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Discussion Starter #1
Hi

I have been progressively fixing the brakes on the Junior, and this past weekend I took the boosters apart to see if they where the issue. >500ml of brakefluid splashed out of both Boosters, so clearly they have a problem.

I dont have time/money to fix them, as the kits available here are quite pricey, and I need to get the brakes working by Thursday for track practice.

Does any other manufacturer (i.e. one who's parts are easier to get) that uses the same brake-pipe fittings? I need to join the two male fittings to bypass the boosters.

Any ideas guys? The car has the pedals that comes up from the floor (MC under the seat) and I've heard that alot of guys run their cars without the Boosters. I know what a car without boosters feels like, and for a track that is acceptable... I just need them to work!!
 

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I found a fitting at the local auto parts store (NAPA,I think). A tube a little over an inch long with female threads at both ends that the brake line fittings screwed into. It's a fairly common piece since people often use it to splice the preflared pieces found at the parts stores. I think I carried one of the brake lines in with me to check the fit.

Bill
 

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Discussion Starter #3
Thanks Bill

Went to buy some F-F adaptors today, crap expensive, but a whole lot cheaper than buying boosters.

Now Im just hoping its acceptable on a track! will fit them tomorrow, then going to the track to practice on thursday
 

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Please note that Alfa used two different types of brakeline flares; an inverted double flare (concave) and an ISO bubble flare (convex). All the Alfas of the period that I've seen use the ISO bubble flare in the hydraulically operated boosters. The threaded fitting is a 3/8" x 24.
 

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Discussion Starter #5
Thanks Papajam - I did take a booster with to make sure. Aparently (according to the sales person) thats why its so expensive, because its such a wierd thread/coupling.
 

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Yay! It worked!

Spent the day at Zwartkops raceway yesterday, and the brakes finally felt good! I now (obviously) have to press harder, but atleast its not spongy anymore. I can now set a brake marker, and hit it lap after lap! One thing I did notice is that I consciously have to brake harder - a couple of times I missed the apex because I didn't brake hard enough! But I'll get used to that soon enough. Beat my previous best at this track by 2 seconds! And there still is probably half a second to a second while my confidence gets up.

THIS CAR ROCKS!!
 

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A long time in the future, I'm thinking about removing the booster altogether and using a twin MC set-up with a balance bar, all encased in a waterproof box next to the chassis rail. From memory, I think the very earliest Sprint GTs ran without a booster and they used a 20mm MC rather than a 22mm - was this to reduce the amount of pedal pressure required? I too would swap even a small amount of sponginess for a firmer pedal feel, even though my current booster/MC set-up works as well as it's ever going to.

Alex.
 

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Yes, the smaller MC diameter compensates for the lack of boost. Thru 1967 or so the alfas used single circuit brakes with 20 mm MC. About that time the boosters came in, using 22 mm MC's. The 20 mm MC will have more pedal travel; but the booster with the 22 mm MC made the brakes a little softer, so the pedal travel ended up about the same. I personally prefer racing without boosters - the hard pads often used on a track (for heat) are hard to modulate (get just a bit of brake instead of all-on or all-off) and the booster just gets in the way.

Dual MC - one for front and one for rear with a balance bar - is classic racing, especially with a remote adjuster to correct for the rear getting lighter as the fuel is used. But a good rear proportioning valve with a single MC is almost as good, and you can get both knob and lever adjusters for them. One of the best advantages of dual MC's is fail-safe....

Robert
 

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Robert,
Just took apart my master for the '65 GTA expecting to have to send it out to be resleeved because of pitting, etc. It was perfect on the inside, but what astonished me was that when measured it was 22.5 mm. This car has never had a booster! I was expecting a 20mm bore. I am converting the front spindles to later model so I can use GTV 6 alu. calipers and ATE rear calipers.Any thoughts?
Thanks,
Ed
 

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Robert,
Just took apart my master for the '65 GTA expecting to have to send it out to be resleeved because of pitting, etc. It was perfect on the inside, but what astonished me was that when measured it was 22.5 mm. This car has never had a booster! I was expecting a 20mm bore. I am converting the front spindles to later model so I can use GTV 6 alu. calipers and ATE rear calipers.Any thoughts?
Thanks,
Ed
Pick the spindles carefully. There are two different 2L spindles - with different caliper bolt spacings. Only one fits the Bremo al calipers (Milano's are a common source). The early ATE spindles from about your car's era have the right spacing for the Bremo's. Slightly later ones are OK too (from a 1750 perhaps?). Much later and the ATE calipers from the 2L's were about a half-inch wider bolt spacing (AFAIR its 4 inches vs 4 1/2 or 4 1/4 inches). The 1750 and later spindles are taller than the 1600's, incorporating a bit of the "knuckle-riser" idea used on the racing GTA's to improve bump camber. But be careful about the overall geometry - lowering your car with shorter springs usually leads to some or very significant bump-steer, which makes the car pretty squirely to drive - as most of the racing GTA's of that era were!

Choose a stock street pad for the bremos for most use. Carry a set of high performance ones for TT and AX - it's barely a half hour change over after a bit of practice.


Robert
 

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Robert,
I've got the right spindles ('68 or '69 can't remember which). The taller NR effect plus the alu. calipers and getting away from the Dunlops was the goal. I'm using Porterfield R4S pads which I really like (have them on my 1750 GTV). Springs are stock street GTA. so no lowering.
My biggest concern is the MC bore size. Is it too big? I really don't like boosters and this car never had one. Guess I'll just have to drive it and see.
Thanks,
Ed
 

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FWIW, I have small 1300/1600 ATE's on a GTA up front and the ATE's with small pistons in the rear. The car has a 22mm BMC (stock late GTA/GTAjunior set-up). I have run it both with and without booster. I prefer the feel with booster but it defintitely is drivable with very good modulation, if a bit wooden feeling without booster. If anything, the set-up you are considering should have possibly slightly more piston area and thus lend itself as well or better to the 22mm BMC w/o booster. But as you a say, you really need to try it ...
 

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Yay! It worked!

Spent the day at Zwartkops raceway yesterday, and the brakes finally felt good! I now (obviously) have to press harder, but atleast its not spongy anymore. I can now set a brake marker, and hit it lap after lap! One thing I did notice is that I consciously have to brake harder - a couple of times I missed the apex because I didn't brake hard enough! But I'll get used to that soon enough. Beat my previous best at this track by 2 seconds! And there still is probably half a second to a second while my confidence gets up.

THIS CAR ROCKS!!
Told you so... ;)

Wait wasn't that last year already :p
 

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Discussion Starter #15
Yes yes :) was last year - but I wanted to give the boosters the benefit of the doubt... hows your alfa doing?
 

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To disconnect and remove the booster on my 65 Sprint GT, can I take the brake line from the master cylinder off the booster and connect it to the " distribution" block in place of the outlet line from the booster?

Rob
 
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