an outside chance....but I remember there being quite a radius that flowed around the outside protrusion that got feed throught the enlarged hole, if your hole had sharp corners or protrusions it might be possible that a small hole/crack was getting worn into that radius?
 
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